Our laboratory studies interbacterial interactions among colonic commensals. Altered composition of the gut microbiome contributes to many disease states, and targeted manipulation holds therapeutic promise. The intestinal microbiome is a complex ecosystem where bacteria occupy overlapping niches. Bacteria contact one another, eliciting responses which may neutral, competitive, or collaborative. Bacteroidetes comprise one of the dominant phyla in the human gut microbiome and are known to compete with diverse species to colonize and persist in the intestine. As part of their fitness for the colonic environment, Bacteroidetes utilize a remarkable diversity of carbon sources, and some encode type VI secretion systems which deliver effectors (toxins) to kill contacting bacteria. Genomes of these Bacteroidetes also encode immunity proteins which prevent intoxication of self and kin.

Current projects in our lab include:

1. Discovery and characterization of interbacterial responses among Bacteroidetes.
2. Elucidating mechanisms and physiologic importance of antagonism mediated by type VI secretion systems.
3. Determining how contact among Bacteroides species impacts polysaccharide utilization.
4. Determining how bacteria contribute to colorectal cancer incidence, progression, and metastasis by microbiome profiling from formalin fixed paraffin embedded tissue.
5. Characterizing and targeting G protein signaling pathways in the parasite Naegleria fowleri.

To address these aims, we employ a variety of approaches, including proteomics, next generation sequencing, bacterial genetics, biochemistry, structural biology, and mouse models of intestinal colonization.