Infant microbiome: First gut bacteria may have ‘lasting impact’ on risk of chronic diseases

The findings, reported in eLife​, show that the first bacteria introduced into the gut have a lasting impact on the shape of our microbiome and may impact the risk of chronic conditions and disease states.

Led by Jens Walter from the University of Alberta, the team noted that recent studies have linked poor gut health has been to a raft of metabolic conditions, lifestyle diseases, and other conditions, including; obesity, Type 2 diabetes, heart disease, inflammatory bowel disease, colon cancer, neurological disorders, autism and allergies.

According to Walter, the findings from the new study could eventually mean doctors and healthcare professionals are able to establish beneficial gut bacteria in infants right after birth.

"Each of us harbours a microbiome that is vastly distinct, even for identical twins. Microbiomes are important for our health, but they appear to be shaped by many unknown factors, so it's hugely important to understand why we are all different," he said.

Timing is key​

In the study, Walter and his team introduced distinct microbial communities, collected one at a time from adult mice, into the gastrointestinal tracts of young, genetically identical mice.

Results showed that as the mice grew into adults, their adult microbiome was more similar to the microbiome introduced first.

Even using a cocktail of four different bacteria, the team repeatedly found that the first microbes showed the highest level of persistence and the strongest influence on how the gut microbiome developed, noted the authors.

According to Walter, this discovery regarding the timing of microbial population brings scientists one step closer to understanding how microbiomes might become disrupted –for example, through caesarean section birth or antibiotic use – which is then more likely to predispose us to chronic diseases, and how to potentially address that.

"If we know what drives specific microbiomes in specific people, we can have a much more rational approach to potentially altering the microbiome, and developing strategies to address those diseases," he commented.

"Having long-term persistence of microbes when they colonise in the gut early in life means that a health-promoting biome could potentially be established by introducing beneficial bacteria straight after birth,” he said.

The researcher noted that while infant and baby formulas fortified with probiotics already do this to some degree, knowing more about how probiotics affect other members of the gut's microbial community could take it to the next level.

"We could be a lot more systematic,” he suggested. “I think in 30 or 40 years we'll be able to colonise infants with specific bacteria we know are health-promoting and shape the microbiome in a beneficial way."

Source: eLife​
Published online ahead of print, doi: 10.7554/eLife.36521​
“Experimental evaluation of the importance of colonization history in early-life gut microbiota assembly”​
Authors: Inés Martínez, et al​