The human intestinal microbiota is a complex and dynamic consortium of microbes that is crucial for human health and disease prevention. Our lab has been studying the abundant bacterial members of this ecosystem to understand how they interact with each other both cooperatively and antagonistically to form these health-promoting communities. We use basic microbiological, genetic, biochemical, and gnotobiotic mouse analyses, combined with genomic, metagenomic and computational analyses to understand these complex interactions. We have discovered numerous classes of new antimicrobial proteins that these bacteria use to compete in their ecosystem, and we are studying their mechanisms of action, ecological properties, and how we may translate these molecules for human health benefits. Another focus of the lab is the evolution of microbes in the human gut and how genetic elements horizontally transferred between bacterial species personalize each individual’s gut microbiota and the phenotypes and community benefits conferred by these shared genetic elements.
Brigham and Women's Hospital / Harvard Medical School
Boston, MA
Postdoctoral Fellowship - Bacteroides fragilis genetics
1996
University of Maryland Medical Center / Center for Vaccine Development
Baltimore, MD
Postdoctoral Fellowship - Vibrio cholerae pathogenesis
1995
Wake Forest University Medical Center / Bowman Gray School of Medicine
Winston-Salem, NC
PhD - Microbiology and Immunology
1991
Rensselaer Polytechnic Institute
Troy, NY
BS - Biology
1987
Distribution of luxS and production of autoinducer-2 among gut Bacteroidales.
Distribution of luxS and production of autoinducer-2 among gut Bacteroidales. bioRxiv. 2026 Jul 27.
PMID: 42619800
High-throughput analyses of Phocaeicola vulgatus reveal fitness determinants for gut colonization and during colitis.
High-throughput analyses of Phocaeicola vulgatus reveal fitness determinants for gut colonization and during colitis. Gut Microbes. 2026 Dec 31; 18(1):2661410.
PMID: 42026761
Antagonism by the type VI secretion system of Bacteroides fragilis is controlled by a TetR family regulator and released small molecule.
Antagonism by the type VI secretion system of Bacteroides fragilis is controlled by a TetR family regulator and released small molecule. Proc Natl Acad Sci U S A. 2026 Apr 14; 123(15):e2516485123.
PMID: 41945450
Discovery of a secreted Bacteroides fragilis mucinase that cleaves mucins with bis-T O-glycans through a carbohydrate binding module-dependent mechanism.
Discovery of a secreted Bacteroides fragilis mucinase that cleaves mucins with bis-T O-glycans through a carbohydrate binding module-dependent mechanism. Gut Microbes. 2026 Dec 31; 18(1):2644983.
PMID: 41856961
Phosphorothioate DNA modification by BREX type 4 systems in the human gut microbiome.
Phosphorothioate DNA modification by BREX type 4 systems in the human gut microbiome. Nat Commun. 2026 Jan 22; 17(1):1717.
PMID: 41571653
Lessons from the model gut Bacteroidales Bacteroides fragilis and Bacteroides thetaiotaomicron and future opportunities.
Lessons from the model gut Bacteroidales Bacteroides fragilis and Bacteroides thetaiotaomicron and future opportunities. J Bacteriol. 2025 11 20; 207(11):e0034625.
PMID: 41099497
DNA-utilization loci enable exogenous DNA metabolism in gut Bacteroidales.
DNA-utilization loci enable exogenous DNA metabolism in gut Bacteroidales. Proc Natl Acad Sci U S A. 2025 Sep 23; 122(38):e2505388122.
PMID: 40956896
Antagonism by the Type VI secretion system of Bacteroides fragilis is controlled by a TetR family regulator and released small molecule.
Antagonism by the Type VI secretion system of Bacteroides fragilis is controlled by a TetR family regulator and released small molecule. bioRxiv. 2025 Aug 20.
PMID: 40894554
Bacteroides expand the functional versatility of a conserved transcription factor and transcribed DNA to program capsule diversity.
Bacteroides expand the functional versatility of a conserved transcription factor and transcribed DNA to program capsule diversity. Nat Commun. 2024 12 30; 15(1):10862.
PMID: 39738018
A ubiquitous mobile genetic element changes the antagonistic weaponry of a human gut symbiont.
A ubiquitous mobile genetic element changes the antagonistic weaponry of a human gut symbiont. Science. 2024 10 25; 386(6720):414-420.
PMID: 39446952