Scientists at Morinaga Milk Industry Co., Ltd. have long theorized that Human-Residential Bifidobacteria (HRB) are superior to non-Human-Residential Bifidobacteria (non-HRB) in promoting good health outcomes.
The results of a new study strengthen the evidence for this theory, showing that infant-type HRB may be able to break down incompletely digested peptides in the infants’ gastrointestinal systems and thus contribute to their overall health.
Human-Residential Bifidobacteria for Humans
Morinaga Milk has been conducting research on bifidobacteria for many years, and studies over the past decades have shown that bifidobacteria play a vital role in various aspects of human health. There are two major groups of bifidobacteria: Human-Residential Bifidobacteria, which naturally reside in the human intestines, especially in infants, and non-Human-Residential Bifidobacteria, which are natural inhabitants of animals or the environment.
Research on the physiological properties that differentiate HRB and non-HRB species has made it clear that HRB are particularly effective at utilizing the human milk oligosaccharides (HMOs) in breast milk and are highly tolerant to lysozyme, a natural antibacterial factor present in human body. These characteristics allow HRB species to effectively colonize the infant gut, thereby contributing to the development and maturation of a healthy microbiome. Based on these findings, Morinaga Milk believes that HRB are beneficial, natural, and suitable for consumption by infants.
Opioid Peptides and Infant Health
Opioid peptides are peptides that bind to opioid receptors in the brain and can influence the release of neurotransmitters. Some opioid peptides are manufactured by the body, but others come from food. Incomplete digestion of proteins found in milk and cereals can create food-derived opioid peptides in the intestines. In healthy people, these peptides are hydrolyzed (or broken down) by enzymes and cause no harm. However, in the case of people with dysbiosis (impaired microbiota) or leaky gut, opioid peptides can cross the intestinal and blood-brain barriers, ultimately affecting the opioid and central nervous systems (Fig. 1). There is strong evidence that food-derived opioid peptides may cause serious diseases in sensitive people, such as those with mental disorders (Sokolovet al., 2014) and celiac disease (Hardy and Tye-Din, 2016, Kumar et al., 2017).
Because infants have an underdeveloped intestinal barrier, food-derived opioid peptides are more likely to cross into their brains. Consequently, infants with their immature central nervous systems are more susceptible to health disorders associated with opioid peptides, such as sudden infant death syndrome, atopic dermatitis, and autism. Considering these facts, Morinaga Milk conducted a study focused on the relationship between opioid peptides and infant health — specifically whether bifidobacteria can break down potentially harmful food-derived opioid peptides.
Degradation of food-derived opioid peptide
Morinaga Milk tested the ability of 18 strains of bifidobacteria, including both HRB and non-HRB, to degrade three different types of food-derived opioid peptides: beta-casomorphin-7 (BCM-7) from human milk, BCM-7 from bovine milk, and gliadorphin-7 (GD-7) from wheat gluten. Various strains of infant-type HRB proved capable of degrading food-derived opioid peptides much more effectively than strains of HRB more commonly found in adults or non-HRBs (Fig. 2). Several kinds of peptides were 100 percent hydrolyzed by infant-type HRB, while adult HRB and non-HRB never exceeded 15 percent hydrolyzation. This finding indicates the potentially crucial role of infant-type HRB in the intestines of infants to eliminate food-derived opioid peptides. The exact mechanisms of action by which infant-type HRB eliminate food-derived opioid peptides remain unclear, so more research is needed to better understand the ultimate impact of bifidobacteria on infant development. Morinaga Milk will continue to investigate the functional health benefits of HRB in humans.
About Bifidobacteriuminfantis M-63
Bifidobacteriuminfantis M-63 (MCC1872), which was proved capable of effectively degrading food-derived opioid peptides, is one of the best-studied HRB strains by Morinaga Milk. It is highly capable of utilizing human milk oligosaccharide in breast milk. M-63 is considered highly adapted to the intestinal environment of humans, especially infants. The results of an in vitro study show that M-63 prevented the growth of rotavirus. In addition, its efficacy for improving irritable bowel syndrome has also been substantiated in clinical studies.