Bacterial brain benefits

We know from work done on mice raised in entirely sterile environments that an absence of healthy bacteria leads to changes in how the blood–brain barrier functions. This matters because the barrier plays a critical part in keeping out materials and pathogens that have no business hanging around in the brain. In contrast, administration of probiotics has been shown to restore both intestinal function and brain chemistry. Given these findings, researchers have speculated that concurrent treatment of probiotics while patients are taking antibiotics should ameliorate the damage caused by the antibiotics but evidence for this has been thin. Now a new study conducted in mice is revealing that this is something that is well worth further attention. 

In the new work, researchers dosed baby mice with penicillin one week before birth and then continued giving it to them until they weaned. Throughout this process, they simultaneously monitored the bacteria in their guts, their behaviour and the integrity of their blood brain barriers. Remarkably, they found that, like mice raised in completely sterile environments, the antibiotic-treated mice had lasting changes in the bacteria found in their guts, modified blood brain barrier integrity and showed behavioural changes like increased aggression and reduced sociality. More importantly, they found that the use of probiotics partially prevented these negative effects. You can read more in The Economist article that I wrote on this here.