The very first bacteria to establish themselves in the intestine have a lasting and beneficial impact, their effectiveness in protecting us against chronic diseases, confirms this research from the University of Alberta, presented in the journal eLife. And identifying them may allow science to "adjust the microbiomes" or the balance of the unique microbial communities that live in our gastrointestinal tracts to prevent chronic disease.
These findings suggest that differences in our microbial composition likely depend on the acquisition of our first microorganisms after birth, and that the order in which they arrive in our gut also has a lasting impact on our development and health.
These microbiomes, as personal as fingerprints , are “unique in nature”: “each of us harbors a very specific microbiome – even for identical twins. Microbiomes seem to be shaped by many unknown factors, so understanding why we are all unique and different is extremely important,” comments lead author Jens Walter from the University of Alberta. Among the multiple factors that shape our microbiome, genetics, diet, environment, lifestyle and physiological state, however, according to the researchers, these factors explain less than 30% of the variation.
The first microbiome is the most persistent and influential: when researchers graft distinct microbial communities taken one by one from adult mice into the gastrointestinal tracts of genetically identical young mice, they find that the microbiome in mice adults remains closer to the initial microbiome. Even using a cocktail of four different bacteria, the researchers find that the earliest microbes are those with the strongest persistence and strongest influence on the development of the gut microbiome. This "first" microbiome is sometimes disturbed (for example, in the event of a cesarean birth or the taking of antibiotics) and this disturbance is a predisposing factor for chronic diseases.
More broadly, the goal is to understand what drives specific microbiomes in specific people to develop a much more rational approach to microbiome modification to address chronic disease.
“ We should be much more systematic. I think 30 or 40 years from now we will be able to colonize infants with specific bacteria that we will know promote health and we will be able to shape the microbiome in beneficial ways .”
