The Gut-Brain Axis: How Your Diet Affects Your Mood

Your gut and brain talk to each other constantly, through the vagus nerve, the immune system and the chemicals made by the trillions of microbes in your digestive tract. Around 90% of the body's serotonin, one of the main chemicals involved in regulating mood, is made in the gut.

Those microbes eat what you eat. A good target is 30 different plant foods a week; vegetables, fruit, whole grains, beans, nuts and seeds all count. Fermented foods such as live yoghurt, kefir and sauerkraut add live cultures on top.

At the other end of the scale, diets heavy in ultra-processed food are consistently linked with lower mood and higher anxiety in research studies. You don't have to be perfect about it. Shifting gradually towards whole foods makes a measurable difference within weeks.

Some medicines can affect the gut too, including certain antibiotics and long-term acid suppressants. If you take regular medication and struggle with digestion or low mood, ask our pharmacists to review your medicines.

If a full diet overhaul feels daunting, start with one change: an extra portion of vegetables a day, or a live yoghurt at breakfast.