Metabolic Feedback Inhibition Influences Metabolite Secretion by the Human Gut Symbiont Bacteroides thetaiotaomicron

Authors

Jennie L. Catlett, University of Nebraska-LincolnFollow
Jonathan Catazaro, University of Nebraska-LincolnFollow
Mikaela Cashman, University of Nebraska-LincolnFollow
Sean Carr, University of Nebraska-LincolnFollow
Robert Powers, University of Nebraska - LincolnFollow
Myra B. Cohen, University of Nebraska - LincolnFollow
Nicole R. Buan, University of Nebraska-LincolnFollow

ORCID IDs

https://orcid.org/0000-0002-7560-973X

Document Type

Article

Date of this Version

2020

Citation

Catlett JL, Catazaro J, Cashman M, Carr S, Powers R, Cohen MB, Buan NR. 2020. Metabolic feedback inhibition influences metabolite secretion by the human gut symbiont Bacteroides thetaiotaomicron. mSystems 5:e00252-20. https://doi.org/10.1128/mSystems.00252-20.

Comments

2020 Catlett et al.

Abstract

Microbial metabolism and trophic interactions between microbes give rise to complex multispecies communities in microbe-host systems. Bacteroides thetaiotaomicron (B. theta) is a human gut symbiont thought to play an important role in maintaining host health. Untargeted nuclear magnetic resonance metabolomics revealed B. theta secretes specific organic acids and amino acids in defined minimal medium. Physiological concentrations of acetate and formate found in the human intestinal tract were shown to cause dose-dependent changes in secretion of metabolites known to play roles in host nutrition and pathogenesis. While secretion fluxes varied, biomass yield was unchanged, suggesting feedback inhibition does not affect metabolic bioenergetics but instead redirects carbon and energy to CO2 and H2. Flux balance analysis modeling showed increased flux through CO2-producing reactions under glucose-limiting growth conditions. The metabolic dynamics observed for B. theta, a keystone symbiont organism, underscores the need for metabolic modeling to complement genomic predictions of microbial metabolism to infer mechanisms of microbemicrobe and microbe-host interactions.