Microbial communities in the body can influence the brain in a lot of ways. The gut-brain axis refers to the communication between the gut and the brain and since microbes play a large role in the gut they have an impact on this communication. Certain microbes may induce the release of specific neurotransmitters that impact mood or cognition which influences mental health states. If microbes impact receptors in the gut in any way it can influence the brain which can alter mental health states. In the reverse concept, the brain and mental health can also influence microbial communities in the gut. Some mental illnesses greatly increase or decrease certain hormones and neurotransmitters which can impact the gut. There is also something to be said about the physical symptoms that certain mental health states induce. For example, someone with anxiety may experience a lot of nausea which can impact the gut microbiome. To go one step further, some of the medications provided for mental illnesses may also influence the gut microbiome. Overall, the brain and the gut have a strong two-way connection.
