When I was young I travelled extensively and, because I was living cheaply, I got a range of interesting tropical diseases, including some exotic gut infections. More recently, I deliberately infected myself with tapeworm for the BBC Four programme Infested. Despite all this, I have never had any long-term gut problems. Other people are not so fortunate.

Gut problems are remarkably common, with irritable bowel syndrome (IBS) being one of the most common, affecting around 1 in 5 people at some point in their lives. Symptoms include stomach cramp, bloating, and either diarrhoea or constipation. It often gets worse in sufferers when they hit their 30s.

British doctors are not great at helping people with IBS, which is often dismissed as ‘psychosomatic’. Although there is a psychological component to IBS, you may have heard that it can be treated – in the majority of cases – by going on a temporary, restricted diet called the ‘low FODMAP diet’.

Could a diet help ease the misery of IBS for millions of sufferers? © joe waldron
© Joe Waldron

There is an increasing amount of evidence that this diet can help people with IBS by altering the trillions of microbes in the gut. Research shows that the mix of bacteria in the guts of people with IBS tends to be different from those of the average, healthy person. The result is that when someone with IBS eats certain foods, they blow up with gas. That’s because they are feeding a host of ‘bad’ microbes that have taken up residence in their digestive tract.

FODMAP stands for ‘fermentable oligosaccharides, disaccharides, monosaccharides and polyols’. These are the scientific terms used to classify carbohydrates found in many foods that are notorious for triggering symptoms such as bloating, gas and stomach pain. Doing a low FODMAP diet involves cutting down on sugars, refined starchy carbohydrates – those found in potatoes, bread and pasta – as well as dairy products, wheat, rye and most processed foods.

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You also have to cut out a surprising number of ‘healthy’ fruits and vegetables, including apples, peaches, pears, cauliflower, leeks, garlic and onions. Excluding these foods for 6 to 8 weeks lets the gut calm down. You can then reintroduce ingredients one at a time to see which ones are triggering the IBS.

The diet was developed by scientists at Monash University in Australia and research has shown that it can help to reduce symptoms in around 75 per cent of people with IBS (find out more at monashfodmap.com).

But it’s not only IBS that can be relieved. A small study published by King’s College in October this year showed promising evidence that a low FODMAP diet could even ease symptoms of inflammatory bowel diseases (IBD) like Crohn’s and colitis. Clearly, more studies need to be carried out, but it’s certainly an interesting time for gut research.

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Dr Michael Mosley is former medical doctor, health writer and BBC presenter. He’s best known as presenter of Trust Me I’m a Doctor on BBC Two but has also written a number of bestsellers about personal health and medicine, including The Fast Diet, Fast Asleep and Fast Exercise.