When mothers suffer from obesity while they are pregnant their children are more likely to develop autism. Why this is has remained a mystery but a team is now shedding some light on the subject by revealing that there is an important relationship between a gut dwelling bacterium and the production of a hormone that plays a key part in making us social.
The work began with the researchers demonstrating that when mouse mothers were fed large meals that made them obese their offspring developed abnormal bacterial populations in their guts as well as the rodent equivalent of autism*. They then noticed that when the mice were given probiotics that normalised their gut bacteria, the autism went away.
A closer look at the hormone systems in these mice revealed that a single species of bacteria that usually lives in the guts of mammals seems to be important for switching on production of a social hormone (oxytocin) which helps to remove many problematic autism traits. You can read more in The Economist article that I wrote on this subject here.
*In case you are wondering, rodent autism is diagnosed when mice would prefer to socialise with inanimate objects (like an empty cup) than other animals and when they prefer to follow the same path through a maze over and over again.