It's the latest wellness buzz, but how strong is the science behind gut health? Fleur Britten reports on the links between lifestyle and tummy trouble — while two writers test the advice that goes far beyond food.
We are, it appears, in the middle of a faecal fixation, with people downloading bowel movement journals and even packing off their own poo specimens — along with about £250 ($500) — for personalised readings. Plus, there has been an, um, explosion in the gut-health market, with millions supplementing their diets with expensive probiotics and fashionable ferments such as kombucha, kefir, kvass and skyr. According to the market research firm Fortune Business Insights, the global probiotics market is projected to be worth £43bn ($85bn) this year. With Google searches for "gut health" more than tripling in the past three years in the UK, the wellness world has gone potty for the gut microbiome.
It would seem that there is little this gastrointestinal-dwelling community of yeasts, bacteria, fungi and viruses can't fix, with claims ranging from asthma to cancer by way of period pain, acne, obesity and even anorexia. Kevin Whelan, professor of dietetics and head of nutritional sciences at King's College London, is circumspect, however. "I could give you a list as long as my arm on the pseudoscience around gut health," he says. Whelan's research team includes the author of Eat Yourself Healthy, Dr Megan Rossi, a registered dietician and microbiome researcher with a doctorate in gut health. He praises her "evidence-based" book as one that "debunks a lot of myths".
In the book, Rossi explains that the gut microbiome's responsibilities include making vitamins, hormones, chemical messengers (for example, serotonin) and amino acids. It also communicates with other vital organs, including the brain, liver and heart. And, she adds, it "may help balance blood sugar, lower blood fats, regulate appetite, facilitate communication with the brain and ultimately help prevent many diseases".
Exciting progress is being made around its impact on mental health, says Whelan. "We know that if you transfer the microbiome from a depressed person into a mouse, the mouse will develop depression." The past decade has seen a huge increase in our understanding of the microbiome, but, he cautions, "we're not there with how to apply that in clinical practice. We can't yet say, 'If you ate more apples, it would switch your microbiome in a certain way.' " Be warned, then, should anyone try telling you as much.
What we do know, he says, is that "if you increase the amount and diversity of fibre in your diet, you will increase the amount of healthy bacteria in your gut". As will a diverse Mediterranean diet. "It's not about taking supplements or having a low-fat diet, but switching from red meat to fish, and from saturated fats to mono- and polyunsaturated fats from olive oil and nuts, and eating lots of fruits and vegetables."
When it comes to the gut-health market, much is pure profiteering, he says. The evidence simply isn't available to support our spending. But the greatest pseudoscience crimes, he says, are misdiagnoses, where "alternative nutritionists are using unvalidated tests" to diagnose healthy subjects with problems such as gluten sensitivity or leaky gut. "And then everybody needs a probiotic to treat it. Well, that simply isn't the case."
Lorraine Candy, 51, editor-in-chief
Nearly every woman I know has tummy troubles. My own worries aren't serious, just niggling symptoms. I've had a lifelong problem with constipation and a painful tummy. When I was a child, a GP diagnosed it as "stomach migraines", with no treatment prescribed, bar not to worry so much (as if). I've been vegan, vegetarian and a meat-eater in my gastronomical adventures and noticed no marked changes. Mostly I've ignored these boring low-key ailments, but I bought Dr Megan Rossi's book for a friend, and 10 minutes into it, I realised I would be keeping it.
The advice made sense: more fruit and vegetables (vary it daily because you'd be surprised how easily you get into a rut), the occasional addition of fermented foods, going for high-fibre options in the canteen, stocking up on a variety of nuts and seeds, reducing red meat and making fish a bigger part of your diet.
The main change, however, hasn't been what I've eaten, but more the habits I have broken. I finally understand the link between gut and brain, which are always talking to each other like best friends.
Sleep is when your gut regenerates. I've changed my sleep routine and use the Calm app to help me stay in bed at night. (I've been known to wander the house during periods of insomnia.) More sleep equals less tummy trouble. Rossi basically advises I slow down, so my gut can also slow down. On her advice I get up a little earlier, drink a glass of water on my own and then have a coffee (it gets things moving). A busy life tells your bowel it is too busy to go to the loo, she explains.
The book is packed with recipes and meal plans, but you don't have to follow them to the letter and I didn't have time to prepare any of the meals for lunch in advance. She doesn't advocate probiotics unless specifically prescribed, is not a fan of fasting and is happy for you to have caffeine and alcohol in moderation. There is even a specially formulated prebiotic granola and a recipe for chocolate bark that is to die for. It's all common sense really, with some excellent nutritional science to back up her claims.
The one thing I would advise is to check your iron levels throughout this largely meat-free diet — mine dropped dramatically, leaving me at one point feeling exhausted. So Rossi advised I eat 70g of red meat a couple of times a week to redress the balance, which worked.
I feel lighter, less bloated and as if I have had a rebirth on the food front. Simply changing what I put on the weekly shop has been an adventure, but not a costly or complicated one, and I say that as someone with an extensive and fussy list of food no-gos.
Most important, I don't feel as if I have been tricked into the latest food cult fuelled by faddy habits that won't work in the real world.
Emily Clarkson, 25, writer and blogger
When it comes to my IBS, there is basically nothing I haven't tried, so I was sceptical as to what the "Gut Health Doctor" would be able to do for me. I've given up gluten and dairy, I hardly drink, I've had pints of blood tested, done acupuncture, taken supplements, had cameras enter my body from every which way and even suffered the indignity of pooing into a tray for three days before surrendering it to an unsuspecting courier, who transported my sample across London on the back of his bike.
I tell Dr Rossi this during our first appointment: that, if anything, my symptoms are getting worse with time; that I'm often bloated; very gassy; have had periods of violent vomiting (which subsided after a gastroenterologist put me on antidepressants); am regularly in pain; and riddled with food intolerances. I tell her that I have basically lost hope.
She replies with the air of a woman who has heard this a million times before, telling me that she understands my situation — even recounting the results of a recent study which found that on average IBS sufferers would give up 25 per cent of their remaining lives to live symptom-free. And then she gives me my instructions. I'm to follow the low-Fodmap diet, something I was advised first by my GP, but a more realistic version this time (thank God). The diet cuts out foods that are poorly absorbed by the body, the goal being that once the gut has had a chance to heal, you'll be able to reintroduce them. The full diet is a big undertaking, so I'm grateful for the "lite" approach. I also need new probiotics (Bio-Kult Advanced). And, critically, I have to practise mindfulness.
Rossi prescribed a gut yoga routine (also demonstrated in her book) as, according to a recent trial, yoga can have equal benefits to a low-Fodmap diet, with 87 per cent of participants reporting significant improvements in symptoms. Yoga helps manage the physical and psychological symptoms of stress (a big trigger for IBS), and I was to do it every morning, with 20 minutes of meditation in the afternoon, which has proven to be the most useful thing I've ever done for my gut health.
When I had flare-ups in the past, I would get angry with my body, and that's exactly what I was doing at the time of my three-week catch-up with Rossi. I was furious that after all my hard work I had nothing to show for it, and, as a chronic people pleaser, I was sure she would be disappointed. Instead she told me that getting frustrated with my body would only activate the vicious stress cycle and make my symptoms worse. She told me to be kinder to myself, something I hadn't tried before. And guess what? It worked.
Although I'm not "cured" (Rossi assures me that the full effects of mindfulness are not felt for 12 weeks), I am better. It turns out that the stress of the past five years — turning anyone with a nutrition degree upside down in my desperate search for answers, trying all the fads and all the while getting progressively more upset with my broken belly — was where many of my problems lay. After years of living with a condition that caused me physical pain and psychological torture with its ever-changing symptoms, I finally feel optimistic that I might one day be completely on top of the illness that has ruled my life for so long.
Rossi and her book (which should be prescribed to anyone diagnosed with IBS) taught me that while I can and will get better, it is a journey. She has not just given me useful tips — eat smaller portions, breathe from your stomach, wear loose-fitting clothes (don't need to ask me twice) — she has changed my understanding of my gut, my diet and my body as a whole. And thanks to her omnipresence in my life (hello, Instagram), I find myself feeling less alone with this condition than ever before.
• It's not fashionable, but fibre is your gut's best friend. Go for variety: different cereals, different types of nuts and lots of different fruit and veg. Eat that rainbow.
• If you're going to invest in a probiotic, make sure it's a multispecies one such as Symprove, VSL#3 or Vivomixx.
• If you have IBS, consider the lowFodmap diet (with a dietician's advice). High-Fodmap foods ( such as lentils, apples and garlic) produce gas that can cause pain and diarrhoea for those with IBS, an estimated 5 per cent of the population.
• Don't bother with detoxes, they're "hogwash", says Whelan, with not a single randomised controlled trial showing that they work.
• No need to join the one-meal-a-day brigade. There is no evidence that fastingdiets have any health benefits.
• Don't be too ready to ditch the gluten, as you'll miss out on beneficial nutrients that come alongside it such as fibre, vitamins and minerals. Your "gluten sensitivity" might be the "nocebo" effect — in that if you think it's causing you harm, you get those symptoms.
Written by: Fleur Britten
© The Times of London