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You Are What You Eat: Heart Health and More Linked to Gut Microbiome

gut microbes

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Key Takeaways

  • The gut is full of microbes that live in the gastrointestinal tract and play numerous roles in keeping us healthy.
  • A team of international researchers recently found that the microbiome was unique to the individual and not predetermined by genes.
  • Therefore, positive dietary changes can improve gut health and help reduce the risk of health conditions like obesity and Type 2 diabetes.

If you eat a diet rich in the right foods, your gut will reap the benefits and you’ll have a lower risk of developing health conditions like obesity, Type 2 diabetes, and cardiovascular disease.

At least, that’s according to a new, large-scale international study that cited researchers from more than 10 institutions, including the Harvard T.H. Chan School of Public Health, Massachusetts General Hospital, King’s College London, and a health startup in the U.K. called ZOE. 

The findings, published in the journal Nature Medicine, suggest that due to the personalized nature of the microbiome, a personalized approach to what you eat for your unique biology is the best way to positively impact your health. 

The Study In Detail

Researchers used metagenomics (the study of genetic material) and blood chemical profiling techniques to analyze the dietary habits of 1,098 individuals enrolled in a trial called PREDICT 1. They also looked at molecular markers (biomarkers) of metabolic and heart health in the participants’ blood samples, extracted either following a short period of fasting or after mealtimes.

Dr. Sarah Berry

We discovered that the microbiome was unique to each individual and not predetermined by our genes. Therefore, there is great potential to modify our microbiome through diet to positively impact our health.

— Dr. Sarah Berry

This enabled them to identify a panel of 15 gut microbes associated with lower risks for several common diseases; they also uncovered 15 gut microbes associated with higher risks. The study revealed associations between gut bacteria and biomarkers of obesity, cardiovascular disease, and impaired glucose metabolism. 

“These microbes can be split into a group of ‘good microbes,’ which are associated with healthy foods and dietary patterns and measures of good health, including lower body fat, lower inflammation, lower blood pressure, lower blood lipids, and much more,” says study co-author Dr. Sarah Berry, a senior lecturer in the department of nutritional sciences at King’s College London. 

What Is the Gut Microbiome, Exactly? 

The gut microbiome is made up of microbes, bacteria mostly, which are largely present in our gastrointestinal tract and play numerous roles in keeping us healthy.

“The microbiome keeps inflammation down by inhibiting the growth of other harmful bacteria, prevents toxins entering our circulation, aids with proper digestion, and contributes to immune system function and the absorption of nutrients, to name just a few of its functions,” says Tejal Pathak, a clinical dietitian, diabetes educator, and practitioner based in Houston, Texas.  

The researchers found that quality was instrumental when it came to separating “good” bugs from “bad” bugs. “For example, not all plant foods are associated with favorable microbes; highly processed plant foods are actually associated with unfavorable microbes,” Dr. Berry notes.

“The same is true for animal foods. Some animal foods (such as oily fish) are associated with the favorable microbiome and others (processed red meat) are associated with the unfavorable microbiome.” 

Tejal Pathak, RD

The microbiome keeps inflammation down by inhibiting the growth of other harmful bacteria, prevents toxins from entering our circulation, aids with proper digestion, and contributes to immune system function and the absorption of nutrients.

— Tejal Pathak, RD

Dr. Berry says this is what makes the study so novel. “We have unraveled a healthy and unhealthy microbiome signature associated with both diet and health within the same study,” she explains. “We also discovered that the microbiome was unique to each individual and not predetermined by our genes. Therefore, there is great potential to modify our microbiome through diet to positively impact our health.”

Eating For a Healthy Gut

There are various pillars in the gut-healthy diet. First of all, it’s important to have balance. Pathak says this means whole foods, fruits, and vegetables throughout the day. Drinking water and avoiding refined sugars is also key to prevent imbalance in the gut microbiome.

“Meals with prebiotics and probiotics together could create a happy place for the gut microbiome,” Pathak adds. “For instance, add sauerkraut and/or kimchi to your salads, top your yogurt with banana, eat overnight oats with yogurt and berries or a kefir smoothie with berries.” Other examples of prebiotic foods are asparagus, artichokes, onion, garlic, leeks, and bran. 

“Just like us, our healthy gut bacteria can be picky when it comes to the type of prebiotic fiber they thrive on,” Pathak explains. “‘So it’s good practice to include a variety of fruits and vegetables.” 

What This Means for You


It's important to be aware of your gut health because it relates to so many aspects of our wellbeing, but there is no one size fits all diet for a healthy microbiome. If you're having GI issues or concerns, be sure to consult your doctor or registered dietitian before making any major dietary changes. 

The Research Has Only Just Begun

Dr. Berry says their series of PREDICT studies provides the richest dataset in the world on individual responses to food. “The depth, breadth, and scale of the data that we have allows us to explore new questions as they arise from each piece of analysis in real time," she says. "For example we are finding that time of day and meal sequence are important so we are now exploring that.”

Research also is underway into the associations between the food and the microbiome. “Ultimately, we plan to launch a randomized controlled trial to demonstrate the efficacy of the ZOE scores,” Berry says. “The ZOE scores are the culmination of this scientific research and allow the research to be translated into actionable, personalized advice to enhance health.” 

While the research shows a strong relationship between food, the microbiome, and health, Dr. Berry says there are many factors that determine how we respond to the foods we eat. These include not only what we eat, but how we eat (taking into account the time of day, sleep, and exercise) and our genetics. “Microbiome testing alongside the measurement of other determinants of our responses to food will enable a truly personalized approach to nutrition,” Dr. Berry says. 

There’s no “one size fits all” with the gut microbiome, Pathak says. If it’s seriously out of whack, a number of gastrointestinal (GI) issues can occur, and treatment involves ensuring different strains of gut bacteria are at the right level. For instance, saccharomyces boulardii relieves digestive disorders and c. difficile infection, and lactobacillus rhamnosus shortens the duration of gastroenteritis, Pathak explains.

“If someone is having GI issues or concerns, it’s best to work with their doctor and a registered dietitian to restore balance with gut microbiota and keep the disease state under control,” she adds. 

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  1. Asnicar F et al. Microbiome connections with host metabolism and habitual diet from 1,098 deeply phenotyped individuals. Nature Medicine. 2021 Jan. doi:10.1038/s41591-020-01183-8