Why the fiber in your traditional diet could be the most beneficial for your gut microbiota

Our overall health is linked to the gut and diet is the most powerful tool for shaping your gut microbiota,” states Liping Zhao, who we interviewed at the 8th Gut Microbiota for Health World Summit, in Miami.

In his lab, at the Department of Biochemistry and Microbiology at Rutgers University in New Jersey (USA), Professor Zhao and his team design pioneering dietary interventions, applying genomic tools to understand the impact of food on gut microbiota and how that can be used to improve human metabolic health. As part of their work, they have discovered how a high fiber diet can change the gut microbiome and thus benefit patients with type 2 diabetes.

According to Zhao, our gut works like a fermenter. Bacteria live in our gut and take nutrients from our diet every day. Any non-digestible or undigested dietary components will escape digestion through absorption and then become available to gut bacteria. That is why diet is so powerful, because it feeds nutrients to our gut microbiota.

Of all the dietary components, fiber is crucial. But, as Professor Zhao points out, it is not just any fiber; rather, it’s the fiber that is part of your traditional diet. In other words, the diet with which we have co-evolved for thousands of years.

If you are born in a Mediterranean country, better to keep your Mediterranean diet,” he says. Over generations, your family has been eating a traditional local diet, so the bacteria you take from your parents, and particularly from your mother, have been feeding on that same diet. That’s why our bacteria are most likely using the same nutrients.

The reason behind Professor Zhao’s assertion is that he has found there is a core group of bacteria that act like the foundation guild of gut health. And if we provide enough nutrients for this core group of bacteria—and avoid letting pathogenic bacteria grow—they will protect us and keep us healthy.

That is also why Zhao advises that if you move to a different country, for instance, you’d better watch out. If the new diet doesn’t have the necessary fiber to support your original foundation guild, this could cause a change in the core bacteria that provide the basis of gut health, leaving room for the gradual proliferation of pathogenic bacteria. And even remaining in the same country but enjoying everyday foods from other parts of the world can cause similar effects.

Moreover, it is not just what you eat, but also how you cook it. The way pasta and risotto are cooked al dente in the Mediterranean diet means the starch is less digestible and becomes a dietary fiber that promotes beneficial bacteria. As a result, explains Professor Zhao, “The way you cook will decide whether the nutrients are available to you or to your gut bacteria.”

 

Cristina Sáez
Cristina Sáez
Cristina Saez is a freelance science journalist. She works for several media, for instance the Spanish newspaper La Vanguardia, where she coordinates the science section, Big Vang; as well as research centres and scientific societies. She has been awarded for her journalistic work, among others, with the Boehringer Ingelheim Award in Medical Journalism 2015. Follow Cristina on Twitter @saez_cristina