You’re only as healthy as your gut microbes. To help avoid constipation, ‘leaky gut’ and low mood we need to feed them their favourite foods, says nutritional therapist Petronella Ravenshear

Any products in this article have been selected editorially however if you buy something we mention, we may earn commission

It sounds like science fiction – the idea that the bugs in our gut can affect our mood. And not only our mood but also our weight, our behaviour, our food choices and even the risk of developing heart disease, breast cancer or diabetes. But the latest research is showing just that. We’re also seeing the connection between a lack of our friendly microbes and conditions such as IBS, leaky gut and allergies. Some researchers believe that the increasing rates of autoimmune diseases may be due in part to a disruption of the relationship between our bodies and our “old friends” (a term coined by Professor Graham Rook at UCL ), the microbes with whom we co-evolved.

The mitochondria, which produce energy in our bodies, resemble bacteria and they have their own DNA. Scientists theorise that millions of years ago we set up a pact with these bacteria; we would keep them warm and well fed and in exchange they would provide energy for us. And it seems we have made a similar pact with the microbes in our gut; if we give them the kinds of fibre and plant foods that they like, they in turn help us digest our food, make vitamins for us, supply us with energy, keep us ‘regular’, train up our immune system, reduce inflammation, keep the lining of our gut in good repair and they can even protect us from anxiety and depression.

Leaky gut? Constipation? Microbes to the rescue!

The age-old advice to get our roughage and eat our greens is spot-on and exactly what it takes to feed our friendly microbes. It’s beginning to dawn on us that we are only as healthy as our microbiome, which is the collection of bacteria in our gut. What’s good for them is good for us. We don’t need fibre for its pot scouring effects on our intestines, we need it to feed our friendly bacteria. These amazing creatures help with the peristaltic action of the gut and they also add bulk to the stool (making it easier to go to the loo).

And there’s more! Another really helpful job they do is to make the lining of the gut more resilient and less ‘leaky’. A single layer of cells, just one cell layer thick is all that separates the gut from the rest of the body. When the so-called ‘tight junctions’ between these cells open (as they can sometimes do when we are stressed or eat gluten) this can lead to a leaky gut in which all kinds of proteins and pathogens escape from the gut into the bloodstream. The net result of that is that the immune system is activated, which can lead to allergies and even autoimmune disease, and a chronically activated immune system saps our energy.

MORE GLOSS: How to boost your gut health on a budget

Research is showing us that good health is equated not only with high numbers of microbes but also with lots of different species of microbes. A lack of fibre and a lack of variety of foods, especially plant foods, in our diet result in fewer numbers and fewer species of microbes. It’s an odd idea but each species has its own favourite types of fibre, so something we can easily do is to be more adventurous in terms of the vegetables we eat. Think about making a list of all the herbs, vegetables and fruit that you eat on a weekly basis and work on expanding it.

Potatoes have been shunned by dieters for years, but the latest research shows that we can cautiously welcome them back into our diet. When we cook potatoes and allow them to cool for a few hours before eating, the carbohydrate structure changes and more resistant starch forms; resistant starch is one of the microbes’ favourite kind of fibre. Other favourite foods include artichokes, garlic, onions, and chicory root.

MORE GLOSS: Fermented beauty - a fad or the future of skincare?

Some types of bugs are good at extracting calories from foods and make us fatter, while others, most notably Christensenella, are associated with a lean body. There’s an exciting new DNA stool test available, Professor Tim Spector’s Map My Gut, which not only reports on our individual microbiome but also compares it to the national average and to Tim Spector’s microbiome. Fast food fans are likely to see low levels of Firmicutes and high levels of Enterobacteriaceae and imbalances of these bugs are associated with inflammation and overweight. The exciting thing is that we can alter our microbiome by altering our diet and this can result in improved health and energy and even weight loss.

It has to be said that the goodies, our friendly microbes, are somewhat weedy. They don’t like flying, loud music, alcohol (apart from an occasional glass of good red wine), junk food or emotional stress and their biggest enemy is antibiotics. We are finding out that they are also affected by artificial sweeteners and the kinds of emulsifiers and preservatives found in fast and packaged food. Some of us have first-hand experience of one of the less friendly gut bugs, candida, which can flourish when defences of our normal bugs are low. An overgrowth of Candida, commonly seen as thrush following a course of antibiotics, sends powerful messages to the brain to go and find sugar – not good. So how can we nurture the goodies?

How to nurture our friendly microbes

1. Eat fermented foods – like yoghurt, sauerkraut, raw cheese, kefir, miso and apple cider vinegar – N.B. if you suffer from bloating or pain, start very slowly as foods like sauerkraut can initially make bloating worse.

2. Widen the variety of vegetables, herbs and plant foods you eat – each microbe has its favourite type of plant fibre.

3. Include organic coffee, green tea, dark chocolate, a little red wine, extra virgin olive oil and berries daily – the polyphenols (plant antioxidants) they contain are beloved by our microbes.

4. Deal with stress – yoga and meditation are great stress relievers, but so is anything that gets us in ‘the flow.’ Being in the flow means being absorbed by what we are doing, whether it’s studying, reading or cooking (TV doesn’t count).

5. Practice intermittent fasting (try skipping one meal a day and eschew grazing in favour of eating two meals a day without snacking). When we fast, the bugs can get on with their housekeeping tasks, which include pruning the gut lining and helping to make it stronger.

Follow Petronella on  Twitter .