The Gut-Brain Axis: How Your Gut and Brain Stay Connected

By Dr See Lay May, Gastroenterologist and Hepatologist 

The gut-brain axis is the complex communication network that links your Gastrointestinal tract and your central nervous system. It plays a vital role in maintaining overall health and has significant influence on mood cognition, digestion and even immune function. 

Trillions of microbes (bacteria, fungi, viruses) living in the gut produce neurotransmitters (like serotonin, dopamine, cortisol) and metabolites (like short-chain fatty acids) that affect brain function. The gut houses about 70% of the body's immune cells, so inflammation in the gut can affect brain health and vice versa.  

How diet and lifestyle influence the gut - brain axis 

Diet 

• High-fibre, plant-based diets support a healthy microbiome  
• Fermented foods (yoghurt, kefir, kimchi, sauerkraut) - provide probiotics that regulate mood and digestion and avoiding ultra processed foods which harm microbiome 
• Polyphenol-rich foods (i.e. green tea, berries, dark chocolate) support gut and brain health by reducing inflammation 

Probiotics- improve mood and support gut function. 

• Sacchromyces Boulardii (Bioflore) prevents and treats diarrhoea and supports microbiome recovery 
• Lactobacillus good for diarrhoea, IBS, leaky gut and bloating 
• G-NiiB is great for IBS and impaired immunity. Some evidence to support COVID recovery and preventing colon cancer 

Lifestyle 

• Exercise improves both gut motility, mood and brain function 
• Sleep: gut health influences circadian rhythm. Have a consistent bedtime, 7-9 hours of quality sleep, reduce screentime before bed. 
• Stress management (medication, yoga, tai chi): chronic stress harms the gut and disrupts brain function.