This would seem to indicate another level of depth to the old adage 'you are what you eat'.
UPDATE 8/31: Another new study looked at the impact of diet on the viral communities in the gut. The study found that while individual communities varied substantially and remained relatively stable over time, the communities of individuals on similar diets showed convergence.
UPDATE 9/1: By pure coincidence, the seminar at work today was "Inside story: the role of gut microbes in nutrition and drug metabolism", by Peter Turnbaugh, PhD. Peter is from the FAS Center for Systems Biology at Harvard, where their research "involves the development and application of computational and experimental methods for the analysis of community structure, gene content, and function of complex microbial communities." His talk generated lots of discussion, and left me wondering whether anyone has looked at the well-studied impact of caloric restriction on longevity from the perspective of the microbiome - Google doesn't turn up much.
UPDATE 9/2: A paper published in Science yesterday surveys the enterotypes in the human gut and finds they are linked to dietary habits (high protein/saturated fat vs high carbs, etc). It also found that while some shift occurs in the span of hours following a diet change, long term dietary changes are required to change an individual's gut enterotype conclusively.
UPDATE 9/15: Peter got back to me on my question, he reports there are a couple of studies that are related to longevity and the microbiome, but nothing looking directly at whether "specific microbial consortia impact longevity." Also, researchers in Europe have opened my.microbes to the public, in case you are looking to participate in a study and are willing to spend ~$2100 to have your gut bacteria sequenced.