From a study on the effect of coffee consumption on gut flora:
The impact of a moderate consumption of an instant coffee on the general composition of the human intestinal bacterial population was assessed in this study. Sixteen (16) healthy adult volunteers consumed a daily dose of 3 cups of coffee during 3 weeks. Faecal samples were collected before and after the consumption of coffee, and the impact of the ingestion of the product on the intestinal bacteria as well as the quantification of specific bacterial groups was assessed using nucleic acid-based methods. Although faecal profiles of the dominant microbiota were not significantly affected after the consumption of the coffee (Dice's similarity index = 92%, n = 16), the population of Bifidobacterium spp. increased after the 3-week test period (P = 0.02). Moreover, in some subjects, there was a specific increase in the metabolic activity of Bifidobacterium spp. Our results show that the consumption of the coffee preparation resulting from water co-extraction of green and roasted coffee beans produce an increase in the metabolic activity and/or numbers of the Bifidobacterium spp. population, a bacterial group of reputed beneficial effects, without major impact on the dominant microbiota
I did a paleohacks search on coffee and gut flora, but the subject doesn't appear to have been discussed.
What are your thoughts, does coffee have a beneficial impact on gut flora, especially the beneficial bifidobacterium spp.?
The link between coffee and its beneficial effects on T2DM, etc. still seems to be an open book. Perhaps gut flora is one of the missing links?