'Gut health' is the wellness industry's buzzword of choice right now, with UK sales of digestive remedies set to reach £333 million by 2021. There's been some pretty groundbreaking research of late into a part of the body that, until relatively recently, has been taken for granted. So what does science actually now know about how the gut works, and does the secret to a healthy gut really lie in overpriced yoghurt drinks and chia seeds? Microbiologist Dr. Lindsay Hall is a research leader at the Institute of Food Research, and she really knows her bacteria. "The gut provides a home to trillions and trillions of beneficial microbes," she explains. "This complex ecosystem is called the microbiota, and the number of bacteria we have in our gut day-to-day is equivalent of about 2-3kg. We've known about these bacteria for years, but it's only really in the last 15-20 years – and, in a really focused way, in the last five years – that we've begun to understand the different health benefits that these bacteria actually provide us with." If you're anything like me, your knowledge of this complex microbial ecosystem probably begins and ends with the words 'good bacteria' and 'bad bacteria'. Years of yoghurt adverts where women complain about bloating before eating a magic fromage frais and having a giggle about nothing in particular have taught us that not all bacteria are bad. But in fact, the impact they have on our body – and potentially, our brain – is incredible. "The health benefits are fairly far-reaching. Obviously all this research is still ongoing, but it's all really, really exciting," Lindsay says. "Gut microbes are important in terms of modulating our gut function – so, transit time after a meal, keeping you regular, and maintaining a healthy barrier between what's in the gut and what's in the body. They're also super important for regulating your immune system, so they programme your white blood cells and tell them what to do, and they actually help us digest our food and extract energy and other key nutrients from it," she explains. So far, all pretty essential – but the theory currently at the forefront of research, Lindsay adds, is that gut bacteria can even control your brain function. Yeah, that stuff Martine McCutcheon was on about might just be that important. And the scientific developments don't end there. "Microbes basically impact on everything, in terms of the stuff we take for granted on a day-to-day basis to keep us healthy. The problem is, because these bugs are so important, if we come in and potentially disturb them – which we can do a number of different ways – that may mean it leads to disease," Lindsay says. "At this point in time, the research suggests that the microbiota is important in certain diseases. Allergies like eczema and asthma, or chronic inflammatory diseases like ulcerative colitis, potentially type 2 diabetes, are some of the diseases currently being tested in pre-clinical models."
The war on carbs has been a disaster for many people's gut health
But while the implications of this research are potentially huge, the difficulty lies in the fact that no two gut microbiota are the same. So while we know that gut health is hugely important, and could lead to exciting advances in personalised medicine, the current advice on keeping your gut healthy is far less exciting. "It's actually quite boring, common-sense stuff – a varied diet, taking on lots of fruit and veg, protein, carbohydrates, and keeping quite active," Lindsay says. One woman who's done plenty of her own reading up is Karen Collins, founder of The Happy Tummy Company, who spent years researching and developing a product to treat her severe, lifelong constipation irritable bowel syndrome (IBS). The result was her signature chia teff loaf, produced in Hackney and delivered by bike around London on a subscription ordering service. But many of the other changes Karen has made are far more ordinary, and based on her research into good old-fashioned fibre. "Fibre is very, very important for gut health, and making things from scratch is the other crucial thing," she says. "Having porridge with fresh fruit for breakfast is great. Having a lunch of beans with a wholegrain, an egg, and other vegetables is great. Having a dinner of brown rice and a chicken curry is great. You can still use hacky ways of making a meal simple and quickly, just steer away from those Dolmio sauces and things with lots of sugar in," she adds. "A third of your plate should be some kind of grain, nut or seed, another third should be plants, and then some protein." Karen passionately believes the war on carbs has been a disaster for many people's gut health, thanks to diet trends like clean eating, Paleo, Atkins and Dukan. "I've spoken to so many women, particularly in their 40s, who completely eradicated bread, pasta, all these carb foods, thinking they were bad. They were completely constipated!" she says. "It's horrendous. Eat bread every day, eat pasta twice a week – just make the switch from white to wholegrain, because that's where the insoluble fibre is, which acts as a natural laxative." When it comes to getting the right fibre, Karen explains: "We're meant to eat a ratio of three parts insoluble fibre to one part soluble fibre. Insoluble fibre is in the skin or the bran of everything – fruits, vegetables, grains – and the biggest source of soluble fibre is any bean or oats, which are great for keeping you full on the go." Of course, as we know from Lindsay, what's worked for Karen's IBS constipation won't necessarily work in the same way for everyone – but both women stress the importance of figuring out what your own particular gut bacteria need, and staying savvy about the 'gut health' claims made by wellness firms, particularly when you encounter terms like 'probiotic' (which feeds bacteria) and 'prebiotic' (which fertilises gut bacteria).
A third of your plate should be some kind of grain, nut or seed, another third should be plants, and then some protein.
"In Europe all products have had to remove the term 'probiotic' from them because currently the European Food Safety Authority don't think the science is good enough behind those products. A lot of commercial products currently on the market don't even make it through the digestive environment," Lindsay says. "But if you want to try something, it's important to look at the numbers of bacteria – you need big numbers, billions if not trillions of bacteria. Something with 10 bacteria in is not even going to touch the sides." For Karen, the impact of the gut health trend has helped to grow her customer base, but she's concerned about the number of 'wellness' firms jumping on the probiotic bandwagon to sell products that are nowhere near as nourishing or wholesome as the bread into which she's poured her heart and soul. "A lot of the products on the market are like de-bloat and prebiotic capsules, but you would only ever have to buy that to unclog bad food that you ate," she says. "It's best just to eat efficiently and eat to nourish the body." Indeed, when it comes to natural probiotics and prebiotics, her advice is to eat bananas, apples, raw garlic, onions, homemade hummus, teff and natural, live yoghurt, rather than spending money on supplements like inulin, unless you really need to. "I'm not making sacrifices," she says. "I eat pizza, I drink wine, I'll have a beer; if I want chocolate, I'll have some chocolate – but I've got good energy, I don't get sick, and I work hard. It's feeding my gut with these consistent sources of nourishment that makes the difference."