Our Microbiome Minute series is back, where experts from the AGA Center for Gut Microbiome Research & Education break down the most interesting research developments in this space with 1-minute summaries.
Sara Di Rienzi, PhD, provides a review of the article, “Dietary fiber modulates the window of susceptibility to Clostridioides difficile infection,” published in Gastroenterology by Katharine K. Hewlett, et al.
Clostridioides difficile causes debilitating and possibly life-threatening intestinal infections in half a million patients in the US yearly. Individuals typically acquire C. difficile when their normal gut microbiota is severely reduced by antibiotics or another condition. Work by Hewlett and colleagues fortuitously observed in a small clinical trial and reproduced in a mouse model that a low-to-no fiber diet increases susceptibility to C. difficile after microbiome depletion by antibiotics. Mechanistically, they identify the loss of obligate anaerobes and an increase in facultative anaerobes, and the associated increase in primary bile acids and loss of secondary bile acids as factors increasing C. difficile infection susceptibility. As primary bile acids promote C. difficile growth while secondary bile acids suppress C. difficile growth, they postulate that a low fiber diet promotes an intestinal environment that promotes C. difficile infection. Hence, fiber consumption should be considered in the context of patients undergoing antibiotic treatment to prevent C. difficile infection.

Sara Di Rienzi, PhD
Rutgers University