Infant gut microbiota contributes to cognitive performance in mice

Abstract

Gut microbiota has been related to infant neurodevelopment. Here, an association between infant composite cognition with gut microbiota composition was established as soon as 6 months. Higher diversity and evenness characterized microbial communities of infants with composite cognition above (Inf-aboveCC) versus below (Inf-belowCC) median values. Metaproteomic and metabolomic analyses established an association between microbial histidine ammonia lyase activity and infant histidine metabolome with cognition. Fecal transplantation from Inf-aboveCC versus Inf-belowCC donors into germ-free mice showed that memory, assessed by novel object recognition test, was a transmissible trait. Furthermore, Inf-aboveCC mice were enriched in species previously linked to cognition belonging to Bacteroides, Phaeicola and Bifidobacterium. Finally, Inf-aboveCC mice showed differential faecal histidine, hippocampal urocanate and histidine-urocanate-glutamate ratios compared to Inf-aboveCC mice. Overall, these findings reveal a causative role of gut microbiota on infant cognition pointing at modulation of histidine metabolite levels as a potential underlying mechanism.