Western infants missing key gut microbe linked to health risks

A global atlas of gut bacteria shows that B. infantis, a microbe important for digesting foods and training the immune system, is largely absent in Western babies—about 98.6% lack it in the first two months in Europe and the US, versus ~29% in South Asia and Africa. The absence persists in many Western infants and could hinder immune development, potentially helping explain rising allergies and autoimmune diseases. Researchers suggest lifestyle factors such as antibiotic use, dietary shifts, reduced environmental exposure, and shorter or less exclusive breastfeeding may limit transfer of B. infantis from mother to child. The finding also questions the suitability of some commercial probiotic products, as they may not reflect regional strains, underscoring a need for tailored probiotic strategies and further study of microbiome-health links.