Human intestinal microbiota gene risk factors for antibiotic-associated diarrhea: perspectives for prevention. Risk factors for antibiotic-associated diarrhea

28 Antibiotic-associated diarrhea (AAD) is associated with altered intestinal microflora and other 29 symptoms that may lead to possibly death. In critically ill patients, diarrhea increases rates of 30 morbimortality. Assessing diarrhea risks is thus important for clinicians. For this reason, we 31 conducted a hypothesis-generating study focused on antibiotic-associated diarrhea (AAD) to 32 provide insight into methods of prevention. We evaluated the hypothesis of predisposing 33 factors within the resident intestinal microbiota in a cohort of outpatients receiving 34 antibiotherapy. Among the pool of tested variables, only those related to bacterial 16S rRNA 35 genes were found to be relevant. Complex statistical analyses provided further information: 36 amid the bacteria 16S rRNA genes, eight were determined to be essential for diarrhea 37 predisposition and characterized from the most important to the least. Using these markers, 38 AAD risk could be estimated with an error of 2%. This molecular analysis offers new 39 perspectives for clinical applications at the level of prevention. 40 41