Even foods from the same "pyramidal" group act differently on intestinal bacteria

A new small study reveals that spinach and carrots are rich in vitamin A, fiber and potassium, but that does not mean that they have the same effect on our intestinal microbiomes.

We tend to think of foods in terms of general categories of the food pyramid: fruits, vegetables, meats, dairy products, etc.

But researchers say that the way the foods we eat affect specific strains of intestinal microbes can vary greatly from one fruit to another or from one vegetable to the other.

Leafy vegetables such as kale and spinach can promote a bacterial species, but carrots and celery could promote another, even if they all belong to the same category in the food pyramid.

The team at the University of Minnesota says its study shows that it is not enough to look at nutrition labels and that future food-based interventions to regulate intestinal bacteria may need to be addressed. adapted to each individual.

"Nutritional labels are written for humans," Dr. Dan Knights, senior author of the Department of Computer Science and Engineering at the University of Minnesota, senior author, told DailyMail.com.

"And we do not have the right way to measure what different types of foods contain, and microbes worry about the exact chemical composition."

For the study, published in the journal Cell Host & Microbe, the team recruited 34 people, who recorded everything they ate for 17 days.

The researchers collected stool samples every day to see how microbiomes were changing day by day.

They found that foods had similar effects on the gut microbiome when they were divided into subcategories rather than into broad categories such as products, meat, dairy products, and so on.

For example, leafy green vegetables like kale and spinach had similar influences on the microbiome.

But it was very different from the effects of vegetables like carrots or fruits like tomatoes, despite the fact that they contain similar nutrients like calcium, fiber and vitamin C.

Intuitively, the researchers thought that two people with exactly the same diet would have the same patterns of intestinal microbes.

As a result, two of the 34 subjects in the study only ate Soylent, a meal replacement, for the 17 days of the study.

The researchers found that even the microbiome of these subjects varied from day to day, suggesting that a repetitive diet might not stabilize intestinal bacteria.

"We expected that by doing this dense sampling – where you can see what people ate each day and what happened to their microbiome – we would be able to correlate the nutrients with food." specific strains of microbes, "said Dr. Knights in a press release.

"But what we discovered did not match the strong associations we expected. We had to scratch our heads and propose a new approach to measure and compare different foods. & # 39;

The results of the study suggest that when doctors prescribe a diet to stimulate or suppress a type of bacterial species they may need to adapt meal plans to each person with whom they work.

"The microbiome has been associated with a wide range of human conditions, including metabolic disorders, autoimmune diseases, and infections. There is therefore a strong motivation to manipulate the microbiome with a diet as a means of influencing health, "said Dr. Knights.

"This study suggests that it's more complicated than just looking at food components like fiber and sugar.

"There is still a lot of research needed to understand how the full range of nutrients in food affects how the microbiome responds to what we eat."