An overview of bovine beta-casomorphin-7 (b-BCM7) and its potential impact on microbiota regulation and digestive health

This review explores the global production and consumption of bovine milk, highlighting its role in human nutrition. Cow's milk production contributes to household income, food security, and provides essential nutrients (Protein 3.2 %, Fat 3,8 %, Carbohydrates 4,5 %, Calcium 0,12 %, Vitamin B6, B12, D, and C), with over 6 billion people consuming it worldwide. Milk has evolved to meet consumer needs, leading to variations such as lactose-free, skim, and fortified milk. Similarly, the differentiation between A1 and A2 milk has emerged in response to growing interest in their potential health effects. Recent research distinguishes milk based on its β-casein (β-CN) composition, particularly the A1 and A2 variants, which differ in digestion due to the release of bioactive peptides like bovine β-casomorphin-7 (b-BCM7). The amount of b-BCM7 released depends on the β-CN type, with the A1 variant linked to potential effects on the digestive, neurological, and immunological systems, potentially affecting, for example, gut motility and inflammatory responses. However, the microbiota is now recognized as a dynamic organ that contributes to bio-individuality, meaning health effects cannot be generalized. This underscores the importance of alternatives such as A2 milk, which releases less b-BCM7 and is believed to have no adverse effects. Despite concerns, milk remains a nutrient-dense superfood often discouraged in modern diets, potentially depriving people of its benefits. Further research is essential to understand the production of b-BCM7 during digestion and its health effects, clarifying whether its impact occurs during digestion and absorption or directly influences microbiota regulation, helping to provide clearer dietary recommendations.