A designed synthetic microbiota provides insight to community function in Clostridioides difficile resistance

Area of Science:

• Microbiology
• Gut Microbiome Research
• Infectious Disease

Background:

• Clostridioides difficile is a significant cause of antibiotic-associated diarrhea.
• The gut microbiome naturally suppresses C. difficile colonization, but mechanisms remain unclear.

Purpose of the Study:

• To elucidate the mechanisms by which the gut microbiome suppresses C. difficile.
• To develop a synthetic microbial community for C. difficile suppression.

Main Methods:

• Meta-analysis of 12 human studies to identify microbial networks associated with C. difficile suppression.
• Construction of a 37-strain synthetic fecal microbiota transplant (sFMT1).
• In vitro and animal model testing of sFMT1 efficacy and mechanism.

Main Results:

• The synthetic fecal microbiota transplant (sFMT1) suppressed C. difficile in vitro and in vivo.
• Bile acid 7α-dehydroxylation was not critical for sFMT1 efficacy.
• A single strain performing Stickland fermentation was necessary and sufficient for C. difficile suppression.

Conclusions:

• Nutrient competition is a significant mechanism for C. difficile suppression by the gut microbiome.
• Synthetic microbial communities offer a model for studying complex microbial community functions.
• This approach can leverage public sequencing data for microbiome research.