Feed Your Gut Microbiota for Improved Health

Humanized microbiota Swiss Webster mice infected with C. difficile
efficiently clear the pathogen when maintained on a diet with
microbiota-accessible carbohydrates (MAC+), but remain persistently
infected when on a MAC-deficient diet (MD1, MD2). Switching from a
MAC-deficient diet promotes rapid pathogen clearance. Figure from
Hryckowian et al.¹

Clostridium difficile is a significant source of infectious disease death in the United States, and C. difficile infection can be difficult to treat. Many researchers are focusing on new therapies for this major health problem, including clinical use of fecal microbiota transplantation. Dietary manipulations are another avenue of study. Researchers at the Stanford University School of Medicine recently published a paper in this vein entitled "Microbiota-accessible carbohydrates suppress Clostridium difficile infection in a murine model" in the journal Nature Microbiology.

Hryckowian et al. generated humanized microbiota mice by colonizing germ-free Swiss Webster mice from Taconic Biosciences with healthy human donor microbiota. In an antibiotic-induced C. difficile infection model, the humanized microbiota mice maintained on a diet containing microbiota-accessible carbohydrates (MACs) efficiently cleared the pathogen, whereas humanized microbiota mice maintained on a diet deficient in MACs had persistent infection for a prolonged period. Similar results were observed in conventional microbiota Swiss Webster and C57BL/6NTac mice as well as germ-free Swiss Webster mice which were associated with a conventional mouse gut flora¹.

The researchers hypothesize that MACs may act in two ways to control C. difficile:

As the authors write, this study "is part of a growing body of literature providing evidence that dietary manipulation of the metabolic networks of the intestinal tract is a powerful and underexplored way to influence gastrointestinal pathogens¹."

Reference:

1. Hryckowian, A. J.; Treuren, W. V.; Smits, S. A.; Davis, N. M.; Gardner, J. O.; Bouley, D. M.; Sonnenburg, J. L. Nature Microbiology. 2018.