Gut microbiota can influence metabolic events and synthesize neurotransmitters, impacting the body and brain indirectly.

“But as it turns out, the gut microbiota are capable of influencing metabolic events and in some cases are capable of synthesizing neurotransmitters themselves. So what that means is that these little bugs, these little microbiota that are cargo in your gut, the six pounds of cargo, they actually can make neurochemicals that can pass into the bloodstream and into your brain and actually impact the other cells of your body and brain indirectly, so without involving these very intricate nerve pathways that we've been talking about.”