How and When does the newborn gut microbiome begin? What constitutes an “ideal” microbiome is not yet clear: it is not simply a matter of diversity, stability or even function. This summary report (dated Sept 2013 and written by the Program Director of the Human Microbiome Project (HMP)), Lita M. Proctor, describes that the microbiome is:
- Dynamic over lifetime changing with respect to both the numbers of microbes and their membership (see below slide),
- Composed of a collection of bacteria/fungi/viruses unique to each individual,
- Unique at each region of our body as it has its own distinct community of microbes living on or in it,
- Impacted by our daily activities (bathing/washing hands/eating probiotics),
- Susceptible to disturbances resulting from use of antibiotics at sublethal dosages.
Studies have shown that our microbiota can be modified — perhaps irreversibly in some instances — by medical, dietary and hygienic practices. Infant microbial colonization is affected by delivery mode, dietary exposures, antibiotic exposure, and environmental toxicants, many of which can be eliminated or moderated.