A10: Navigation abilities of gut commensals and their modulation in the gut-liver axis
In the healthy gut, the mucus layer separates microbes from the host, and the swimming motility of commensals is quenched. An entire toll-like receptor system (TLR-5) is dedicated to detecting flagellins, the monomeric component of the bacterial flagellum, powering swimming motility. High levels of flagellins have been linked to dysbiotic conditions, often accompanied by altered mucus barrier and increased bacterial translocation, which are hallmarks of diseases in the gut-liver axis.
However, despite their suggested importance in health and disease, gut commensals’ swimming abilities have mostly been addressed indirectly.
Project A10 aims at observing directly the motility and chemotaxis (altogether termed navigation abilities) of gut commensals, using biophysical methods and explore their impact and modulation within the gut-liver axis.
We more specifically aim to:
(1) interrogate the diversity of motility modes of human gut commensal bacteria, by screening an established human strain collection (from Q02 project), and compile a subset of model motile commensals.
(2) test in selected strains the direct effect of two major gut-liver mediators, secretory IgA and bile acids, in collaboration with B06 and A07.
(3) explore bacterial navigation in health versus diseased states, focusing on faecal samples or ascitic fluids in the context of spontaneous bacterial peritonitis, in collaboration with B07 and B09.