The gut microbiota controls immunity and brain function, but its role in cognitive aging is unclear. Boehme et al. found that fecal microbiota transplantation from young into aged mice attenuated cognitive impairments and reversed differences in hippocampal metabolites, and some aspects of peripheral and brain immunity. Rochellys Diaz Heijtz, Ayoze Gonzalez-Santana and Jon D. Laman for more details click here