The community within..

For awhile I have been thinking about the importance of the gut community composition. Reasearch indicates that there's not much that we can do to change the identity of our gut microbes. Even probiotics - their effects are entirely transitory: they are residents while we take them, but seem unable to establish permanent residency. It seems one's microbes are pretty much set from birth.

This led me to think about how the location of one's birth might be very important in determining our intestinal flora. And perhaps the biogeographic differences in human health (the longevity of certain cultures, the lack of heart disease in others) may be attributed to the differences in gut flora: these people had the good chance of being born where particularly beneficial microbes are found (This could even generate a new industry: select where you want to deliver based on what traits are present in that environment...)


Really though, all this pondering speaks to one of the biggest, unresolved issues in microbial ecology: how to realte identity with function? Microbial communities are hyperdiverse, and while it is possible to inventory members, and to inventory processes...it is very hard to figure out which microbe is performing which function.

So today I received my journal alerts for this week, and in the new Nature I found this:

"A core gut microbiome in obese and lean twins" (Turnbaugh et al. 2009)

The results reveal that the human gut microbiome is shared among family members, but that each person’s gut microbial community varies in the specific bacterial lineages present....

Obesity is associated with phylum-level changes in the microbiota, reduced bacterial diversity and altered representation of bacterial genes and metabolic pathways. These results demonstrate that a diversity of organismal assemblages can nonetheless yield a core microbiome at a functional level, and that deviations from this core are associated with different physiological states (obese compared with lean).

If something like obesity can be related to compositional changes in our gut flora - what else? Are so many of the things we think are congenital, envriomnental, behavioural, the product of our gut flora?


I think I need a new community. But how?