Diets rich in certain plant-based foods are linked to gut microbes that are associated with a lower risk of developing conditions such as obesity, type 2 diabetes and cardiovascular disease, new research suggests.

Scientists say the study indicates people may be able to modify their gut microbiome – genetic material of all microbes like bacteria, fungi, protozoa and viruses – to optimise their health by choosing the best foods for their unique biology.

The findings could be used to provide personalised dietary advice for better health, based on gut microbiome testing.

Dr Sarah Berry, reader in nutrition sciences at King’s College London, said: “As a nutritional scientist, finding novel microbes that are linked to specific foods, as well as metabolic health, is exciting.

“Given the highly personalised composition of each individual’s microbiome, our research suggests that we may be able to modify our gut microbiome to optimise our health by choosing the best foods for our unique biology.”

The Predict 1 study analysed data on the composition of participants’ gut microbiomes, their dietary habits, and cardiometabolic blood biomarkers.

Researchers found evidence that microbiome is linked with specific foods and diets, and that certain microbes in the gut are linked to biomarkers of metabolic disease.

They say that the microbiome has a greater association to these markers than other factors, such as genetics.

The study published in Nature Medicine found that having a microbiome rich in Prevotella copri and Blastocystis species was associated with maintaining a favourable blood sugar level after a meal.

Other species were linked to lower post-meal levels of blood fats and markers of inflammation.

Some of the identified microbes are so novel that they have not yet been named.

Professor Tim Spector, an epidemiologist from King’s College London, who started the Predict study and is scientific founder of science start-up company ZOE, said: “When you eat, you’re not just nourishing your body, you’re feeding the trillions of microbes that live inside your gut.”

Researchers discovered the makeup of someone’s gut microbiome was strongly associated with specific nutrients, foods, food groups and overall diet composition.

They found robust microbiome-based biomarkers of obesity, as well as markers for cardiovascular disease and impaired glucose tolerance, which are key risk factors for Covid-19.

Prof Spector added: “I am very excited that we have been able to translate this cutting edge science into an at-home test in the time it has taken for the research to be peer reviewed and published.

“Through ZOE, we can now offer the public an opportunity to discover which of these microbes they have living in their gut.

“After taking ZOE’s at-home test, participants will receive personalised recommendations for what to eat, based on comparing their results with the thousands of participants in the Predict studies.

“By using machine learning, we can then share with you our calculations of how your body will respond to any food, in real-time through an app.”

The study found that subjects who ate a diet rich in healthy, plant-based foods were more likely to have high levels of what they called good gut microbes.

However, diets containing more highly processed plant-based foods were more likely to be associated with bad gut microbes.

Nicola Segata, professor and principal investigator of the Computational Metagenomics Lab at the University of Trento, Italy, was the leader of the microbiome analysis in the study.

She said: “We were surprised to see such large, clear groups of what we informally call ‘good’ and ‘bad’ microbes emerging from our analysis.”

Predict 1 looked at links between diet, the microbiome, and biomarkers of cardiometabolic health.

Researchers gathered microbiome sequence data, detailed long-term dietary information, and results of hundreds of cardiometabolic blood markers from more than 1,100 participants in the UK and the US.

Predict 2 completed its primary investigations in 2020 with a further 1,000 US participants, and Predict 3 launched a few months ago.