5 Gut Health Myths, According To A Gut Health Doctor

5 Gut Health Myths, According To A Gut Health Doctor

Posted on: Myth Busters

If your gut is playing up, and you’re cutting out foods and swallowing supplements to calm it, read this

We have nothing but respect for dietitians. They’re the straight-talking nutritional experts who deal with people’s problems face to face. That also means they’re seeing first-hand the impact of inaccurate, misleading news reports and adverts.

“It’s the reason why I got into public engagement and social media,” says Dr Megan Rossi, dietitian, @theguthealthdoctor on Instagram and author of new book Eat Yourself Healthy. “Despite the amazing research being done, I had people coming to me saying that they were trying to look after their gut by taking high doses of different herbal supplements, which we know aren’t good for the gut. If you want good gut health, you certainly don’t have to take supplements. You should be able to do it through diet and lifestyle strategy.”

Rossi’s book has plenty of practical advice everyone can use, whether they have a digestive complaint or not, and the potential benefits of treating your gut well are pretty staggering. Improving your digestive system means you’ll be able to get even more goodness out of the food you eat and strengthen your immune system. Rossi also says a healthier collection of the microbes in our gut can improve things like mental health, heart health, kidney health – pretty much every organ in the human body.

It’s that last part especially that makes Rossi call the advances in understanding the gut a landmark scientific discovery, but she is quick to point out that “the commercialisation of the concept is well ahead of where we are scientifically”. To help you spot the snake oil and well-intentioned but misleading advice when you see it, we asked Rossi to detail the major myths she sees being pedalled.

Myth 1: Sugar Is Bad For Your Gut

“I hear this all the time,” says Rossi. “I hope one of the things the book will do is help people learn how the gut works, because a lot of people getting very fixated on what we put into our bodies but they typically have no idea what happens once we swallow it.

“When we eat sugar, it’s absorbed very high up in our intestine and most of the bacteria live in the lower part of the intestine, so the sugar doesn’t actually reach the bacteria.

“The thing is, we don’t want people to have heaps of added sugar, because that typically means a lot of processed foods that aren’t high in dietary fiber, which essentially is food for the good bacteria. Having some sugar in a treat every now and again is completely fine, as long as you’re still feeding bacteria with dietary fiber.”

Myth 2: Gluten Is Bad For Your Gut (With Apologies To Coeliacs)

Of course, gluten can cause a whole world of problems for a small minority, but avoiding it just in case brings its own risks you should be aware of. “People who cut gluten from their diet when they don’t have coeliac disease or an intolerance typically have a less diverse range of gut bacteria. If people cut gluten out, they’re often cutting out wholegrains, and the fiber from wholegrains is quite unique – it’s not something we can get and fruit and veg. So cutting out nutrients unnecessarily can have unexpected consequences.”

Myth 3: A Blood Test Can Identify A Food Intolerance

This was a new one on us, but it seems some companies offer a simple way of discovering if you have a food intolerance. Simple, but not reliable. “Tests where you send a blood sample away to diagnose a food intolerance are actually invalid. The only food intolerance you can diagnose through a test is lactose milk sugar intolerance, which is a breath test. Things like gluten intolerance and wheat intolerance, you can’t diagnose through a simple test.”

Rossi details the approach dietitians take in her book, dubbing it the three Rs: record, restrict and reintroduce. “You record what you eat and your symptoms,” says Rossi, “and you identify any associations. Step two is restriction – take it out of your diet to see if there’s a benefit. The third stage is to reintroduce it and that third step is really important to make sure that you are accurately determining the food tolerance.”

Myth 4: You Can Supplement Fiber

Thankfully, the message about eating more fiber is getting through, but it’s coming up against what Rossi describes as a tendency to look at food as a single nutrient. “People go, ‘We need fiber, let’s take a supplement’. Well, actually, there’s close to 100 different types of fiber, which is why we should be getting our fiber from the six different plant-based food groups: wholegrains, nuts, seeds, legumes, fruit and vegetables. Each category has got slightly differently-structured fiber that feeds different bacteria. If we want good gut health, we have to have a very diverse range of bacteria in our gut, and we achieve that simply by feeding our bacteria a diverse range of food.”

Myth 5: Popping A Probiotic Will Automatically Help

If you dive into Rossi’s book, you’ll quickly realise the science around the gut is complicated. Take probiotics: they’re good for your gut, sure, but it’s not as straightforward as you’d like. “The idea that probiotics are a panacea for all is very misleading,” says Rossi.

“We need to start thinking about probiotics like vitamins. If you have vitamin D deficiency, you’re not going to go and take an iron supplement and think that’ll fix your vitamin D deficiency. And it’s the same with probiotics. There are specific strains that show a benefit in specific situations.”

Written by Jonathan Shannon for Coach and legally licensed through the Matcha publisher network. Please direct all licensing questions to