Microbiota-Derived Metabolites and Bacterial Energetics

Microbial metabolites in the GI tract play a key role in the regulation of bacterial colonization and pathogenesis. Among the important microbiota metabolites is indole, which is well known for regulating bacterial motility, stress responses, biofilm formation, antibiotic resistance and virulence. Our recent work is consistent with the notion that indole segregates cells spatially to repel invaders while recruiting beneficial resident bacteria to growing microbial communities within the GI tract [1]. However, the mechanisms by which indole and other metabolites mediate homeostasis in the microbial community are unclear. I will discuss our latest results that implicate indole in the self-regulation of bacterial energetics. Measurements that show a reduction in the cell membrane potential due to indole will be interpreted in terms of the modifications of enzymatic activity in select protein complexes. I will present our model for how E. coli might sense and respond to the dissipation of its potential, based on single molecule measurements of fluorescent proteins. I will conclude with discussions on the potential effects of energetic regulation by metabolites on the colonization potential in bacterial niches.

References

[1] Yang J., Chawla R, Rhee KY., Gupta R., Manson MD, Jayaraman A, and Lele P.P, Proc. Natl. Acad Sci USA, 2020