The PREDICT 1 international study, compiled by researchers from King’s College London, Harvard T.H. Chan School of Public Health, and health start-up ZOE, looked at data on participants’ gut microbiomes, their dietary habits, and other factors. The researchers discovered that certain microbes in the gut are linked to biomarkers of metabolic disease. Epidemiologist Tim Spector, who worked on the study, explains: “When you eat, you’re not just nourishing your body, you’re feeding the trillions of microbes that live inside your gut." Key highlights of the study show that:

There is a strong link between the foods we eat, the microbes in our gut, and our risk of developing conditions such as Type 2 diabetes and cardiovascular disease.Study participants who ate a diet rich in healthy plant-based foods were more likely to have higher levels of good bacteria in their gut, which in turn lowers their risk of developing health issues such as Type 2 diabetes.

Dr. Andrew T. Chan, Chief of Clinical and Translational Epidemiology Unit at Massachusetts General Hospital, said (opens in new tab) that the study, “demonstrates a clear association between specific microbial species in the gut, certain foods, and the risk of some common diseases. We hope to be able to use this information to help people avoid serious health problems by changing their diet to personalize their gut microbiome.”

Food, gut bacteria, and lowering Type 2 diabetes risk

A microbiome consists of trillions of microorganisms (microbes), both friendly and potentially harmful, including bacteria, fungi and viruses, found throughout the body but mostly in the small and large intestines. These microorganisms are involved with many vital processes, including stimulating our immune system, synthesizing specific vitamins, and protecting us from pathogens we ingest through food and water. The PREDICT 1 study analyzed data from 1,098 healthy adults in the US and UK, looking at their long-term diet information, gut bacteria analyzed from stool samples, and blood tests taken before and after eating. Researchers found evidence to suggest that plant-based diets cultivate healthy bacteria in the gut that helps to control blood sugar levels. Measuring blood glucose levels is a vital part of managing diabetes, and can be done at home using one of the best glucose meters (opens in new tab).  Two bacteria in particular were highlighted as playing a crucial role: Prevotella copri, and Blastocystis. Study participants with high levels of Prevotella copri had lower body fat, better blood sugar control, and good cardiovascular health. Researchers found that this bacteria was more common in those who consumed a diet rich in fish, nuts, seeds, and polyunsaturated fats. This latest study supports previous research (opens in new tab) showing that the food we eat, and the bacteria found in our digestive tract, plays an important role in body weight regulation, preventing metabolic syndrome, and lowering our Type 2 diabetes risk.

Which foods help lower your risk of Type 2 diabetes?

There’s already plenty of research (opens in new tab) that suggests a plant-based diet can protect against diabetes by promoting weight loss, improving your metabolic health, and increasing levels of healthy bacteria in the gut. Dr. Hana Kahleova, director of clinical research at the Physicians Committee for Responsible Medicine, says (opens in new tab) that, “eating a plant-based diet with ample fiber changes the gut microbiome composition for the better by feeding it the right kind of bacteria.” So what plant-based foods should you be filling your plate with? Researchers in the PREDICT 1 study found that participants who ate a diet rich in healthy plant-based foods, such as fruits, vegetables, whole grains, nuts, and seeds, had higher levels of good microbes and lower levels of bad microbes in their gut than participants who ate a diet high in processed plant-based foods. A separate study (opens in new tab), published last summer, showed that foods rich in Vitamin C could help lower your risk of developing diabetes, citing root vegetables, citrus fruits, fruit and vegetable juices, and tomatoes and other fruiting foods as the ones to focus on. Don’t fancy a completely plant-based diet? Don’t worry, research shows that a Mediterranean diet (opens in new tab) that includes lean proteins alongside plant-based foods can also reduce your risk of developing Type 2 diabetes. For further health and wellness content, take a look at our guides to the best health insurance companies (opens in new tab) and the best Medicare Part D plans (opens in new tab) to see how coverage could benefit you.

Major study reveals link between diabetes and gut health  and how to nourish yours - 69