Do you ever get a “gut feeling” about something, experience “butterflies in your stomach” when nervous, or experience a worsening of your IBS when stressed? These could be signals sent by your “second brain” – located in your gut.
 
The gut-brain axis is the bidirectional relationship between the central nervous system (brain and spinal cord), the intestines, the gut microbiota, and the immune system. It involves complex interactions between cognitive and emotional centres within the brain and gastrointestinal functions. The bi-directional relationship is such that the brain influences intestinal function, while the gut and microbiome may influence brain function.
 
The relationship between the gut and the brain is complex, and we are still discovering the mechanisms by which they influence each other. It is likely that gut microbes play a key role in sending and receiving messages between the gut and the brain. The brain and GI tract are connected via the vagus nerve. Sensory neurons carry feedback from the intestines to the brain stem, which then interacts with the hypothalamus and limbic system. Additionally, the limbic system influences autonomic activity of the gut when activated by stress.  
 
Research suggests that the gut-brain-axis is involved in IBS and digestive dysfunction, immune function, healthy stress response, and a number of neuropsychiatric disorders including anxiety and depression. As such, taking care of our gut and our brain is likely to have far reaching impacts on our health and wellbeing.
 
Reduce stress
 
Chronic stress has been linked to increased intestinal permeability (sometimes called ‘leaky gut’), which has been implicated in a number of neuropsychiatric conditions including anxiety and depression. Chronic stress is also considered a driver of IBS symptoms. Stress reduction techniques such as meditation, social connection, exercise and counselling may be supportive of the gut-brain-axis.
 
Consume a wholefoods, anti-inflammatory diet
 
An anti-inflammatory diet is based on wholefoods, so consume plenty of fruit, vegetables, grains, nuts and seeds, and adequate protein. Minimise the consumption of inflammatory foods including processed foods, trans fat and refined carbohydrates. This will support a healthy gut microbiome, and in turn, healthy messaging between the gut and the brain.
 
Include fibre, pre- and probiotics
 
Fibre, pre- and probiotics may support the composition, diversity and function of the gut microbiome. This may then modulate the immune system, support healthy messaging between the gut and brain, and influence mood and behaviour.
 
Stimulate the vagus nerve
 
The vagus nerve is the main highway between the gut and the brain, and is key to healthy parasympathetic nervous system function (i.e. “rest and digest”). Research has demonstrated that a positive feedback loop exists between a healthy vagus nerve, physical and mental health. The more you support your vagus nerve, the greater your physical and mental health and visa versa. There are numerous ways to support vagal nerve health including deep breathing, cold exposure, singing, humming, gargling, meditation, laughing, and probiotic supplementation.
 
Despite the complexity of the gut-brain-axis and its relationship to various disease processes, there are a number of supportive dietary and lifestyle practices that may improve the health of both the gut and the brain and the pathway between the two.