St. Louis Team Probes Gut Bacteria Infections
A nearly $11 million federal grant funds early research that could eventually guide gentler treatments for C. diff and urinary infections.
Updated on Nov. 2, 2026 in Life Sciences
Washington University School of Medicine in St. Louis has received a nearly $11 million federal grant from the National Institute of Allergy and Infectious Diseases to study how gut bacteria such as C. diff and E. coli shift from harmless to infection-causing. The project, led by Dr. Gautam Dantas, is research-stage and draws on collaboration with Northwestern University.
Why it matters
Researchers are trying to explain why some gut bacteria cause infections while others remain harmless, a question that matters because antibiotics that treat one infection can also wipe out beneficial microbes and allow harmful bacteria to multiply.
The grant builds on a stool-sample collection of more than 30,000 samples gathered over 15 years, far larger than the 2,756 samples from 729 children analyzed in a 2023 PLOS Biology study. The research has not yet reported findings, so the mechanisms that separate harmful from harmless gut bacteria remain unidentified.
The players
Washington University School of Medicine
A St. Louis medical school whose research spans genomics and infectious disease, leading the federal grant project.
Dr. Gautam Dantas
A WashU professor of laboratory and genomic medicine who leads the project studying gut bacteria.
Northwestern University
A research university serving as a partner institution in the federally funded gut bacteria project.
National Institute of Allergy and Infectious Diseases
The federal agency within the National Institutes of Health that funds the nearly $11 million grant.
The details
The project will compare stool samples from patients with C. diff infections, people carrying C. diff without detectable toxins, and other hospital patients. A separate effort will examine stool and urine samples collected over six months from mostly female patients with recurring urinary tract infections. Gut microbiome — the community of trillions of microbes living in the intestines — is central to the work, since antibiotics can clear a urinary infection while also disrupting these beneficial bacteria.
Timeline
Stool samples used in the collection were gathered over the past 15 years.
Stool and urine samples from recurring UTI patients will be collected over the next six months.
The Tech Race
The project joins a growing body of microbiome research that uses large stool-sample archives and genomic methods to map gut bacteria. The 2023 PLOS Biology analysis of 729 children and the Duke University Health System C. diff testing study show the field is building comparable datasets to test infection mechanisms.
The research is at an early stage, so no screening tools or treatments are available yet. Patients with recurring urinary tract infections or C. diff could eventually benefit if the work leads to tests that avoid disrupting beneficial gut bacteria, but no timeline has been announced.
The takeaway
Watch for the first published findings from the WashU and Northwestern team on which gut bacteria traits predict infection. Any such results will show whether screening tools that spare beneficial microbes are feasible.
Further reading
Explore more Life Sciences coverage to see how microbiome research is reshaping infection treatment.
Source note: This article includes information reported by St. Louis American.
