The goal of the proposed research is to identify molecular metabolic signals of microbial syntrophy in the human gut, with the long-term goal of developing a predictive model relating host diet to healthy gut microbiota resiliency. Specifically, the research in the project leader's laboratory aims to identify and characterize the physiological function of metabolites and genes produced by human symbiotes Bacteroides thetaiotaomicron (B. theta), a bacterium, and Methanobrevibacter smithii (M. smithii), a methane-producing archaeon, in a novel co-culture system. B. theta and M. smithii are the dominant bacterium and archaeon in the human gut, respectively; their metabolisms are interdependent; and both are known to associate with gut epithelia. Perturbation of Bacteroides and/or Methanobrevibacter populations is associated with obesity, anorexia, irritable bowel disease, Crohn's disease, colorectal cancer, and diverticulosis. For these reasons, the project leader hypothesizes that metabolic syntrophy between both organisms is essential for healthy gut function and diet or pathogen challenge disrupts syntrophy, leading to digestive disorders and infectious disease.
Three specific aims are proposed to test this hypothesis using a novel co-culture system.
In Specific Aim 1, the project leader will optimize a B. theta/M. smithii co-culture system. Specifically, she will use anaerobic microbiology techniques to define the nutritional requirements of a syntrophic continuous co-culture in a chemostat and test nutritional enhancements under conditions encountered in the human gut. She will also use optical and confocal fluorescence microscopy to study the spatial organization (planktonic or associated in aggregates) of both organisms in co-culture.
In Specific Aim 2, the project leader will create an integrated metabolic model of co-culture syntrophy based on metabolomic and transcriptomic data. Specifically, she will use next-generation sequencing technology (RNAseq) to identify gene transcripts upregulated by both organisms in syntrophic co-culture to improve accuracy of the metabolic system models. The system model will be validated with global and targeted metabolomics data. The refined system model, integrating transcriptomic and metabolomics datasets, will be used to predict how pathogen challenge affects syntrophic B.theta/M.smithii metabolism. Finally, in Specific Aim 3, the project leader will test co-culture resiliency to pathogen challenge. She will measure the metabolic and transcriptional changes that occur in the co-culture system when challenged by the mouse gut pathogen enterohemorrhagic Citrobacter rodentium. These experiments will be used to further refine and test the system model generated in Specific Aim 2. The innovative outcome of this research will be the demonstration that B. theta and M. smithiii in co-culture communicate through the two-way exchange of small molecule metabolites. Addition of a pathogen is expected to disrupt this communication system. This work is highly significant in that it will demonstrate syntrophy between common gut microbes that contribute to human health and disease.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Exploratory Grants (P20)
Project #
Application #
Study Section
Special Emphasis Panel (ZGM1)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Nebraska Lincoln
United States
Zip Code
Yang, Yongliang; Yu, Jing; Monemian Esfahani, Amir et al. (2018) Single-cell membrane drug delivery using porous pen nanodeposition. Nanoscale 10:12704-12712
Lai, Rui; Dodds, Eric D; Li, Hui (2018) Molecular dynamics simulation of ion mobility in gases. J Chem Phys 148:064109
Casey, Carol A; Thomes, Paul; Manca, Sonia et al. (2018) Giantin Is Required for Post-Alcohol Recovery of Golgi in Liver Cells. Biomolecules 8:
Gardner, Stewart G; Marshall, Darrell D; Daum, Robert S et al. (2018) Metabolic Mitigation of Staphylococcus aureus Vancomycin Intermediate-Level Susceptibility. Antimicrob Agents Chemother 62:
Yang, Ruiguo; Broussard, Joshua A; Green, Kathleen J et al. (2018) Techniques to stimulate and interrogate cell-cell adhesion mechanics. Extreme Mech Lett 20:125-139
Catazaro, Jonathan; Andrews, Tessa; Milkovic, Nicole M et al. (2018) 15N CEST data and traditional model-free analysis capture fast internal dynamics of DJ-1. Anal Biochem 542:24-28
Wang, Yuan; Singh, Nishant K; Spear, Timothy T et al. (2017) How an alloreactive T-cell receptor achieves peptide and MHC specificity. Proc Natl Acad Sci U S A 114:E4792-E4801
Gomes-Neto, João Carlos; Kittana, Hatem; Mantz, Sara et al. (2017) A gut pathobiont synergizes with the microbiota to instigate inflammatory disease marked by immunoreactivity against other symbionts but not itself. Sci Rep 7:17707
Shang, Xin; Lai, Rui; Song, Xi et al. (2017) Improved Photoinduced Fluorogenic Alkene-Tetrazole Reaction for Protein Labeling. Bioconjug Chem 28:2859-2864
Rose, Jordan; Brian, Christian; Woods, Jade et al. (2017) Mitochondrial dysfunction in glial cells: Implications for neuronal homeostasis and survival. Toxicology 391:109-115

Showing the most recent 10 out of 17 publications