Study: Plant-Based Foods Feed Gut Microbes Linked To Lower Rates Of Diabetes, Heart Disease & Obesity

Plant-based diets help feed gut microbes that are associated with lower risks for heart disease, obesity and diabetes, a new large-scale study finds. The paper adds to the growing base of scientific evidence showcasing the health benefits linked to diets rich in healthy plant-based foods. 

The study, published in Nature Medicine, was led by a team of international scientists from Harvard-affiliated Massachusetts General Hospital (MGH), King’s College London (KCL), University of Trento in Italy, and health science startup ZOE. Researchers applied metagenomics and cardiometabolic blood chemical profiling techniques to examine fifteen gut microbes that have previously been shown to be connected to common diseases. 

Representing one of the most comprehensive and detailed large-scale studies into the link between gut microbes and diet, the authors concluded people who ate diets rich in healthy plant-based whole foods were more likely to have an abundance of specific microbes that are associated with lower risk of developing obesity, Type 2 diabetes and cardiovascular disease. 

“This study demonstrates a clear association between specific microbial species in the gut, certain foods, and risk of some common diseases,” senior co-author Andrew T. Chan of MGH and a professor of medicine at Harvard Medical School told the Harvard Gazette. 

In addition, the researchers find that the microbiome has a stronger greater association with metabolic biomarkers of disease than other factors, such as genetics, suggesting that changing our diets could have a profound impact on our likelihood of developing illnesses. 

This study demonstrates a clear association between specific microbial species in the gut, certain foods, and risk of some common diseases.

Andrew T. Chan, Senior Co-Author, MGH & Harvard Medical School

“We hope to be able to use this information to help people avoid serious health problems by changing their diet to personalise their gut microbiome,” said Chan. 

“When you eat, you’re not just nourishing your body, you’re feeding the trillions of microbes that live inside your gut,” added Tim Spector, epidemiologist King’s College London, who started this international collaborative research dubbed the PREDICT study, which plans to use the data to develop an individualised and personalised preventative medical tool under the startup ZOE.

In total, the study involved more than 1,100 participants in the U.S. and U.K. and tracked detailed long-term dietary information. While studying the connection between diet and disease is complicated because of the enormous individual variation in people’s diets and how they change over time, the authors believe that the number of participants and the in-depth information collected gives greater weight to their study. 

Among the specific microbiome species that the researchers looked at was Prevotella copri and Blastocystis, both of which are linked to having favourable blood sugar levels after meals, while other species were associated with reduced levels of blood fats and inflammation markers after eating. 

When you eat, you’re not just nourishing your body, you’re feeding the trillions of microbes that live inside your gut.

Tim Spector, Epidemiologist, KCL

“We were surprised to see such large, clear groups of ‘good’ and ‘bad’ microbes emerging from our analysis,” said Nicola Segata, professor and principal investigator of the Computational Metagenomics Lab at the University of Trento. 

While there is still much to be explored in the realm of gut microbes, the latest study adds to the plethora of scientific evidence showing the health benefits of eating a plant-based diet. Scientists have previously found that high intake of protein from plants such as legumes, whole grains and nuts is linked to lower risk of developing a number of diseases, including diabetes, heart disease and stroke, in a paper published in the British Medical Journal. 

Another study, led by National Cancer Institute in the U.S., found an “inverse association” between higher consumption of plant-based foods and heart disease mortality rates. The most prominent inverse associations were recorded in the replacement of eggs and red meat with plant proteins. 

In addition to supporting human health, plant-based proteins are also more environmentally-friendly. An Oxford University 2019 study found that healthy plant-based foods are almost always associated with a smaller carbon footprint.

Lead image courtesy of Ella Olsson via Flickr.