OVER the past few years, gut health has become a hot topic in scientific research, and studies have shown just how important maintaining a healthy digestive system can be - not just for physical health, but for our mental wellbeing too.

Poor gut health has been linked to a number of issues ranging from obesity and diabetes to rheumatoid arthritis, irritable bowel syndrome and depression. Experts are dubbing the area the body's 'second brain', believing microbes and nerves in your digestive tract can effectively alter everything from hunger pangs to your mood.

If you've been feeling 'off' recently, your inharmonious gut flora could be to blame, but with 100 trillion bacteria living in your gut - both beneficial and pathogenic - maintaining the ideal balance can be tricky.

We asked Liz Earle, author of The Good Gut Guide (£25, Orion Spring), to share her top tips for keeping your digestive system in good shape.

1. Take a daily probiotic: "Although it won't undo an unhealthy diet, taking a multi-strain probiotic each day (ideally one that includes at least eight different strains) is a useful insurance policy, alongside a diet filled with fresh and fermented foods. It can also help speed up the transit time of food and waste matter passing through your body, easing and regulating bowel movements."

2. Drink fermented beverages: "Why not wash down your probiotics with a zingy kombucha shot or a glass of milk kefir? I start my day with a glass of kefir - a live yoghurt drink packed with powerfully beneficial probiotics, and I find this gives me a real boost in the morning and has made a huge difference to my overall health and wellbeing. I make my own kefir at home using kefir grains and cow's milk, although you can use coconut milk, coconut water or any other nut 'milks'."

3. Go organic: "Buy fresh produce from farmers' markets or look in supermarkets for loose organic fruit and veg that have yet to be scrubbed clean. This is such an easy way to take on board the healthy soil-based bacteria that help improve digestive and immune functions."

4. Exercise: "Daily exercise keeps your gut moving - even just a short daily walk in the fresh air can make all the difference to keeping your gut healthy. Five to 10 minutes of meditation at the beginning or end of the day can also help relax both brain and gut, which will boost your overall wellbeing. I'm a recent convert to running and enjoy early-morning runs around my West Country farm, or a park if I'm in London."

5. Give your gut time to rest: "It's really important to allow our body, and therefore our gut, to rest from time to time. Whenever possible therefore, try to rest your gut overnight, allowing a clear 12-hour window when nothing is eaten. It's also worth considering juice-only days to fully rest your digestive system - I try to have a juice cleanse at least twice a year. Juices are natural cleansers and a quick and easy weekend reboot can make a real difference to how we look and feel."