Female mice that eat a high-fat diet produce litters with social deficits that are linked to changes in the offspring's gut bacteria.
Mauro Costa-Mattioli at Baylor College of Medicine in Houston, Texas, and his colleagues compared offspring from mothers that ate a high-fat diet with those from mothers on a normal diet. The high-fat-diet offspring spent less time interacting with other mice, and had reduced bacterial diversity in their guts. In the animals' brains, researchers found fewer neurons containing oxytocin, a hormone that is related to social behaviour. Electrical signalling in the ventral tegmental area, a brain region that processes rewarding stimuli, did not strengthen as it normally does following new social interactions.
The team identified a gut bacterium, Lactobacillus reuteri, that reversed these abnormalities when it was given to the high-fat-diet offspring.