Bifidobacterium infantis: For infants only?
The name of this microbe, Bifidobacterium infantis, could cause you to think that it is relevant only to the health of infants. But that’s not true.
B infantis has indeed been shown to be a key player in the microbiome of infants (that I discuss in detail in my Super Gut book). This microbe allows children who are breastfed to digest human milk oligosaccharides, HMOs, of breast milk—HMOs are indigestible without this and related microbes. If B infantis is not passed on from mother to child during birth or breastfeeding because mom lost it due to, say, prior courses of antibiotics and other microbiome-disruptive factors, then the child is unable to properly metabolize HMOs. Unmetabolized HMOs lead to more frequent and poorly-formed bowel movements, more colic and thereby discomfort for the child, and impaired neurological development. Restoration of B infantis yields dramatic health benefits that include greater likelihood of sleeping through the night, half as many bowel movements (and thereby diaper changes for mom and dad), less diaper rash and, as an older child, less asthma, less irritable bowel syndrome symptoms, less likelihood of becoming obese, and have higher IQs. In short, having B infantis during infancy yields lifelong advantages.
But what about B infantis in the adult microbiome? Does this species play a role in adult health, also?
Like L reuteri, nearly all adults have lost B infantis likely due to reasons that include antibiotics and other prescription drugs, over-the-counter drugs, food preservatives, emulsifying agents, chlorinated drinking water, glyphosate and other herbicides, pesticides, and others. Few adults in the modern world therefore retain these important microbes even if they were passed onto them by their mothers.
Emerging science is telling us that restoring various strains of this microbe yields some important effects in adults. Among the documented benefits of restoring B infantis are:
- Reduction of inflammatory markers such as C-reactive protein, IL-6, and TNF-alpha in people with ulcerative colitis, chronic fatigue syndrome, and psoriasis (35624 strain)
- Reduced symptoms of celiac disease in people who experience continued symptoms despite following a gluten-free diet (NLS-SS strain)
- Reduction of symptoms of irritable bowel syndrome (IBS) and associated mental distress (M-63 strain, perhaps 35624)) (although combination with other species may be necessary)
- In preliminary experience, B infantis (ATCC 15697) stimulated a major step in the immune pathway (Treg cells that govern much of the human immune response), a feature shared by few other microbial species.
- It is likely a major player in the group of beneficial microbes that may protect against upper respiratory viral infections (multiple strains).
- B infantis is a producer of folate (multiple strains).
While taking up long-term residence (“engraftment”) does occur with B infantis in babies (up to one year documented so far), restore B infantis in adults and it takes up residence only temporarily, gone within two weeks of consumption. We now have evidence, however, that when combined with HMOs, B infantis can take up longer-term residence in adults. Can restoration of B infantis coupled with increased intake of non-breastmilk HMOs and other prebiotics provide benefits that are greater than that associated with B infantis alone? Anecdotally, I am hearing about some interesting effects of doing so. Given the emergence of HMO prebiotic fibers becoming commercially available, such as that from Layer Origin Nutrition, we may be able to increase the effectiveness of some probiotic strategies. So stay tuned.