Antivirulence activity of the human gut metabolome.
Bottom Line: Importance: Microbes can communicate through the production and sensing of small molecules.Within the complex ecosystem formed by commensal microbes living in and on the human body, it is likely that these molecular messages are used extensively during the interactions between different microbial species as well as with host cells.Deciphering such a molecular dialect will be fundamental to our understanding of host-microbe interactions in health and disease and may prove useful for the design of new therapeutic strategies that target these mechanisms of communication.
Affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.Show MeSH
Related in: MedlinePlus
Mentions: Although our results strongly suggested that the intestinal microbiota is involved in the production of the inhibitor of Salmonella invasion gene expression, it was still possible that the bioactive compounds were produced by host cells in response to the intestinal microbiota. In order to determine if this was the case or if the activity was independent of host factors, we set out to try to reproduce the inhibitory activity of the fecal extracts using gut microbes grown in the laboratory. To do so, we used an anaerobic, continuous-culture chemostat system to grow microbial communities from the intestinal tracts of three healthy human donors. Culture medium was inoculated with fresh fecal samples, and the communities were allowed to develop and stabilize for several weeks. The effluents from each of these laboratory-grown microbial communities were collected and extracted with ethyl acetate, as described previously. The extracts were then tested against Salmonella to determine their effect on hilA expression during late logarithmic growth. Figure 6 shows that extracts from the three microbial communities used caused significant repression of hilA expression, establishing that the intestinal microbiota is indeed responsible for production of the biological activity, independently of host factors.
Affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.