Early life microbiome health may have lasting effect on ability to fight disease, study finds

19 Sep 2018 --- The first bacteria introduced into the gut during infanthood may have a lasting impact on an individual’s long-term ability to fight chronic disease, findings from the University of Alberta have suggested. The findings could pave the way for treatments that could adjust microbiomes in infants right after birth to help ward off serious chronic diseases. Poor gut health has been linked to obesity, Type 2 diabetes, heart disease, inflammatory bowel disease, colon cancer, neurological disorders, autism and allergies.

“Each of us harbors 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,” says Jens Walter, University of Alberta Microbial Ecologist.

“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,” says Walter.

Studies have already shown that a person's genetics, diet, environment, lifestyle and physiological state all make small contributions to the variation of the gut microbiome. But those factors account for less than 30 percent of the variation, notes Walter.

The findings demonstrate how important the moment we acquire our first microorganisms after birth is, as well as the order they arrive in for our future microbiome. Understanding how our personal microbiomes establish themselves is key to figuring out how to change them for the better.

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

The results showed that the microbiome in the adults was more similar to the microbiome introduced first. Even using a cocktail of four different bacteria, the researchers repeatedly found that the first microbes showed the highest level of persistence and the strongest influence on how the gut microbiome developed.

Future implications
The discovery about timing brings scientists one step closer to understanding how microbiomes might become disrupted – for example, through cesarean section birth or antibiotic use – which is then more likely to predispose us to chronic diseases. Ultimately, the researchers hope to find out how to address this.

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

Baby formulas fortified with probiotics already do this to a degree, but knowing more about how probiotics affect other parts of the gut's microbial community could take it to the next level.

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

Recent research, also from the University of Alberta, similarly identified the importance of the early-life microbiome for long-term health. The researchers found that commonly used household cleaners could be making children overweight by altering their gut microbiota. “Antibacterial cleaning products can change the environmental microbiome and alter risk for overweight children,” wrote the authors. “Our study provides novel information regarding the impact of these products on infant gut microbial composition and outcomes of overweight in the same population.”