Ecological and dietary strategies to constrain Clostridioides difficile.

Clostridioides difficile exemplifies a pathogen that leverages its metabolic plasticity to exploit nutrients that become available during community disruption, including host and microbiota-derived metabolites and substrates enriched in modern diets. These ecological dynamics underpin the high and growing burden of C. difficile infection (CDI), including recurrent disease and the rising prevalence of community-associated CDI. Fecal microbiota transplantation and standardized stool-derived products consistently re-establish colonization resistance through convergent functions that include secondary bile acid restoration, nutrient niche exclusion, and suppression of opportunistic pathogens. These principles have provided a valuable roadmap for rational consortia design. In this review, we synthesize current ecological mechanisms governing C. difficile colonization, persistence, and recurrence, highlight missing dimensions in diet intervention studies and mucosal colonization by C. difficile, and propose an ecology-informed, artificial intelligence-enabled precision framework that integrates host susceptibility, exposures, diet, community function, and pathogen features to guide personalized prevention and treatment.