Can Changing Gut Flora Reduce Medication-Induced Metabolic Effects?

In animals and humans, differences in gut microbial flora are associated with variations in body weight and fat deposition, and transplants of gut microbes from lean humans have decreased obesity in mice (Science 2013; 341:1241214). Because olanzapine alters fecal microbiota in rats, gut flora might be related to olanzapine's metabolic effects. These researchers investigated whether administering antibiotics to change gut microbial flora might minimize olanzapine's obesogenic effects.

Weight-matched female rats received an antibiotic cocktail of neomycin, metronidazole, and polymyxin (a mixture that effectively sterilizes the gut) or neutral vehicle for 5 days and then began coadministered olanzapine or vehicle for 21 days. Olanzapine alone …