The role of lactate and Desulfovibrio in inflammatory bowel diseases

Elena Fajardo-Ruiz

LMU Munich, Microbiology, München [DE], elena.fajardoruiz@lmu.de

Author(s):
Elena Fajardo-Ruiz, Elisabeth Niedermeier, Barbara Stecher-Letsch, Kirsten Jung

Inflammatory bowel diseases (IBD) are chronic inflammations of the gut that represent a complex interplay between host factors and the gut microbiota. Recent studies have reported an increased colonization of the gut with Desulfovibrio species in patients with IBD, but also with Parkinson’s disease and colorectal cancer. Bacteria of the genus Desulfovibrio do not gain energy by fermentation, but by transferring electrons to sulfate, a process that leads to the release of toxic hydrogen sulfide (H₂S). Currently, it is completely unclear how Desulfovibrio proliferates and outcompetes other commensal bacteria in the gut.

Here we investigated the role of lactate, a key metabolite associated with Desulfovibrio and inflammation. Lactate is both a biomarker for disease and a preferred electron donor for Desulfovibrio. We have identified two lactate transporters in prominent Desulfovibrio strains, including D. desulfuricans and D. piger, and are currently testing their substrate specificity and mode of energization. We have used the synthetic microbial community OMM¹² to study the dynamics of Desulfovibrio populations in communities grown in the presence of lactate and pyruvate.

Our work will provide insights into the molecular mechanisms that trigger Desulfovibrio outgrowth in the gut, with the aim of identifying therapeutic targets to prevent Desulfovibrio-mediated dysbiosis.

 

Go back