In brief
The links between the gut and the brain. Nerves let the brain speed up or slow digestion, stress can upset the gut, and researchers are studying how gut microbes may affect the brain.
- Gut microbes may have a role in anxiety and depression, but more research is needed, according to the Australian Academy of Science.
- IBS triggers include diet, stress, infection and some medicines, according to healthdirect.
- Relaxation techniques can help you manage stress and boost your ability to cope.
How it works
The bowel has its own separate nervous system, the enteric nervous system. The brain's automatic nerves also act on the gut. The parasympathetic system stimulates digestion, while the sympathetic system, which prepares the body for activity, slows it. Stress can affect digestion, and it is one of the triggers of irritable bowel syndrome (IBS).
Some studies have found a connection between gut microbes and the brain, and gut microbes may play a role in anxiety and depression. This research is still in its infancy, most of it has been done in rodents rather than people, and there is no conclusive evidence that serotonin made by gut microbes reaches the brain.
Connections
4 connections on the map. Select a topic to read its page.
Gut-brain axis is linked with
Stress can affect digestion, according to healthdirect.
Source: healthdirect Australia, Stress
- Irritable bowel syndrome (IBS) Supported
IBS symptoms can be triggered by stress, according to healthdirect.
Source: healthdirect Australia, Irritable bowel syndrome (IBS)
- Gut microbiome Emerging
Research on gut microbes and the brain is still in its infancy, and most studies have been done in rodents rather than people.
Source: Australian Academy of Science, Gut bacteria: the inside story
Gut-brain axis is part of
The bowel has its own nervous system, and the brain's automatic nerves speed up or slow digestion.
Source: InformedHealth.org (IQWiG), NCBI Bookshelf, In brief: How does the nervous system work?
Sources
- In brief: How does the nervous system work?
- Gut bacteria: the inside story
- Irritable bowel syndrome (IBS)
- Stress
Each connection above names its own source. See every source AskBioMap uses.
Summarised from InformedHealth.org, the Australian Academy of Science and healthdirect. Sources read on 13 and 16 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.