Missing Microbe in Babies Raises Health Concerns
Researchers have pinpointed a “missing microbe” frequently absent in infants from Western nations, suggesting that lifestyle changes might be impacting the crucial gut bacteria necessary for health.
The decline of B. infantis emerged from a new global atlas of gut microbes. This study is part of a larger mission to grasp how the microbiome influences key health factors, including how the body defends itself against infections.
Trevor Lawley, co-senior author and researcher at the UK’s Wellcome Sanger Institute, states that this serves as a “striking example” of how modern living conditions can reconfigure the microbiome from birth. “Understanding infant microbiomes is essential as they affect a child’s growth and immune system in multiple ways,” he noted, hinting at possible implications for children’s health.
The research, which appeared in the journal Cell, involved genetically mapping over 4,000 strains of two gut bacteria in young children from 48 different countries. This breadth significantly surpasses previous studies. The findings indicated that B. infantis is notably less prevalent among babies in Europe and North America compared to counterparts in Africa and South Asia.
Interestingly, during the first two months of life, around 98.6% of infants in Europe and the US lacked B. infantis, while the absence was about 29% in South Asia and Africa. This deficiency persists in more than half of Western infants in subsequent months.
B. infantis acts as an early pioneer microbe within the gut, playing a role in food digestion and training the immune system to differentiate between beneficial bacteria and harmful pathogens. The researchers noted regional variations in its strains, such as genes associated with breaking down the millet grain fonio in West African children.
A dearth of B. infantis might impede immune system development and could shed light on the increasing prevalence of allergies and autoimmune diseases in Western nations, where the body mistakenly attacks itself.
Possible causes for the diminished presence of B. infantis could be linked to factors like increased antibiotic usage, dietary changes, and reduced exposure to environmental microbes, a consequence of improved sanitation.
Professor Alan Walker, a microbiologist specializing in gastrointestinal bacteria at the University of Aberdeen, suggested that shorter breastfeeding durations and a higher reliance on formula might contribute significantly, leading to fewer chances for bacteria to transfer from mother to child.
“There’s often a shorter period for exclusive or predominant breastfeeding in North America and Europe compared to South Asia and Africa,” Walker pointed out.
This research offers potential insights for the “bugs as drugs” approach, which involves using microbes therapeutically to prevent and treat diseases.
Interestingly, the strains of B. infantis identified in this study differed from those found in commercial probiotic products for infants. This has raised questions about the suitability of these products, typically containing gut microbes.
Yan Shao, the paper’s first author from the Wellcome Sanger Institute, criticized the infant probiotics industry for adopting a one-size-fits-all strategy. “Microbiomes are complex, unique ecosystems, but they’ve been treating all babies the same by using the same bacterial ‘seeds’ worldwide,” he stated.
The findings highlight the importance of “local ecological and cultural contexts” in shaping infant microbiome development, indicating the need for “tailored probiotic strategies,” according to Cristina Menni, a senior lecturer in molecular epidemiology at King’s College London.
