Deoxycholic and lithocholic acids produced by this system contribute to its “colonization resistance” properties. For 10 points each:
[10m] Name this system, which is disrupted by repeated antibiotic use during opportunistic C. difficile infections. Indole propionic acid produced by this system is a potential antioxidant once it crosses into the CNS.
ANSWER: gut microbiome [or gut microbiota; or gut bacteria; or gut flora; or gut microbes; or gastrointestinal microbiome; or gastrointestinal microbiota; or gastrointestinal bacteria; or gastrointestinal flora or gastrointestinal microbes; accept microbiota–gut–brain axis; prompt on microbiome or microbiota or flora; prompt on intestines or guts or GI tract or digestive system; prompt on gut–brain axis]
[10h] Metronidazole and this glycopeptide antibiotic are commonly used to treat C. difficile infections at the risk of microbiota depletion. Lactobacillus rhamnosus strains can treat Enterococcus resistant to this antibiotic, which is conferred by a lactate for alanine substitution.
ANSWER: vancomycin [or oral vancomycin; accept vancomycin hydrochloride]
[10e] Gut microbiota also produces short-chain varieties of these molecules like IPA and butyrate that can moderate immune responses in the GI tract. Dietary fish oil provides omega-3, -6, and -9 varieties of these molecules.
ANSWER: fatty acids [accept short-chain fatty acids; accept omega fatty acids; prompt on fats or lipids; prompt on carboxylic acids; prompt on FAs or SCFAs]
<AL, Biology>