We have studied by pyrosequencing the microbiota present in the bile and gall bladder mucus of healthy sows.

Bile is a biological fluid synthesized in the liver, stored and concentrated in the gall bladder interdigestively, and released into the duodenum after food intake. The microbial populations of different parts of mammal’s gastrointestinal tract (stomach, small and large intestine) have been extensively studied; however, the characterization of bile microbiota had not been tackled until now. We have studied, by pyrosequencing the microbiota present in the bile and gall bladder mucus healthy sows. Our data shows that the gall bladder ecosystem is mainly populated by members of the phyla Proteobacteria, Firmicutes and Bacteroidetes. Remarkably, two samples were dominated by single species: over 90% of the sequences obtained corresponded to Streptococcus alactolyticus or Lactobacillus salivarius. Our work has generated new knowledge of bile microbial profiles and might provide the basis for future studies on the relationship between bile microbiota, gut microbiota and health.