What You Eat Shapes The Germs In Your Guts : Shots - Health News Compared with kids in Burkino Faso, those in Florence, Italy, have far less variety in the bacteria that live in their digestive tracts. Researchers say the difference lies in the Italian kids' high-fat, low-fiber diet.
NPR logo What You Eat Shapes The Germs In Your Guts

What You Eat Shapes The Germs In Your Guts

Bacteria get a bad rap for finding their way into our lettuce and hamburgers and making people sick. But there are bacteria percolating in our tummies that do plenty of good. They help us digest our food and avoid certain illnesses.

Diet may contribute to what bacteria are living in your gut. iStockphoto.com hide caption

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Diet may contribute to what bacteria are living in your gut.


Not all tummy ecosystems are the same, however. In fact, a study out of Europe found differences between the bacteria in the digestive tracts of Italian children and those living in a rural village in Africa.

How come? Researchers say the reason may be what the kids eat. The Italian children eat far more processed food: high-sugar, high-fat and low-fiber. The African children consumed more fiber and generally had diets richer in plants.

Dr. Paolo Lionetti, a pediatric gastroenterologist at Meyer Children Hospital at the University of Florence and a study co-author, says those differences could help explain the increase in certain diseases that have become more common in the developed world.

"We live in a clean environment in the Western countries," Lionetti says. "But we have a lot of allergies and obese children, and inflammatory bowel disease, autoimmunity diseases that we don't have in Africa in this region.  So, we have lost -- maybe [because of] a change in the diet -- healthy bacteria that can protect our guts and our organs from these bad conditions."

The results appear in the Proceedings of the National Academy of Sciences.

To be sure, this is a small study. The researchers compared the stools of 15 children in Florence, Italy, with those of 14 children in Burkina Faso. The bacteria in the stools of African children were more varied and had a smaller proportion of microbes associated with obesity. However, the bacterial makeup in the guts of children who were still breastfeeding in both countries was similar.

"Our results suggest that diet has a dominant role over other possible variables such as ethnicity, sanitation, hygiene, geography, and climate, in shaping the gut microbiota," wrote the study authors.

Researchers chose Burkina Faso as a research location because Meyer Children Hospital and the Tuscany region have a cooperation program with a hospital in that African country.

Previous research has shown certain types of bacteria are linked to obesity, asthma, ulcers and certain allergies.  The PNAS study is the latest in a growing body of research showing that what lives in our guts is linked to what we eat.

Lionetti says the research team is working on the next step of the research, which is to collect stools from children in African cities and characterize the microbes found.