The Gut Microbiome Derived from Anorexia Nervosa Patients Impairs Weight Gain and Behavioral Performance in Mice

It was previously established that anorexia nervosa (AN) results in gut dysbiosis; however, whether this can actually contribute to AN-specific pathologies such as poor weight gain and neuropsychiatric abnormalities remains unclear. Therefore, germ-free mice were reconstituted with the microbiota of anorexia nervosa restricting-type patients (gAN mice) and healthy control individuals (gHC mice), and the effects of gut microbes on weight gain and behavioral characteristics were examined. Fecal microbial profiles in recipient gnotobiotic mice clustered with those of the human donors. Despite no difference in food intake between the two groups, body weight gain was impaired in gAN mice. In addition, anxiety-related behavior was increased only in gAN mice compared to that in corresponding gHC animals, and this phenotype was reversed through the administration of Bacteroides vulgatus. Collectively, these results indicate that AN-specific dysbiosis might contribute to both poor weight gain and mental disorders identified in AN patients.