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26 May 2025
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4 min read
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by YINI Editorial team
Nutri-dense food Q&A

Focus on the bioactive peptides in dairy and yogurt

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The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
casein dairy Lactoferrin peptides whey
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Dairy products, including fermented varieties such as yogurt, are not only rich in macronutrients,  essential vitamins and minerals, but also serve as a source of bioactive peptides—short amino acid sequences that influence various physiological processes. Among these, lactoferrin, casein-derived peptides, and whey-derived peptides have been studied extensively for their health-promoting properties.

What are the bioactive peptides

In addition to providing the basic nutrients, milk and dairy products provide an array of biologically active compounds, includ­ing bioactive proteins, that are initially meant to support infant health.

The majority of bioactive peptides derive from milk casein (β-casein, αs1- and αs2- casein and κ-casein), from whey β-lactoglobulin and α-lactalbumin or lactoferrin (1). They are produced by enzymatic hydrolysis of these milk proteins, either during digestion or due to the process­ing or fermentation in dairy products, and are thought to present an array of functions including antioxidant, antimicrobial, immunomodulatory, anti-inflammatory, antihyperten­sive, insulin signaling.

Peptides in yogurt and fermented dairy products

Fermented foods (such as fermented milk, cheese or yogurt) are sources of probiotic organisms that contribute to generate bioactive peptides, various amino acids or enzymes that provides numerous health benefits.

Yogurt fermentation, primarily through Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, enhances peptide bioavailability. Proteolysis during fermentation liberates bioactive peptides from casein and whey proteins. These bioactive peptides have wide range of therapeutic potentials that includes antihypertensive, ACE-inhibitory, antioxidant, antimicrobial, immunomodulatory and cholesterol lowering peptides (11).

Lactoferrin

Lactoferrin is predominantly found in mammalian milk (with high concentrations in colostrum, ~7g/L, and lower concentrations in mature milk, ~1 g/L). It comprises ~690 amino acids and belongs to the transferrin protein family, with a strong affinity for ferric ions. Its iron-binding capacity is central to its diverse biological functions and underpins its role in defense mechanisms (2,3).

Owing to its capacity to sequester free iron, lactoferrin exerts significant antimicrobial activity by limiting microbial access to this essential micronutrient, thereby inhibiting the growth and virulence of a wide range of pathogens. Beyond its antimicrobial properties, lactoferrin acts as modulator of immune homeostasis. Furthermore, it contributes to gastrointestinal homeostasis by promoting the growth of commensal microbiota, supporting epithelial integrity, and modulating mucosal immune responses.

Therefore, lactoferrin has numerous beneficial properties that may play an important role in maintaining health from fetal life to old age (3).

  • Immunomodulation: Lactoferrin can regulate the immune system. It influences both innate and adaptive immunity by modulating cytokine production, enhancing the activity of natural killer cells, and regulating dendritic cell and T-cell responses (3).
  • Anti-inflammatory properties: Lactoferrin demonstrates anti-inflammatory activity through the downregulation of pro-inflammatory cytokines such as IL-6, TNF-α, and IL-1β, and the inhibition of NF-κB signaling pathways (3).
  • Antioxidant function: Lactoferrin reduces oxidative stress, by chelating redox-active iron, thereby mitigating hydroxyl radical formation and limiting oxidative tissue damage (3).
  • Antiviral and antibacterial activity: Lactoferrin has a broad-spectrum antimicrobial effect. By sequestering iron, lactoferrin creates an environment unfavorable for pathogen growth. It also binds to lipopolysaccharides and viral surface receptors, impeding pathogen entry (4,5).
  • Gut health: Its broad-spectrum antimicrobial effects are further reinforced by direct interactions with microbial membranes and surface molecules, and by blocking cellular entry pathways used by viruses. Lactoferrin supports intestinal health by promoting beneficial microbiota and strengthening the gut barrier function (3).

Casein-Derived Peptides

Caseins are the primary proteins in milk (about 80% in cow’s milk), and their enzymatic digestion yields several bioactive peptides with diverse health effects.

  • Casomorphins: These opioid-like peptides (e.g., β-casomorphin-7), derived from the digestion of the β-casein of dairy products, modulate gastrointestinal motility and immune responses. Some evidence suggests potential roles in neurological conditions, though results remain inconclusive (6).
  • Casein phosphopeptides (CPPs) harbor interesting antioxidant and anti-inflammatory properties. CPPs also enhance mineral absorption, especially calcium and magnesium, by forming soluble complexes with minerals, facilitating their bioavailability (7).
  • Other lactopeptides : Peptides derived from casein (such as VPP and IPP) inhibit angiotensin-converting enzyme (ACE) and may contribute to blood pressure reduction in hypertensive individuals consuming fermented milk products enriched with these peptides (8).

Whey-derived peptides

Whey proteins include α-lactalbumin, β-lactoglobulin, and minor components such as lactoperoxidase and immunoglobulins. Hydrolysis of these proteins generates peptides with anti-inflammatory, antioxidant, and metabolic effects.

Whey-derived peptides may modulate satiety hormones (GLP-1, CCK) and have been associated with improved insulin sensitivity. Studies reported better glycemic control in overweight adults after whey protein ingestion (9).

Cysteine-rich whey peptides boost glutathione production, enhancing cellular antioxidant defenses (10).

Dairy-derived peptides, especially lactoferrin, casein hydrolysates, and whey peptides, may possess clinically relevant health benefits, including immune support, antimicrobial action, mineral absorption, or cardiometabolic regulation. Continued research are necessary to better define the dose-response relationships and long-term impacts of these compounds in diverse populations.

References
  1. (1) Søren Drud-Heydary Nielsen, et al. Bioactive milk peptides: an updated comprehensive overview and database, 2024, Critical Reviews in Food Science and Nutrition, 64:31, 11510-11529,
  2. (2) Superti F. Lactoferrin from Bovine Milk: A Protective Companion for Life. Nutrients. 2020 Aug 24;12(9):2562.
  3. (3) Kowalczyk P, et al. The Lactoferrin Phenomenon-A Miracle Molecule. Molecules. 2022 May 4;27(9):2941.
  4. (4) Xu Y, Wang Y, He J, Zhu W. Antibacterial properties of lactoferrin: A bibliometric analysis from 2000 to early 2022. Front Microbiol. 2022 Aug 17;13:947102.
  5. (5) Berlutti F, et al. Antiviral properties of lactoferrin--a natural immunity molecule. Molecules. 2011 Aug 16;16(8):6992-7018.
  6. (6) Thiruvengadam M, et al. β-Casomorphin: A complete health perspective. Food Chem. 2021 Feb 1;337:127765.
  7. (7) Tenenbaum M, et al. Identification, production and bioactivity of casein phosphopeptides - A review. Food Res Int. 2022 Jul;157:111360.
  8. (8) Geleijnse JM, Engberink MF. Lactopeptides and human blood pressure. Curr Opin Lipidol. 2010 Feb;21(1):58-63.
  9. (9) Pal S, Radavelli-Bagatini S. The effects of whey protein on cardiometabolic risk factors. Obes Rev. 2013 Apr;14(4):324-43.
  10. (10) Giblin L, et al. Whey proteins: targets of oxidation, or mediators of redox protection. Free Radic Res. 2019;53(sup1):1136-1152.
  11. (11) Chaudhary A, et al. FermFooDb: A database of bioactive peptides derived from fermented foods. Heliyon. 2021 Apr 8;7(4):e06668.
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19 May 2025
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5 min read
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by YINI Editorial team
Adult Cardiovascular health

Rethinking the dietary guidelines on dairy fat and heart disease  

YINI Editorial team
The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
dairy fats dietary recommendations fat saturated fat acids
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Leading nutrition experts from around the world are calling for a re-think of dietary guidelines on dairy products. Their plea comes in the light of latest research that casts doubt over the long-held belief that regular-fat dairy foods are linked to increased risk of heart disease. Instead, milk, cheese, and yogurt – regardless of fat content – seem to have neutral effects on heart health.

Rather than limiting regular-fat dairy foods, experts suggest focusing on reducing highly processed foods as a more effective strategy for improving heart health.

The heart of the matter: regular-fat versus low-fat dairy foods

For decades, dietary advice has promoted low-fat over regular-fat dairy options as a strategy to reduce the risk of cardiovascular disease (CVD). But scientists have raised doubts over this assumption, and now a group of global experts has published their findings following an international workshop held in Amsterdam in April 2024 to review latest research on dairy fat and heart disease (1).

Their key takeaway? The fat content in dairy foods such as milk, yogurt, and cheese may not matter as much as we thought when it comes to heart health.

Dietary guidelines aim to limit saturated fats in the diet

Most dietary guidelines around the world recommend minimising the amount of saturated fatty acids (SFAs) in food to reduce the risk of developing CVD (2,3). However, the SFAs in the diet come from a wide range of food sources, the main ones often being highly processed foods, followed by meat and dairy foods. Emerging evidence suggests the food source of SFAs affects their link with CVD risk – for example, replacing meat with dairy foods as a source of SFAs is associated with a lower risk of CVD (4,5).

With this in mind, the aim of the workshop was to determine whether there is sufficient evidence to position regular-fat and low-fat dairy foods differently in dietary recommendations.

There is no clear difference to heart health between full-fat and low-fat dairy

One of their major findings is that current evidence shows no clear link between dairy fat and increased risk of CVD. In fact, whether people consume regular-fat or low-fat dairy foods, the impact on heart disease risk appears to be neutral.

In particular, several long-term observational studies on the association between people’s food habits and heart health show the following results:  

  • Total intake of dairy foods is either not associated with or favourably associated with risk of CVD, including coronary artery disease and stroke.
  • No conclusive evidence exists to show that eating regular-fat or low-fat dairy foods is differently associated with most CVD-related clinical outcomes.
  • Eating fermented dairy foods such as yogurt and cheese appears to have no association with the risk of developing CVD.

These findings are supported by evidence from randomized controlled trials, the gold standard in scientific research. Clinical studies show no differences between eating regular-fat or low-fat dairy on markers of CVD risk including cholesterol, blood pressure, body weight, and blood glucose levels.

However, the nutrition experts caution that current studies are limited, and more research is needed in people with different levels of CVD risk to understand the effects of regular-fat and low-fat dairy on markers of heart health.

Cardiovascular risk factors may be influenced by the dairy food matrix

Several components of dairy foods may interact to influence their effects on cardiovascular risk (6,7). These include:

  • The nutrient content and fatty acid composition of dairy foods, which may differ from other foods high in SFAs.
  • The structure of dairy fats within the milk fat globule membrane and the size of fat droplets.
  • The composition and structure of the dairy food matrix, which can be influenced by food processing and fermentation.

Studies show that fats within the dairy food matrix have several biological functions that help to influence cholesterol metabolism, alter digestion and blood lipid levels, and modify signals within the gut microbiome (8). Studying these biological mechanisms may help shed light on the reasons behind the neutral effects on heart health seen with dairy food consumption.

Reducing saturated fats: Cut back on meats or pastries, not dairy

These findings raise questions about current dietary guidelines that promote low-fat alternatives as a healthier choice than regular-fat dairy foods. According to the experts, it may be time to stop focusing on the fat content of dairy foods and instead look at overall diet quality.

In modern Western diets, the biggest sources of SFAs are often processed, energy-dense foods that are low in nutrients, such as highly processed meats, snacks or meals. Rather than eliminating regular-fat dairy foods from our diet, the experts suggest that public health strategies would be more effective in reducing the intake of these energy-dense and nutrient-poor foods  for a larger impact on SFA intake and therefore a greater benefit to cardiovascular health, and continue the work toward a better understanding of the dairy fat behaviour on cardiometabolic health.

“Differentiating low-fat from regular-fat dairy in dietary recommendations is currently not supported by the available evidence in adults. We propose that dietary guidelines for adults should emphasize food-based strategies that are likely to have a greater impact on a population’s SFA intake.”

Lamarche B, et al. 2025

References
  1. (1) Lamarche B, Astrup A, et al. Regular-fat and low-fat dairy foods and cardiovascular diseases: perspectives for future dietary recommendations. Am J Clin Nutr. 2025 Mar 13:S0002-9165(25)00137-6.
  2. (2) Lichtenstein AH, et al., 2021 Dietary guidance to improve cardiovascular health: a scientific statement from the American Heart Association, Circulation 144 (2021) e472–e487.
  3. (3) Johnson S et al, Saturated fat intake and the prevention and management of cardiovascular disease in adults: an Academy of Nutrition and Dietetics evidence-based nutrition practice guideline, J. Acad. Nutr. Diet. 123 (2023) 1808–1830.
  4. (4) Steur M, et al., Dietary fatty acids, macronutrient substitutions, food sources and incidence of coronary heart disease: findings from the EPIC-CVD case-cohort study across nine European countries, J. Am. Heart Assoc. 10 (2021) e019814
  5. (5) Vogtschmidt YD, et al. Replacement of saturated fatty acids from meat by dairy sources in relation to incident cardiovascular disease: the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk study, Am. J. Clin. Nutr. 119 (2024) 1495–1503
  6. (6) Vors C, et al. Dietary lipids and cardiometabolic health: a new vision of structure-activity relationship, Curr. Opin. Clin. Nutr. Metab. Care. 23 (2020) 451–459
  7. (7) Mozaffarian D and Wu JHY, Flavonoids, dairy foods, and cardiovascular and metabolic health: a review of emerging biologic pathways, Circ. Res. 122 (2018) 369–384.
  8. (8) Vors C et al., Milk polar lipids reduce lipid cardiovascular risk factors in overweight postmenopausal women: towards a gut sphingomyelin-cholesterol interplay, Gut 69 (2020) 487–501.
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12 May 2025
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5 min read
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by YINI Editorial team
Adult Fermentation benefits Gut Health

The key to a healthier future may lie in our gut microbiome

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The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
early life fermented foods gut microbiome microbiota pregnancy probiotics
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Scientists are increasingly recognizing the profound influence of the gut microbiome on life-long health, particularly during the formative period from embryo to early infancy. Nurturing a healthy gut microbiome through appropriate nutrition during this crucial time may offer protection against future diseases and potentially impact the rise of chronic conditions around the world.

The composition and function of the gut microbiome – the vast ecosystem of microorganisms living in our digestive system – may play a key role in our overall health. And no time is more important for shaping our gut microbiome than the very early stages of life, research suggests.

The gut microbiome is linked to multiple health conditions

Scientists are ever more discovering links between the gut microbiome and chronic health conditions. The illnesses influenced by the gut microbiome range from chronic immune and inflammatory diseases such as allergies to the development of non-communicable diseases such as obesity, one of the most pressing global health challenges of the past few decades.

Often, these conditions are already present in childhood and adolescence, and have been associated with a gut microbiota composition that differs from that of healthy people.

Health and nutrition scientists at the University of Turku in Finland have reviewed the latest research on potential health benefits of modulating the microbiome during the critical early stages of childhood development (1). Their findings suggest that modifying the gut microbiome through nutritional changes in early life may be central to protecting against many chronic health conditions and increase resilience to global health challenges.

The early years of childhood are a critical window for future health

The evidence suggests that the foundations for long-term health are laid as early as during pregnancy and early infancy. This period represents a time of great change, where immune, metabolic, and microbial systems are forming. Scientists believe that interventions during the first 1,000 days – throughout pregnancy, birth and early infancy – offer a promising time window to improve long-term health and resilience against chronic diseases:

  • Pregnancy: A mother’s health and weight gain during pregnancy can affect a child’s health (2). For example, too much weight gain during pregnancy has been shown to change the gut microbiome of pregnant women, which in turn can act as a driving force for metabolic changes (3,4).
  • Birth: Birth and breastfeeding processes both influence a child’s microbiome development. The make-up of a mother’s gut microbiome – determined by her diet and environment – guides the composition of a breastfeeding child’s gut microbiome during a critical period of immune and metabolic development (5).
  • Early infancy: Introducing solid foods to infants is linked with a significant increase in gut microbiome diversity (6). Studies show that changes to the gut microbiome of infants may help to promote childhood growth, development and health, and to lower the risk of chronic diseases.

Nutrition and gut microbiome are essential in shaping immune and metabolic maturation for lifelong health

Studies showed that our gut microbiome is shaped by what we eat, which has consequences for our long-term health. A balanced diet supports a diverse and balanced microbiome, which helps regulate our immune responses and metabolism. An imbalance of gut bacteria can contribute to inflammation, obesity, and chronic diseases.

Within our overall diet, probiotics (beneficial bacteria) and prebiotics (compounds that feed good bacteria) are emerging as key tools in promoting gut health. Research suggests that incorporating these elements into the diet, particularly during pregnancy and infancy, could significantly reduce the risk of chronic diseases later in life:

  • Probiotics: Evidence suggests that probiotic interventions during pregnancy can lower the risk of obesity and allergy in children. The World Allergy Organization recommends providing probiotics to pregnant and breastfeeding mothers if their infants have a high risk of developing allergies (7).
  • Prebiotics: Studies suggest that prebiotics found uniquely in breastmilk may modify infant gut microbiota, lowering the risk of infection and affects childhood development, which may have an impact on later health (8).
  • Other nutrients: Diet modification during pregnancy can modify the maternal gut microbiome, with potential impacts on metabolic, immune, and clinical outcomes for both mother and child. For example, high-fibre diets increase microbial diversity, while high-fat diets show the opposite effect (9).

The role of the gut microbiome in preventive health

Evidence links the risk of several chronic diseases to changes in the microbiome during early childhood and pregnancy. However, the researchers conclude that our understanding of the gut microbiome’s role in long-term health is still developing. Questions remain about the mechanisms by which diet, environment and gut bacteria interact to shape health outcomes.

The authors emphasize the importance of beneficial dietary interventions during pregnancy, breastfeeding and early infancy. Pregnant and breastfeeding mothers have a unique opportunity to pass on microbial and metabolic advantages to their children through a nutrition supporting a healthy gut microbiome.

By incorporating foods providing probiotics, such as fermented dairy products like yogurt and kefir, into their diet, mothers can promote gut-friendly nutrition from the earliest stages of life. This approach may help curb the rising tide of chronic diseases.

“By promoting the health of pregnant and lactating women today, the health of the next generation(s) may be successfully improved. The perfect tools for this initiative derive from the earliest and most massive source of environmental exposures, namely the microbiome and nutrition.”

Isolauri E, Laitinen K, 2025

References
  1. (1) Isolauri E, Laitinen K. Resilience to Global Health Challenges Through Nutritional Gut Microbiome Modulation. Nutrients. 2025 Jan 22;17(3):396. doi: 10.3390/nu17030396. PMID: 39940253
  2. (2) Rautava, S.; Luoto, R.; Salminen, S.; Isolauri, E. Microbial Contact during Pregnancy, Intestinal Colonization and Human Disease. Nat. Rev. Gastroenterol. Hepatol. 2012, 9, 565–576
  3. (3) Koren, O.; Goodrich, J.K.; Cullender, T.C.; Spor, A.; Laitinen, K.; Kling Bäckhed, H.; Gonzalez, A.;Werner, J.J.; Angenent, L.T.; Knight, R.; et al. Host Remodeling of the Gut Microbiome and Metabolic Changes during Pregnancy. Cell 2012, 150, 470–480.
  4. (4) Cabrera-Rubio, R.; Collado, M.C.; Laitinen, K.; Salminen, S.; Isolauri, E.; Mira, A. The Human Milk Microbiome Changes over Lactation and Is Shaped by Maternal Weight and Mode of Delivery. Am. J. Clin. Nutr. 2012, 96, 544–551.
  5. (5) Bogaert, D.; et al. Mother-to-Infant Microbiota Transmission and Infant Microbiota Development across Multiple Body Sites. Cell Host Microbe 2023, 31, 447–460.e6.
  6. (6) Laursen, M.F.; Bahl, M.I.; Michaelsen, K.F.; Licht, T.R. First Foods and Gut Microbes. Front. Microbiol. 2017, 8, 356.
  7. (7) Fiocchi, A.; et al. World Allergy Organization-McMaster University Guidelines for Allergic Disease Prevention (GLAD-P): Probiotics. World Allergy Organ. J. 2015, 8, 4.
  8. (8) Estorninos, E., et al. Term Infant Formula Supplemented with Milk-Derived Oligosaccharides Shifts the Gut Microbiota Closer to That of Human Milk-Fed Infants and Improves Intestinal Immune Defense: A Randomized Controlled Trial. Am. J. Clin. Nutr. 2022, 115, 142–153.
  9. (9) Maher, S.E.; et al. The Association between the Maternal Diet and the Maternal and Infant Gut Microbiome: A Systematic Review. Br. J. Nutr. 2023, 129, 1491–1499.
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05 May 2025
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5 min read
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by YINI Editorial team
Nutri-dense food Q&A

Focus on casein

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The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
amino acids calcium casein dairy phosphorus proteins whey
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Casein is the main group of proteins present in milk and dairy, accounting for about 80% of total protein. Its unique structure and physicochemical properties give it important physiological roles and are attracting growing interest for its potential benefits for human health. Let’s summarize the knowledge on the composition, physiological roles and potential benefits.

Composition and structure of casein

Casein makes up around 80% of the total protein in cow’s milk. The remaining 20% are mainly soluble whey proteins, such as β-lactoglobulin, α-lactalbumin, bovine serum albumin and immunoglobulins. This high proportion of casein gives milk and dairy products their characteristic nutritional and functional properties.

Casein is not a single protein, but rather a family of phosphoproteins (1). The four main types of casein present in cow’s milk are:

  • α S1-casein: The most abundant (40-50% of total casein). It has a primary structure rich in proline and phosphoserine residues, giving it a strong calcium-binding capacity.
  • α S2-casein: Representing around 20-25% of total casein, it is also rich in phosphoserine and interacts strongly with calcium.
  • β-casein: Constituting around 25-35% of total casein. Genetic variants of β-casein, in particular forms A1 and A2, have been the subject of specific research.
  • κ-casein: Representing around 10-15% of total casein. κ-casein plays a crucial role in stabilizing casein micelles.

These different caseins are characterized by their low solubility at the pH of milk (around 4.6), which leads to their aggregation into complex spherical structures called casein micelles. It is the colloidal calcium phosphate that helps caseins bind together, by acting like a bridge linking the casein proteins together and stabilizing the micelle structure in suspension in the milk. Colloidal calcium phosphate is essential to maintain the integrity of this structure and the functionality of the micelles.

Physiological roles

As a source of high biological quality protein, casein fulfils a number of essential physiological roles (1):

  • Source of essential amino acids: Casein contains all the essential amino acids needed for growth, repair and maintenance of body tissue. Its slow, gradual digestion ensures sustained release of amino acids into the bloodstream.
  • Mineral transport: The digestion of caseins releases smaller protein fragments called casein Phospho-peptides that binds to, and transport, minerals such as calcium and phosphorus, potentially improving their intestinal absorption (2) due to preventing the formation of insoluble calcium phosphates that are harder to absorb.
  • Satiety-enhancing effects: Due to its slower digestion compared with whey proteins, casein may contribute to a prolonged feeling of satiety, which could be beneficial in weight management (3).
  • Role in milk coagulation: κ-casein plays a crucial role in stabilizing casein micelles. The action of chymosin, an enzyme present in rennet, cleaves κ-casein, destabilizing the micelles and leading to milk coagulation, a fundamental step in the manufacture of cheese and other fermented dairy products (2).
  • Production of bioactive peptides: The enzymatic digestion of casein releases various bioactive peptides with potential biological activities, such as antihypertensive, antimicrobial or immunomodulatory effects.

Potential health effects

Although research is still ongoing, several studies suggest potential health benefits from casein consumption:

  • Support for muscle growth and recovery: Due to its slow release of amino acids, casein is often consumed after exercise or before bedtime to promote muscle protein synthesis and recovery during the night. Studies have shown its effectiveness, particularly when compared with rapidly digested proteins, in maintaining muscle mass over the long term (4,5).
  • Weight management: Casein’s ability to induce satiety could be beneficial in weight management strategies by helping to reduce overall calorie intake (3).
  • Bone health: The presence of calcium and the casein phospho-peptides that promote its absorption could contribute to bone health and the prevention of osteoporosis (7).
  • Potential antihypertensive effects: Certain casein-derived peptides have demonstrated in vitro and in vivo angiotensin-converting enzyme (ACE) inhibitory properties, suggesting a potential antihypertensive effect (8).
  • Potential immunomodulatory effects: Bioactive peptides derived from casein have shown antimicrobial activity against certain pathogenic bacteria and could influence immune function. Caseinomacropeptide derived from κ-casein has been studied for its prebiotic properties and its potential role in protecting against infections (6).

Considerations and controversies

This focus wouldn’t be complete if we did not note the existence of certain controversies concerning the consumption of casein by certain individuals:

  • Cow’s milk protein allergy: Casein is one of the main allergens in cow’s milk.
  • β-Casein A1 variant : Some studies have suggested a link between the consumption of milk containing mainly β-casein A1 variant and gastrointestinal disorders. However, these first data need further research to be confirmed (9,10).

Casein is a complex family of proteins that is abundant in milk, playing essential physiological roles as a source of amino acids, a transporter of minerals and a precursor of bioactive peptides. Its slow digestion properties and potential benefits for muscle growth, satiety and potentially bone and cardiovascular health make it a nutrient of interest. However, further research is needed to fully elucidate the mechanisms of action and long-term effects of casein consumption on human health.

References
  1. (1) de Kruif CG, Huppertz T, Urban VS, Petukhov AV. Casein micelles and their internal structure. Adv Colloid Interface Sci. 2012 Mar-Apr;171-172:36-52.
  2. (2) Liu G, Guo B, Sun S, Luo M, Liu F, Miao J, Tang J, Huang Y, Cao Y, Song M. Promoting the Calcium-Uptake Bioactivity of Casein Phosphopeptides in vitro and in vivo. Front Nutr. 2021 Aug 30;8:743791.
  3. (3) Pal S, Radavelli-Bagatini S, Hagger M, Ellis V. Comparative effects of whey and casein proteins on satiety in overweight and obese individuals: a randomized controlled trial. Eur J Clin Nutr. 2014 Sep;68(9):980-6.
  4. (4) Sumi K.,et al, Nutritional Value of Yogurt as a Protein Source: Digestibility/ Absorbability and Effects on Skeletal Muscle. Nutrients 2023, 15, 4366.
  5. (5) Pennings B, Boirie Y, Senden JM, Gijsen AP, Kuipers H, van Loon LJ. Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men. Am J Clin Nutr. 2011 May;93(5):997-1005
  6. (6) Qu Y, Park SH, Dallas DC. The Role of Bovine Kappa-Casein Glycomacropeptide in Modulating the Microbiome and Inflammatory Responses of Irritable Bowel Syndrome. Nutrients. 2023 Sep 15;15(18):3991
  7. (7) Sanjulián L, Fernández-Rico S, González-Rodríguez N, Cepeda A, Miranda JM, Fente C, Lamas A, Regal P. The Role of Dairy in Human Nutrition: Myths and Realities. Nutrients. 2025 Feb 11;17(4):646.
  8. (8) Marcone S, Belton O, Fitzgerald DJ. Milk-derived bioactive peptides and their health promoting effects: a potential role in atherosclerosis. Br J Clin Pharmacol. 2017 Jan;83(1):152-162. doi: 10.1111/bcp.13002.
  9. (9) Kay SS, Delgado S, Mittal J, Eshraghi RS, Mittal R, Eshraghi AA. Beneficial Effects of Milk Having A2 β-Casein Protein: Myth or Reality? J Nutr. 2021 May 11;151(5):1061-1072.
  10. (10) Pal S, Woodford K, Kukuljan S, Ho S. Milk Intolerance, Beta-Casein and Lactose. Nutrients. 2015 Aug 31;7(9):7285-97. doi: 10.3390/nu7095339. PMID: 26404362; PMCID: PMC4586534.
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Bone health Cardiovascular health Elderly

Dairy foods may support bone strength in older people without raising cholesterol

cholesterol falls lipids proteins senior
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Older adults aiming to maintain strength and overall health can consume dairy products without concern for adverse effects on cardiovascular health. The reassuring news comes from an Australian study of care homes, suggesting that eating more dairy foods can be an effective way to improve nutrition in older adults without raising their cholesterol levels (1).

The findings offer promising implications for caregivers and nutritionists supporting older adults, as they may help reduce the risk of falls and fractures. Given that healthcare costs for non-fatal falls were estimated at $80.0 billion in 2020, fall and fracture prevention remains essential (9).

The need for dairy food nutrition in older adults

As people age, they become more likely to experience nutritional deficiencies. Older adults living in care homes have high rates of malnutrition, including inadequate intakes of calcium and protein – increasing their risk of falls and fractures (2,3).

Correcting these deficiencies by consuming milk, yogurt, and cheese to enhance protein and calcium intake can help to reduce the rate of falls and fractures in elderly care home residents, studies have shown (4). The wide variety of textures and flavors in dairy products makes them a suitable option for older adults who experience difficulties with eating and swallowing.

However, dairy foods also contain saturated fats, which have historically been linked to high cholesterol and heart disease (5). With this in mind, researchers at the University of Melbourne in Australia sought to determine whether increasing dairy intake in older adults would worsen their cholesterol levels and overall heart health.

Assessing the impact of increased dairy food consumption

The researchers studied the effects of increased dairy food consumption over two years across 60 care homes in Victoria, Australia. These care homes were randomly divided into two groups:

  • Intervention group (30 care homes): Residents were given additional dairy foods, including milk, yogurt, and cheese, to meet recommended daily intakes.
  • Control group (30 care homes): Residents continued their usual diet without an increase in dairy consumption.

A total of 245 care home residents, with an average age of 88, participated in the study—159 in the intervention group and 86 in the control group. Dietary intake was recorded every three months, and cholesterol levels were measured at the beginning of the study and again after 12 months. The two diets were not intentionally matched for energy or nutrient content per design, but the effects of adding extra dairy portions on overall energy and nutrient intake were evaluated.

When the researchers compared the cholesterol levels of the two groups, they found reassuring results.

Eating more dairy foods increased intake of protein but not fat

Results showed that participants in the intervention group successfully increased their dairy food consumption from an average of 1.9 servings per day at the start of the study to 3.5 servings per day after 12 months. Meanwhile, participants in the control group maintained an average daily intake of around 2 dairy food servings per day throughout the study.

As an impact on the daily nutrients intakes, daily protein intake of participants in the intervention group increased by 13 grams from the start to the end of the study, while there was no significant differences in dietary intakes of total fat, saturated fat, total energy, or carbohydrates between the two groups.

Eating more dairy foods was not associated with raised cholesterol

Despite a significant difference in the elderly people’s dairy food consumption, the researchers found no significant differences in cholesterol levels between the two groups after 12 months. This remained the case when they considered whether participants had existing cardiovascular disease or were taking lipid-lowering medications. Specifically, the researchers found no differences in:

  • Low-density lipoprotein (LDL) cholesterol, often referred to as ‘bad’ because high levels can contribute to cardiovascular disease,
  • High-density lipoprotein (HDL) cholesterol, often referred to as ‘good’ because it helps remove excess cholesterol from the bloodstream,
  • Total cholesterol, the overall amount of cholesterol in the blood,
  • Triglycerides and apolipoproteins, other key markers of cardiovascular health related to lipid circulation in the blood.

Dairy foods may be a good addition to the diet of older adults

The researchers conclude that increasing dairy food intake among older people in care homes, as a strategy to reduce the risk of falls and fractures, is not associated with any changes in lipid levels. These findings suggest that olderpeople can eat more dairy foods to maintain their strength and well-being without worrying about any negative effects on their heart health.

The results could be due to several factors, say the researchers. Increased calcium intake associated with eating dairy foods may prevent fat absorption and increase lipid metabolism (6). Milk, yogurt, and cheese also contain diverse bioactive peptides and minerals, which may limit the cholesterol-raising effects of saturated fatty acids (7). Yogurt and cheese, being fermented foods, contain bacteria that may alter the gut microbiome and may improve cholesterol metabolism (8).

Whatever the reasons, for caregivers and nutritionists working with older adults, this study provides reassuring evidence that eating more dairy foods can be an effective way to improve nutrition in older adults without raising cholesterol levels or increasing the risk of heart disease, the researchers suggest.

“Among older adults in aged care homes, correcting insufficiency in the daily intake of calcium and protein using milk, yogurt and cheese does not alter serum lipid levels, suggesting that this is a suitable intervention for reducing the risk of falls and fractures.”

Iuliano S, et al., 2024

References
  1. (1) Iuliano S, Hare DL, Vogrin S, Poon S, Robbins J, French C, Seeman E. Consumption of dairy foods to achieve recommended levels for older adults has no deleterious effects on serum lipids. Nutr Metab Cardiovasc Dis. 2024 Oct;34(10):2353-2359. doi: 10.1016/j.numecd.2024.06.004. Epub 2024 Jun 13. PMID: 39003129 
  2. (2) Australian Institute of Health and Welfare. Trends in hospitalised injury due to fall in older people, 2002-03 to 2014-15. Canberra: Pointer S; 2018.
  3. (3) Iuliano S, Poon S, Wang X, Bui M, Seeman E. Dairy food supplementation may reduce malnutrition risk in institutionalised elderly. Br J Nutr 2017;117(1):142e7.
  4. (4) Iuliano S, Poon S, Robbins J, Bui M,Wang X, De Groot L, et al. Effect of dietary sources of calcium and protein on hip fractures and falls in older adults in residential care: cluster randomised controlled trial. BMJ 2021;375:n2364.
  5. (5) Hooper L, Martin N, Jimoh OF, Kirk C, Foster E, Abdelhamid AS. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev 2020;8:CD011737.
  6. (6) Lorenzen JK, Astrup A. Dairy calcium intake modifies responsiveness of fat metabolism and blood lipids to a high-fat diet. Br J Nutr 2011;105(12):1823e31
  7. (7) Weaver CM. Dairy matrix: is the whole greater than the sum of the parts? Nutr Rev 2021;79(Suppl 2):4e15.
  8. (8) Thorning TK, Bertram HC, Bonjour JP, de Groot L, Dupont D, Feeney E, et al. Whole dairy matrix or single nutrients in assessment of health effects: current evidence and knowledge gaps. Am J Clin Nutr 2017;105(5):1033e45.
  9. (9) Haddad YK, Miller GF, Kakara R, et al Healthcare spending for non-fatal falls among older adults, USA Injury Prevention 2024;30:272-276.
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21 Apr 2025
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Adult Gut Health Other studies

Can yogurt reduce the risk of colorectal cancer?

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Eating yogurt and probiotic fermented milk regularly may be associated with a reduced risk of certain colon cancers. Recent research suggests that specific colorectal tumors containing the gut bacterium Bifidobacterium occur less often among people who frequently eat yogurt compared to those who rarely consume it.

Colorectal cancer is a significant public health concern, and research is increasingly focused on understanding the factors that influence its development. Among these factors, diet and the intestinal microbiota are increasingly recognized for their crucial role in colorectal carcinogenesis (1).
According to the International Agency for Research on Cancer (IARC), the global burden of CRC is expected to increase by 60%, reaching more than 2.2 million new cases and 1.1 million deaths by 2030. In 2020, the incidence of CRC was estimated at approximately 1.9 million new cases worldwide (8).
Studying the impact of yogurt consumption on colorectal cancer risk, considering the presence of specific bacteria like Bifidobacterium in tumor tissues, offers a novel and potentially important perspective for the prevention of this disease (1).
Yogurt and fermented milks are well-known for theirs benefits to gut health. They typically contain probiotic bacteria including Bifidobacterium for some of them, which contribute to support digestion and the immune system. Scientists have long suspected that these bacteria may also play a role in preventing certain diseases, including colorectal cancer.

A recent study led by medical researchers at Harvard Medical School (Boston, USA) explored how long-term yogurt and probiotic fermented milk consumption influences the risk of colorectal cancer depending on the bacteria found in cancer tumors (1). Their findings suggest that regularly eating probiotic fermented milk might help reduce the risk of developing some colon cancers, for the subgroup of tumors characterized by the presence of Bifidobacterium.

Assessing the impact of fermented milk consumption on colorectal cancer risk

The team of researchers analyzed data from over 132 000 US men and women in two long-term health studies conducted between 1980 and 2016 (Nurse Health Study and Health Professionals Follow-up study). In these studies, dietary information about intake of dairy foods as well as other dietary and lifestyle factors was collected every 4 years using a food frequency questionnaire. The researchers grouped participants according to their average yogurt and fermented milk intake, including yogurt (<1 serving/month, 1–3 servings/month, 1 serving/week, and ≥2 servings/week).

Over time, about 2% of participants (3079 people) developed colorectal cancer, and a third of these (1121 people) had available data on the bacteria present in their tumors. Overall, 31% of colorectal cancers were Bifidobacterium-positive, and 69% were Bifidobacterium-negative. The researchers used statistical models to calculate whether there were any significant associations between yogurt intake and incidence of colorectal cancers. Here’s what they found…

The impact of eating yogurt depends on the bacteria present in colorectal cancer

While regularly eating yogurt did not appear to increase or decrease the likelihood of developing colorectal cancer, a different picture emerged when the researchers looked at Bifidobacterium-positive, and Bifidobacterium-negative colorectal cancers separately:

The association between long-term yogurt intake and risk of colorectal cancer significantly differed according to the presence or absence of Bifidobacterium in cancer tumors.

  • People who ate yogurt at least twice a week had a 20% lower risk of developing Bifidobacterium-positive colorectal cancer than those who ate less than one serving per month.
  • Eating yogurt did not appear to reduce the risk of colorectal cancer tumors that lacked Bifidobacterium.

Eating yogurt may help reduce the risk of Bifidobacterium-positive colon cancer

The researchers also investigated potential associations between long-term, regular yogurt consumption and the risk of developing colorectal cancer tumors in different locations. They looked at Bifidobacterium-positive or negative tumors that developed in the upper and lower parts of the colon or the rectum.

Results showed that:

  • Regularly eating yogurt was associated with a trend towards a lower risk of developing Bifidobacterium-positive upper colon cancer.
  • On average, people who ate yogurt at least twice a week had a 47% lower risk of developing Bifidobacterium-positive colorectal cancer than those who ate less than one serving per month.

However, no similar trends were seen for the risk of developing lower colon cancer or rectal cancer.

How might eating probiotic fermented milk help to protect us against colon cancer?

These results suggest that the possible protective benefits of eating yogurt and fermented milk on the risk of colorectal cancer might be linked to Bifidobacterium in the gut.

Previous studies have shown that yogurt and fermented milk intake is associated with a decreased risk of colorectal cancer (2). The researchers propose that the potential anti-tumor effects of fermented milk such as yogurt may be linked to its role in maintaining a healthy gut microbiome composition and barrier function (3,4,5).

Among the various bacterial strains available in fermented milks, Bifidobacterium may support gut barrier function and promote anti-tumor effects through its antioxidant, anti-inflammatory, and immune activation properties (6,7). So, eating probiotic fermented milk containing Bifidobacterium like yogurtcould contribute to strengthen the gut barrier and prevent bacteria from accessing colorectal cancer tumors.

Based on their findings, the researchers propose that Bifidobacterium in tumor tissue could reflect impaired gut barrier function, and that eating yogurt and fermented milk might help to prevent colorectal cancer with a disrupted intestinal barrier. More research is needed to confirm whether yogurt could offer protection against certain types of colorectal cancer.

Bifidobacterium is also suggested to have tumor-suppressive properties (1).

“Our findings suggest that long-term yogurt intake may lower the incidence of Bifidobacterium-positive proximal colorectal cancer (but not Bifidobacterium-negative subtype). “

Ugai S, et al., 2025

References
  1. (1) Ugai S, et al. Long-term yogurt intake and colorectal cancer incidence subclassified by Bifidobacterium abundance in tumor. Gut Microbes. 2025;17(1):2452237.
  2. (2) Sun J, et al. Higher yogurt consumption is associated with lower risk of colorectal cancer: a systematic review and meta-analysis of observational studies. Front Nutr. 2021;8:789006. 
  3. (3) Slizewska K, Markowiak-Kopec P, Slizewska W. The role of probiotics in cancer prevention. Cancers (Basel). 2020;13:13.
  4. (4) Kosumi K, et al. The amount of bifidobacterium genus in colorectal carcinoma tissue in relation to tumor characteristics and clinical outcome. Am J Pathol. 2018;188:2839–2852.
  5. (5) Taniguchi S, Shimatani Y, Fujimori M. Tumor-targeting therapy using gene-engineered anaerobic-nonpathogenic Bifidobacterium longum. Methods Mol Biol. 2016;1409:49–60. 
  6. (6) Kuru BE, Laleman I, Yalnizoglu T, Kuru L, Teughels W. The influence of a Bifidobacterium animalis Probiotic on gingival health: a randomized controlled clinical trial. J Periodontol. 2017;88:1115–1123.
  7. (7) Veettil SK, Wong TY, Loo YS, Playdon MC, Lai NM, Giovannucci EL, Chaiyakunapruk N. Role of diet in colorectal cancer incidence: umbrella review of meta-analyses of prospective observational studies. JAMA Netw Open. 2021;4:e2037341.
  8. (8) Global patterns and trends in colorectal cancer incidence and mortality – IARC
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14 Apr 2025
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Adult Q&A

Focus on vitamin B9

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B vitamins are a complex of vitamins, grouping together several organic substances. Each vitamin plays specific roles on health. This time, we will focus on vitamin B9, also known as folic acid or folate.

Vitamin B9: functions and metabolism

Folate, also known as vitamin B9, is an essential hydro-soluble vitamin that plays a critical role in various physiological processes. It is particularly important in DNA synthesis, cell division, and amino acid metabolism, making it crucial for growth, development, and overall health.

One of its primary functions is in nucleotide synthesis, where it facilitates the production of purines and pyrimidines, the building blocks of DNA and RNA. This is vital for rapidly dividing cells, such as those in the bone marrow, intestines, and developing fetus.

During pregnancy, folate is especially important for fetal neural tube development. Adequate intake helps prevent neural tube defects such as spina bifida and anencephaly. Spina bifida involves incomplete closure of the spine and spinal cord, while anencephaly is a severe condition where parts of the brain and skull fail to develop properly. This is why folic acid supplementation is widely recommended for women of childbearing age.

Folate also plays a key role in homocysteine metabolism by working with vitamins B6 and B12 to convert homocysteine into methionine, an essential amino acid. As a result, vitamin B9 helps regulate homocysteine levels. Since elevated homocysteine is linked to a higher risk of cardiovascular disease, folate is crucial for maintaining heart health.

Furthermore, folate supports red blood cell production, helping prevent megaloblastic anemia, a condition characterized by large, immature red blood cells that impair oxygen transport.

Folate and vitamin B12 share many functions in the body. They both work together to create our genetic material (DNA), form healthy red blood cells and support the normal functioning of the brain and nervous system.

Dietary Recommendations for folate

Folate is the generic name for a group of compounds. Folate is the natural form of the B9 vitamin found in foods and in the body. Folic acid is its synthetic form, used in supplements or fortified foods.

The nutritional needs of folate vary by age, sex, and physiological conditions such as pregnancy and lactation. The recommended daily intake is typically expressed as Dietary Folate Equivalents (DFE) to consider the differences in how naturally occurring folate and synthetic folic acid are absorbed by the body:

  • 1 mcg DFE = 1 mcg food folate (naturally occurring)
  • 1 mcg DFE = 0.6 mcg folic acid from fortified foods or dietary supplements consumed with foods
  • 1 mcg DFE = 0.5 mcg folic acid from dietary supplements taken on an empty stomach

The dietary reference value for healthy adults (over the age of 18) varies between 330 mcg (Europe) (2,4) and 400 mcg DFE per day (USA) (1)(depending on the local guidelines).

During pregnancy and lactation, needs can go up to 600 μg and 500 μg DFE per day:

  • Pregnant women require 600 mcg DFE/day due to the increased demand for fetal growth and neural tube development. A daily supplement of 400 mcg of folic acid is recommended before conception and during early pregnancy. However, according to a French 2021 National Perinatal Survey, less than a third of women say they started vitamin B9 supplementation before they became pregnant, even though this is recommended (3).
  • Lactating women need 500 mcg DFE/day to support infant growth and development.

Individuals with certain medical conditions (e.g., malabsorption disorders, alcoholism) may require higher folate intake or supplementation.

Dietary Sources of Vitamin B9

The sources of vitamin B9 are

  • Natural sources: Leafy green vegetables, legumes, citrus fruits, avocados, or liver (1).
  • Fortified foods: Many countries mandate folic acid fortification in cereals, flour, and pasta to prevent deficiencies (3).
  • Supplements: Often necessary for pregnant women and individuals at risk of deficiency.

Dairy products contribute to the daily intake of B9 vitamin, even if there are not considered as a major source. Milk, yogurt and cheeses may contain 5 to 12 mcg/100g of folate.

References
  1. (1) NIH, Nov 2022 – Folate – factsheet for health professionals
  2. (2) EFSA (2014) Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on Dietary Reference Values for folate, The EFSA Journal 12(11): 38
  3. (3) ANSES, Dec 2024, Fortifying flour with folic acid can help prevent neural tube malformations in newborn
  4. (4) ANSES, références nutritionnelles vitamines et minéraux
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Fermentation benefits Gut Health

How fermented dairy foods may help relieve IBS and IBD

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Eating fermented dairy foods such as yogurt may help bring relief to the millions of people who suffer from irritable bowel syndrome, inflammatory bowel disease, or other gut disorders, research suggests.

As many as 40% of people around the world suffer from symptoms of functional gastrointestinal disorders such as irritable bowel syndrome (IBS), associated with constipation, diarrhoea, bloating, and stomach pain. Most people with IBS report the triggering, or worsening of symptoms following food intake (2).  Meanwhile, gut troubles such as diarrhoea and abdominal pain are also characteristic of inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis.

These disorders can disrupt people’s daily lives and place a heavy burden on healthcare systems. However, for many people with digestive disorders, dietary choices can help manage symptoms. And it seems fermented dairy foods could have a role to play in such dietary management.

Fermented dairy foods are a source of bio-active ingredients such as beneficial gut bacteria, which have the potential to influence digestive health. A recent study led by food and health researchers at University College Dublin in Ireland explores the impact of eating bovine fermented dairy foods on gut bacteria and symptoms in people with digestive disorders (1). Their findings highlight some promising benefits but also underscore the need for further research.

Understanding the gut microbiome

The gut microbiome is a complex ecosystem of bacteria, viruses, and fungi that play a crucial role in digestion, immune function, and overall health (3,4):

  • The make-up of the gut microbiome is influenced by many factors including age, lifestyle, and genetics (3).
  • An imbalance in the make-up of the gut microbiome – such as reduced diversity, increased harmful microbes and loss of beneficial microbes – has been linked to functional gastrointestinal disorders and IBD (5,6).
  • Diet strongly influences gut microbiome composition, so understanding gut microbial responses to different foods may help in personalizing dietary recommendations to alleviate symptoms and restore the gut microbiome balance (7).

Literature search done to review the role of fermented dairy in digestive health  

The researchers reviewed studies examining the effects of eating fermented dairy on the gut microbiome and gut health in people with digestive disorders such as IBS and IBD or associated symptoms. They analysed 26 research papers including 15 clinical studies involving 1 550 participants, as well as 11 pre-clinical studies.

Most studies investigated the effects of fermented milk on the gut, while three studies examined yogurt and one examined kefir. The researchers assessed how these foods affect gut bacteria and digestive symptoms.

As a result: Eating fermented dairy foods may enhance the gut microbial characteristics

Eating fermented dairy foods may improve gut microbiome composition in people with digestive disorders. In particular, studies showed increases in gut bacteria diversity, as well as beneficial bacterial strains and short-chain fatty acids:

  • Six studies reported consistent increases in gut bacteria diversity in response to fermented dairy consumption, which is generally associated with better gut health.
  • Nine studies found that eating fermented dairy products increased levels of Lactobacillus and Bifidobacterium – bacteria known to benefit digestion and gut health.
  • Six studies showed an increase in short-chain fatty acids – compounds produced by gut microbes, which help to maintain gut and immune balance – following fermented dairy consumption, although three studies reported a decrease.

Human studies consistently report a strong trend of improved symptoms in response to fermented dairy intakes

Eating fermented dairy foods was associated with improvements in overall gut health, as well as individual symptoms. Overall, fourteen clinical studies showed improvements in gut comfort and bowel movement frequency after eating fermented dairy products:

  • Five studies found that eating fermented dairy foods helped regulate bowel movement frequency, while three studies showed improvements in stool consistency.
  • Study participants reported improvements in gastrointestinal symptoms and gut comfort across five studies, including reductions in bloating, flatulence, and diarrhoea.
  • No studies reported any deterioration in gastrointestinal disease status or symptoms in response to fermented dairy consumption.
  • These results were supported by five pre-clinical studies, which showed reduced colon damage and improved healing following fermented dairy consumption.

This review highlights that eating fermented dairy foods is a practical way to support gut health

Based on their findings, the researchers propose that eating more fermented dairy foods may be a useful way to help correct imbalances in the gut microbiome and relieve the discomfort experienced by people with digestive disorders. Not only are fermented dairy foods widely accessible, they hold the advantage of providing a broad range of essential nutrients as well as their bio-active ingredients (8) extending their health benefits beyond the scope of non-fermented dairy (9).

While these results are promising, the researchers highlight the need for further studies to help explain the mechanisms and specific components of the fermented dairy foods behind these beneficial changes observed in gut microbiome and gut symptoms.

“Fermented dairy foods can positively influence aspects of gastrointestinal health and the gut microbiome in inflammatory bowel disease and functional gastrointestinal disorders […] Increasing fermented dairy consumption is a practical dietary strategy that may aid the management of gastrointestinal complications.”

Ní Chonnacháin C, et al., 2024

References
  1. (1) Ní Chonnacháin C, Feeney EL, Gollogly C, Shields DC, Loscher CE, Cotter PD, Noronha N, Stack R, Doherty GA, Gibney ER. The effects of dairy on the gut microbiome and symptoms in gastrointestinal disease cohorts: a systematic review. Gut Microbiome (Camb). 2024 May 7;5:e5
  2. (2) Algera J, Colomier E, Simrén M. The dietary management of patients with irritable bowel syndrome: a narrative Review of the existing and emerging evidence. Nutrients. 2019;11(9):2162
  3. (3) Ogunrinola GA, Oyewale JO, Oshamika OO, Olasehinde GI. The Human Microbiome and Its Impacts on Health. Int J Microbiol. 2020 Jun 12;2020:8045646
  4. (4) Valdes AM, Walter J, Segal E, Spector TD. Role of the gut microbiota in nutrition and health. BMJ. 2018 Jun 13;361:k2179.
  5. (5) Jochum L, Stecher B. Label or Concept - What Is a Pathobiont? Trends Microbiol. 2020 Oct;28(10):789-792.
  6. (6) Holtmann GJ, Ford AC, Talley NJ. Pathophysiology of irritable bowel syndrome. Lancet Gastroenterol Hepatol. 2016 Oct;1(2):133-146.
  7. (7) Hasan N, Yang H. Factors affecting the composition of the gut microbiota, and its modulation. PeerJ. 2019 Aug 16;7:e7502.
  8. (8) Haug A, Høstmark AT, Harstad OM. Bovine milk in human nutrition--a review. Lipids Health Dis. 2007 Sep 25;6:25.
  9. (9) Leeuwendaal NK, Stanton C, O’Toole PW and Beresford TP (2022) Fermented foods, health and the gut microbiome. Nutrients 14(7), 1572
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Nutri-dense food

Experts call for dietary guidelines to reflect the protein power of dairy products  

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Dairy products are a valuable source of protein without putting pressure on the purse. But dietary guidelines may be overlooking dairy products as an affordable source of high-quality protein as well as of other essential nutrients, according to the researchers from the USA.

Current dietary guidelines for Americans categorize protein-rich foods into a designated “protein foods” group. This group includes meat, poultry, seafood, eggs, pulses, nuts, seeds, and soy products. However, one category is notably absent: dairy foods.

Results of a recent analysis conducted at the University of Washington’s Center for Public Health Nutrition suggest that dairy deserves a place in the “protein foods” group due to its high protein quality, nutrient density, and affordability (1). Researchers compared dairy with other protein group foods (2) in terms of their protein content and quality, nutrient density, and protein cost, with the following results.

Selecting protein-rich food sources: importance of portion size and protein quality

First looking at protein foods in terms of grams of protein per 100g of food, researchers found that:

  • Meat and poultry have the highest average protein content (23–27g),
  • Nuts and seeds contain 17–22g and
  • Pulses around 9g of protein.

By comparison, milk provides 3–4g of protein, while protein content is higher for other dairy foods including :

  • Greek yogurt (9g),
  • cottage cheese (10g), and
  • cheese (22g)

These values are comparable with eggs and pulses.

The article emphasizes the importance of evaluating the foods based on their serving size, rather than per 100 grams to better reflect people consumptions, and better align with dietary guidelines. The differences in protein content between dairy and protein foods reduced when protein content was calculated per serving – the amount of protein in milk (245g) or yogurt (170g) was still lower than in meat (85g) but was now in the same range as eggs, pulses, nuts and seeds.

As a second step, it is reminded that “equivalency” of proteins should consider that not all proteins are the same: some foods provide more digestible proteins than others (3,4). The researchers measured protein quality using a tool called the Protein Digestibility Corrected Amino Acid Score (PDCAAS), where foods with a higher score are more efficiently used by the body. They found that dairy proteins have a PDCAAS score of 1.0 – the highest possible rating. This means that unlike most plant proteins, dairy protein content is not affected by PDCAAS scores.

Nutrient density: a criterion to guide between different foods equivalent in protein (content and quality)

The Nutrient Rich Foods Index (NRF) assesses foods based on their make-up of nutrients to encourage and limit where necessary. Researchers used an updated version of the index where the protein (as a nutrient to encourage) is corrected according to the PDCAAS of each food, to better reflect in the score the quality of the protein.

Dairy foods present a high NRF score, providing not only high-quality protein but also several of the micronutrients to encourage (calcium, potassium, magnesium, and vitamins A and D) (5).

Results showed that, compared with other protein-rich foods, regular yogurt has the lowest energy density while highest NRF score per 100kcal of foods, after milks. making them an excellent choice for people seeking balanced nutrition without excessive calories.

Dairy foods are an affordable and accessible source of key nutrients

Sources of protein can be expensive, and studies show that high protein content is associated with high food prices, with the highest prices per 100 g of food for shellfish, lamb, fish, and beef (6). Researchers found that, according to national food prices, cost per serving was lower for dairy foods than for meat or fish.

Milk, yogurt, and cottage cheese had some of the lowest average prices per 100 g, along with eggs, pulses, and legumes. Similarly, average prices per 50g of protein were lower for low-fat and whole milk than for pork, chicken, eggs, and pulses. Given their high nutrient density, milk and other dairy foods therefore offer value for money as an affordable source of protein and key micronutrients (7).

Dairy foods deserve recognition as a protein-rich food group

Given that they compare favourably with many protein-rich foods, researchers argue that dairy foods deserve to be included in the “protein foods” group of US dietary guidelines.

Current dietary guidelines for Americans use a 1-ounce protein equivalency system (the amount of food that provides roughly 7g of protein) to compare different protein sources (8). As a conclusion of their demonstration, researchers recommend that this system should be updated to reflect protein quality rather than just quantity.

They propose that 7g of protein can be provided by the following dairy food servings:

  • Milk – 6 ounces (180 g) of whole, reduced-fat or skimmed milk
  • Yogurt – One serving of yogurt (160 g) or half serving of Greek yogurt (80 g)
  • Cheese – 1 serving of full-fat or reduced-fat cheese (30 g) or cottage cheese (76 g)

By recognising dairy as a protein-rich food, dietary recommendations could be better at reflecting its role in a achieving a healthy diet while affordable.

“Dairy foods are nutrient-rich, provide affordable high-quality protein, and compare favourably with many foods in the United States Department of Agriculture (USDA) protein foods group […] Dairy could be a part of the protein food group given its high nutrient content, amount of protein per serving, and relatively low cost.”

Drewnowski A, et al., 2025

References
  1. (1) Drewnowski A. Perspective: Milk and Dairy Provide Affordable High-Quality Protein and Merit Inclusion in the Protein Foods Group. Curr Dev Nutr. 2025 Jan;9(1):104539. doi: 10.1016/j.cdnut.2024.104539. 
  2. (2) U.S. Department of Agriculture, Agricultural Research Service, What we eat in America Food Categories for use with WWEIA, NHANES 2017 – March 2020 Prepandemic [Internet], U.S. Department of Agriculture, Agricultural Research Service, Beltsville, MD, 2022 
  3. (3) Schaafsma G, The protein digestibility–corrected amino acid score, J. Nutr. 130 (7) (2000) 1865S–1867S
  4. (4) Schaafsma G, Advantages and limitations of the protein digestibility corrected amino acid score (PDCAAS) as a method for evaluating protein quality in human diets, Br. J. Nutr. 108 (S2) (2012) S333–S336,
  5. (5) Cifelli CJ, Auestad N, Fulgoni VL, Replacing the nutrients in dairy foods with non-dairy foods will increase cost, energy intake and require large amounts of food: National Health and Nutrition Examination Survey 2011–2014, Public Health Nutr 25 (2) (2022) 332–343,
  6. (6) Drewnowski A, Adjusting for protein quality by food source may affect nutrient density metrics, Nutr, Rev. 79 (10) (2021) 1134–1144.
  7. (7) Hess JM, Cifelli CF, Agarwal S, Fulgoni VL, Comparing the cost of essential nutrients from different food sources in the American diet using NHANES 2011–2014, Nutr. J. 18 (2019) 68,.
  8. (8) U.S. Department of Agriculture. My Plate - Protein Foods.
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The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
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17 Mar 2025
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2 min read
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by YINI Editorial team
Q&A

Focus on vitamin B6

YINI Editorial team
The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
B vitamins B6 nutrient vitamin
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When we talk about B vitamins, we are actually talking about a complex of vitamins, grouping together several organic substances. While B vitamins as a whole are recognized for their effects on immunity and fatigue, each vitamin plays a specific role. This time, let’s focus on vitamin B6.

Vitamin B6: functions and metabolism

Vitamin B6 comprises a group of biologically related compounds, including pyridoxine, pyridoxal, and pyridoxamine. These compounds are metabolized into pyridoxal phosphate (PLP), the active coenzyme form, which plays a crucial role in various metabolic processes across the blood, central nervous system, and skin.

Vitamin B6 is essential for nitrogen metabolism and contributes to:

  • Amino acid metabolism, including transamination reactions, such as the conversion of tryptophan to niacin.
  • Heme and porphyrin synthesis, critical for red blood cell function.
  • Nucleic acid biosynthesis, supporting DNA and RNA production.
  • Lipid and carbohydrate metabolism, for example the involvement in glycogenolysis.

Through its metabolic functions, vitamin B6 supports:

  • Energy production, by facilitating glycogen breakdown in the liver.
  • Red blood cell synthesis and hemoglobin formation, in synergy with vitamins B9 (folate) and B12.
  • Hormonal regulation, aiding in neurotransmitter and steroid hormone activity.
  • Immune function, contributing to normal immune response.

Vitamin B6 is absorbed in the small intestine and has limited storage capacity in the body, necessitating regular dietary intake. While deficiencies are uncommon, they may lead to anemia, dermatitis, or neuropathies and often result from:

  • Protein-energy malnutrition
  • Malabsorption disorders
  • Chronic alcohol use
  • Pyridoxine-inactivating medications
  • Excessive loss during hemodialysis

Given its wide-ranging physiological importance, maintaining adequate vitamin B6 levels through diet is crucial for overall health.

Dietary Recommendations for vitamin B6

Vit B6 requirements vary across countries and diets, but the average dietary reference intake for healthy adults (over 18 years) is about 1,5 to 1,8 mg/day.

The recommended intake is lower for children (0.3 mg/d for children aged 7 to 11 months and 0.6 to 1.4 mg for those aged 1 to 14 years), and slightly higher for pregnant or breast-feeding women.

Food Sources of Vitamin B6

Dietary sources of vitamin B6 include organ meats, whole-grain cereals, fish, and legumes.

Vitamin B6 is present in both animal and plant-based foods:

  • Animal sources: Primarily organ meats (liver from beef, veal, pork, and poultry) as well as fish.
  • Plant sources: Whole-grain cereals, legumes, and starchy fruits and vegetables.

Additionally, some foods—particularly fermented dairy products—are fortified with vitamin B6.

References
  1. (1) EFSA (2016) Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on dietary Reference Values for vitamin B6. The EFSA Journal 14(6): 4485
  2. (2) ANSES, références nutritionnelles vitamines et minéraux
  3. (3) CIQUAL – Table de composition nutritionnelle des aliments. ANSES, France.
YINI Editorial team
The YINI team includes nutritionists, food engineers, registered dietitians and scientific writers.
Related Posts
Focus on the bioactive peptides in dairy and yogurt Rethinking the dietary guidelines on dairy fat and heart disease   The key to a healthier future may lie in our gut microbiome Focus on casein
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