Professor Tim Spector has presented his work on the unexplained missing link between genetics and disease – the human microbiome – to worldwide audiences. His appearance in Bath this month, in conversation with presenter Gaby Roslin, will give fascinating insights into transforming everyday meals into gut-friendly, health-promoting experiences, says Emma Clegg.
When you talk to an award-winning epidemiologist, doctor and science writer who is working on the relationship between nutrition, the gut microbiome and health, then asking what he had for breakfast is all par for the course.
Tim Spector told me on the day I spoke to him that he had eaten breakfast at midday, when he had an M&S Food X ZOE Gut Shot with a handful of berries. He passes it off as a snatched ‘breakfast on the go’, but it has impact because the gut shot is packed with over five-billion live cultures from 14 strains of bacteria, and is high in fibre. It’s also produced by ZOE, the science and nutrition company that Tim co-founded in 2017.
Tim is a Professor of Epidemiology at King’s College London. Recognised for his impactful work during the pandemic, he has been at the forefront of groundbreaking discussions on health and diet. His research emphasises the importance of gut health, the benefits of eating a variety of plants weekly, and how diet can influence health even more than genetics.
For Tim it all started with his work at King’s College on the world’s largest identical twins study, TwinsUK. “I became interested in genetics in about 1992, thinking that it was really the main driver of everything. From that point I didn’t find any differences between identical twins until a moment in 2011 when we measured the microbiome for the first time. When we got the first results, we saw how different the gut microbes were in identical twins, which was the first thing we’d ever found different in twins that we couldn’t explain. So this was definitely a eureka moment, because if identical twins had different microbes, it could explain why they get different diseases.”
As he continued his research, there were two key findings. Firstly that genes only play a small part in which microbes you’ve got. Secondly that there are links between metabolic diseases such as obesity and having poor gut health and low gut microbial diversity.
After Tim set up ZOE in 2017 with co-founders Jonathan Wolf and George Hadjigeorgiou, they used it to help them understand individual responses to food in the real world by enabling scientific research at an unprecedented scale with remote trials conducted by people in their homes. Then during the pandemic, Tim used community science and an app to understand the symptoms of Covid-19 in millions of people, for which he received an OBE. after more studies the team refocused their efforts around personalised health.
“By combining our latest science with the results of thousands of our members’ at-home tests, ZOE now has a programme that helps people make smarter food choices for their long-term health”, says Tim.
Tim is the author of bestselling books such as The Diet Myth (2020), Spoon-Fed (2022), and Food for Life: Your Guide to the New Science of Eating Well (2024). His latest book The Food for Life Cookbook (2024) provides a guide to a healthy life with food, featuring 100 recipes created in collaboration with ZOE’s nutritionists. The approach focuses on abundance rather than restriction, helping people make practical, enjoyable food choices to boost energy, longevity and overall health.
The 100 recipes are designed to fit with the six principles of the ZOE approach: to eat 30 plants a week; to eat the rainbow; to use a variety of plant-based proteins; to think quality, not calories; to minimise ultra-processed foods; to incorporate fermented foods; and also to introduce time-restricted eating, which allows your gut time to rest.
“Following the six principles we wanted to share, we chose recipes that showcased more diverse plants, more colour, more fermented foods and more plant protein. We also wanted the recipes to be easy to cook, not expensive, and attractive both to look at and to taste”, says Tim.
Thirty plants a week might feel unachievable, but in fact this includes vegetables, fruits, grains, nuts, seeds, herbs and spices, so it isn’t hard to achieve if you are cooking regular healthy meals – and a single ‘plant’ can be as simple as a sprinkling of herbs or a handful of seeds.
“We are fairly liberal in what we count as a plant, because every one has different chemicals. We know that our microbes are super fussy, so just a slight change in the diet and a slightly different plant, even in the same family, will feed a whole new set of microbes. That’s why this diversity is important”, says Tim.
Avoiding highly processed foods underpins the food philosophy. Tim explains, “We used to think it was the amount of fat and sugar in highly processed foods that were bad and everything else was fine. And that’s what the food companies wanted us to think, because then they could reformulate it and fiddle around with the chemicals to get less fat or less sugar. But it turns out that’s only one bit of the picture – the other is that the food is soft and baby-like, you don’t have to chew it, you can eat it two or three times as fast as normal food, it doesn’t contain fibre or any other nutrients, and it also contains many chemicals which are harmful to your gut microbes.”
When it comes to meat, Tim says that processed meat should absolutely be avoided: “I have meat once or twice a month. There’s no doubt that processed meats are harmful for your health – hams, salami and most sausages are highly processed, so you need to limit your intake. Eating a small amount of high-quality meat is what we should be aiming for, and we shouldn’t be having meat with every meal.
“We’ve just done a study comparing vegans, vegetarians and meat-eaters, and it shows that actually the healthiest people with the most diverse microbes are those that eat a small amount of meat, but they also have a ton of vegetables and plants in their diet – that’s because meat provides some diversity. I would say that eating meat in moderation is probably the best way to do it.”
Advancing technology has dramatically informed Tim’s research around gut microbes, and has also exposed the rudimentary studies of the past. “Twenty years ago we were only looking at 1% of all the microbes that exist in our guts, and that’s why we didn’t really have a full picture of what we were seeing, because we focused on the ones that cause disease. The others we misnamed, calling them ‘commensals’ [an organism that benefits from another organism without harming or benefitting it], and they were just ignored. It’s only in the last five to ten years that this has really scaled up.
“This area shows science evolving at speed and depth; what’s exciting for me is that I’ve now been able to connect the dots between my scientific work, my personal discoveries in how to eat to feel good and my long-term mission to share this knowledge widely.”
There is plenty more to investigate about the gut microbiome, however, asserts Tim. “We have just scraped the surface really, and have found that it takes really big numbers to make meaningful discoveries, a bit like genetics. We used to think we could get useful results by testing a few hundred people, but it turns out that you need to be dealing with hundreds of thousands of people, because everyone is so different.”
The production of food is also very much on Tim’s agenda. “Nowadays we need to look at food through three lenses: health, ethics and environment. And there’s no doubt that the most important decision you can make for the planet is through your food, not not through whether you drive a car or not.
“My book is an education through recipes about how people can eat more healthily. There’s nothing quite like a picture in a book to demonstrate this, and at the same time you can see how easy it is, with recipes that have so much more fibre and protein than more traditional options.”
Presenter Gaby Roslin will be in conversation with Professor Tim Spector on 28 January at The Forum at 7.30pm–8.30pm. bathfestivals.org.uk
The University of Bath: bath.ac.uk
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The Food for Life Cookbook: 100+ recipes created with ZOE, by Tim Spector, Jonathan Cape, £28, with photography by Issy Croker
Presenter Gaby Roslin will be in conversation with Professor Tim Spector on 28 January at The Forum at 7.30pm–8.30pm. bathfestivals.org.uk