In recent years, evidence regarding the importance of a healthy gut microbiome has popped up, largely in small-scale studies. Now, a new study adds more weight to the idea that

You are what lives inside you

The gut microbiome, as most researchers refer to it nowadays, is the totality of microorganisms present in the gastrointestinal tract. This gut flora, as it is sometimes called, is a big part of who you are. Many of these microorganisms have a mutualistic relationship with your body, benefitting you by fermenting dietary fiber and synthesizing several vitamins. In some regards, the gut flora behaves like an endocrine organ.

Just like other organs, however, the gut flora can change over time. Studies have shown that dysregulation is correlated with a host of inflammatory and autoimmune conditions, although researchers are still debating just how much of an impact this flora has on the human body.

The gut flora can also be influenced by what we eat. In the largest study of its kind, researchers from several countries analyzed how dietary habits and plant microbiomes are correlated. The bottom line: healthy, plant-based foods are linked with healthier microbiome.

“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 individuals’ microbiome, our research suggests that we may be able to modify our gut microbiome to optimize our health by choosing the best foods for our unique biology,” said Dr. Sarah Berry, Reader in Nutrition Sciences at King’s College London.

Eating for billions

The PREDICT 1 study is an international collaboration where researchers gathered data from 1,100 participants in the UK, including microbiome data, long-term dietary information, and results from hundreds of cardio-metabolic tests. The team looked for correlations between markers of health and microbiome — and they found them. Researchers found evidence that the microbiome is linked with specific foods and diets, and in turn, specificmicrobes in the gut are linked to biomarkers of metabolic disease. Surprisingly, the microbiome has a greater association to these markers than other factors, such as genetics, they note.

“We were surprised to see such large, clear groups of what we informally call ‘good’ and ‘bad’ microbes emerging from our analysis,” affirmed Nicola Segata, PhD, professor and principal investigator of the Computational Metagenomics Lab at the University of Trento, Italy and leader of the microbiome analysis in the study. “It is also exciting to see that microbiologists know so little about many of these microbes that they are not even named yet. This is now a big area of focus for us, as we believe they may open new insights in the future into how we could use the gut microbiome as a modifiable target to improve human metabolism and health.”

The most robust connection was between microbiome and obesity, but there was also correlation for cardiovascular disease and impaired glucose tolerance, which are key risk factors for COVID-19. These findings can lead to personalized diet plans, customized for everyone’s Researchers say these findings can be used to help create personalized eating plans designed specifically to improve one’s health.

So if you need extra motivation to eat healthy, don’t do it just for yourself — do it for the billions of microorganisms working tirelessly inside of you. As Professor Tim Spector, an epidemiologist from King’s College London and initiator PREDICT study initiator puts it:

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

The team now wants to release microbiome home tests to assess the internal microbiota.

“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,” says Spector. “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 personalized 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.”

However, it should be said that this is all still early stages of this type of research. For starters, a correlation doesn’t imply causation, and it’s not clear to what the microbiome itself is causing the conditions or whether they have a common cause, or are unrelated causally at all.

The follow-up projects, PREDICT 2 and PREDICT 3 are already ongoing, and they may help shed more light on it.

The study has been published in Nature Medicine.