Gut expert Dr Megan Rossi suggests we should aim for 30 different types of plant foods each week.

Megan Rossi, PhD, aka ‘The Gut Doctor’, is a registered dietitian and a research fellow at King’s College London with a passion for gut health.

She explains why her new book Eat More, Live Well focuses on getting us to add more plants to our plates.

What is gut health? Why is gut health important?

“Gut health, namely the health of the trillions of bacteria living in our gut [the microbiome] is considered the biggest emerging area of research in medical and nutritional science [in] the past century, with studies linking a diverse gut microbiome with the lower risk of many diseases such as cancer, heart disease, liver disease, diabetes, asthma, depression and irritable bowel syndrome.

“The more diversity in your diet, the more diverse the nutrient supply for your gut microbes. Well fed, happy gut microbes equals a happier, healthier gut!

“This was the main driving force behind me writing Eat More, Live Well — to spread this landmark discovery beyond the research bubble and help as many people as possible.”

What is the role of gut health in weight loss?

“The gut-metabolism axis is a truly fascinating area. Our gut microbes, and the chemicals they make when they digest the fibre we eat from plants, can impact appetite.

“These chemicals essentially tell our body we’ve had enough. In turn, this halts the production of hunger hormones such as ghrelin, and increases the ‘I’m full’ hormones such as leptin.

“The gut–metabolism axis doesn’t stop there. Microbes and their metabolites have been linked with ‘turning on’ genes in your body that are related to fat distribution.

“In a nutshell, feed your [gut] well and it’s likely to keep everything else in check. So step off the scales [and] put down the calorie counting calculator.”

What triggered your interest in gut health?

“Losing my grandma to bowel cancer was my first trigger. But it was the hundreds of patients and clients, including elite athletes, that got me thinking about the systemic impact of the gut on the health of other organs such as our brain, kidneys and heart.

“This drove me to undertake a PhD in gut health, specifically looking at whether targeting the gut through the right nutrition can improve not just the health of the gut but other organs in our body too.”

What is the most common gut health issue in the UK?

“Functional gut disorders which present with symptoms such as constipation and bloating affect as many as 20% of the UK.

“But the importance of gut health goes well beyond gut symptoms to include immunity (with 70% of our immune system living in the gut), mental health and metabolic function.

“In fact, research has implicated gut health in the optimal functioning of pretty much every organ in our body.”

How can we eat enough plants?

“I’m all about quick and cost effective hacks to help people reach their diversity goals. It’s as simple as instead of just buying chickpeas, get the four-bean mix.

“Instead of just buying rice, get the seven-grain mix — both price matched examples [are] available from mainstream supermarkets.”

How does research back up your approach?

“Landmark research by McDonald et al [was] the first to demonstrate the importance of plant diversity on gut health.

“They demonstrated that those who eat 30 different types of plants each week have better gut health than those who eat only 10, and plant diversity was a better predictor of gut health compared to being vegan, i.e. 100% plant based.”


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