Impact of Milk Derived β-Casomorphins on Physiological Functions and Trends in Research: A Review

Abstract

β-Casomorphins are a group of opioid peptides released during gastrointestinal digestion or food processing from the β-casein of milk protein. Consequently, milk can be divided into A1 and A2 "like" groups depending upon the presence or absence of proline or histidine at the 67th position of β-casein. A1 "like" milk is postulated to be a source of BCM-7 as histidine allows the cleavage at this position, while A2 "like" milk has proline that resists the hydrolysis. On one hand, BCM-7 has been implicated as a risk factor for cardiovascular diseases, type I diabetes, and neurological disorders. On the other hand, various physiological effects of these peptides have also been documented, i.e., secretion of mucus, increased activity of superoxide dismutase and catalase, increased levels of prolactin, and analgesic role. In addition, many evidences correlate these peptides with various immunological functions, such as development of innate immunity, lymphocyte proliferation and cellular immunity, role in autoimmune diseases, histamine release, and allergy. In conclusion, the role of β-casomorphins in physiological functions remains controversial and more research with improved diagnostic techniques is needed to unravel the mechanism and study physiological functions of β-casomorphins. Thus, health-related aspects of β-casomorphins (positive, negative, and immunological impacts) have been comprehensively reviewed in this article.

The effects of dairy and dairy derivatives on the gut microbiota: a systematic literature review

“…36,67,68 However, we speculate that dairy products may influence the gut microbiota via mechanistic pathways such as: (1) facilitating the growth of beneficial strains, 69 (2) suppressing the growth of pathogenic strains, 70 and (3) altering the gastrointestinal (GI) environment ( Figure 2). 33,71,72…”

“…81,82 Altering the gastrointestinal environment Dairy components, in particular milk proteins and fats, are capable of changing the luminal environment and thereby instigating changes to the gut microbiota composition. 33,71,72 The A1 beta-casein protein fraction in dairy has shown to alter the GI transit time and trigger GI inflammation by producing opioid peptides, which in turn may influence the gut microbiota composition. [83][84][85] Although evidence do exist to show the potential of A1 beta-casein to increase GI transit time and trigger inflammation, the subsequent impact of these events on the gut microbiota has not been studied yet in both animal and human studies.…”

Simultaneous Determination of Nitrite and Nitrate in Milk Samples by Ion Chromatography Method and Estimation of Dietary Intake

“…[12] Milk is often regarded as being nature's most complete food consumed by humans. [13] Although, a variety of naturally bioactive peptides have been found in milk which exert a number of health beneficial activities such as boosting natural immune system and reducing the risk of chronic diseases via the a great impact on major body systems including digestive, nervous, endocrine, cardiovascular, and diabetes, [14,15] but, it is easily exposed with large number of physical pollutants (foreign bodies, radionuclides), chemicals (pesticides, heavy metals, antibiotics, nitrates, and so) and caused undesirable health effects. [16,17] Previous studies confirm that nitrates and nitrites are frequent constituents of many foods including vegetables, fresh and cured meats, dairy products, fruits, and grains.…”

Caseins as Regulators of Hematopoiesis

“…A2 β-casein is predominantly found in the milk of Channel Island cows, Guernsey and Jersey cows, Southern French breeds, Charolais and Limousin cows [25], and Zebu original cattle of Africa. The presence of proline or histidine at the 67th position of β-casein is associated with a major effect in terms of bioactive peptide release by different gastrointestinal enzymes [26]; thus, a bioactive seven-amino-acid peptide, β-casomorphin-7 (BCM-7), can be more easily released in the small intestine by digestion of A1 β-casein with pepsin, leucine aminopeptidase, and elastase, but the alternative proline at position 67 prevents a cleavage at this site [27].…”