Brrring' brrring'. Hello? I'm having a problem with bacteria ruling my brain! (laugh) Norbert's always had that problem! You know, this reminds of me Click and Clack, the Car Talk Guys. One of the hosts, Tom Magliozzi, just passed away. They had a blast with the show while still being informative. We dedicate this episode to his memory.

What's on my mind is the accumulating evidence that the bacteria in our gut affects our brain, impacting emotions and behavior! One study compared MRI brain scans from people with different microbiome in their gut. There were differences in the wiring of their brain regions based on which types of bacteria were dominant.

In a mouse study, researchers took gut bacteria from meek, anxious mice and transplanted them into normal, curious to aggressive mice. Remarkably, the aggressive mice became timid and when they reversed the experiment, the timid mice became aggressive. Another mouse study found mice raised in sterile conditions so that they didn't develop gut flora, were socially stunted with autism-like behaviors.

A study with people found those who consumed two types of intestinal bacteria were less depressed and anxious after 30 days. Other imaging studies showed women who ate yogurt twice a day had changes in the brain area that processes emotions. Two possible mechanisms explain how gut flora influences brain function.

The gut, after the brain, is the largest source of nerve cells and a major nerve, the vagus nerve, runs from the abdomen to the brain. Second, bacteria may make their own neurotransmitters.

So, just who's in charge of our emotions and actions, us or our mind-molding microbes? We've got a lot more to learn about our bacterial friends!