The study found that children’s diet has a lifelong impact

Eating too much fat and sugar as a child can alter your microbiome for life, even if you learn to eat healthier later, suggests a new study in mice.

The study by researchers at UC Riverside is one of the first to show a significant decrease in the total number and diversity of intestinal bacteria in adult mice fed an unhealthy diet as a juvenile.

“We studied mice, but the effect we observed is equivalent to children having a Western diet, high in fat and sugar and their intestinal microbiome still being affected for up to six years after puberty,” explained UCR evolutionary physiologist Theodore Garland.

An article describing the study was recently published in Journal of Experimental Biology.

The microbiome refers to all bacteria, as well as fungi, parasites and viruses that live in a human or animal. Most of these microorganisms are found in the intestines and most of them are useful, stimulating the immune system, breaking down food and helping to synthesize essential vitamins.

In a healthy body, there is a balance between pathogenic and beneficial organisms. However, if the balance is disturbed, whether through the use of antibiotics, disease or an unhealthy diet, the body can become susceptible to disease.

In this study, Garland’s team looked for impacts on the microbiome after dividing their rats into four groups: half fed the standard “healthy” diet, half fed the “Western” less healthy diet, half with access to a racing wheel for exercise, and half without.

After three weeks on these diets, all of the mice returned to a standard diet and no exercise, which is usually how mice are kept in a laboratory. At the 14-week mark, the team examined the diversity and abundance of bacteria in the animals.

They found that the amount of bacteria like Muribaculum intestinale was significantly reduced in the Western diet group. This type of bacteria is involved in the metabolism of carbohydrates.

The analysis also showed that intestinal bacteria are sensitive to the amount of exercise that mice do. Muribaculum bacteria increased in rats fed a standard diet that had access to a running wheel and decreased in rats on a high-fat diet, whether they exercised or not.

The researchers believe that this species of bacteria, and the family of bacteria to which it belongs, may influence the amount of energy available to its host. The research continues on other functions that this type of bacteria can play.

Another noteworthy effect was the increase in highly similar bacterial species that were enriched after five weeks of treadmill training in a study by other researchers, suggesting that exercise alone can increase its presence.

Overall, UCR researchers found that the Western diet early in life had more lasting effects on the microbiome than exercise in early life.

Garland’s team would like to repeat this experiment and collect samples at additional times, to better understand when changes in the mice’s microbiomes first appear and whether they extend into later life.

Regardless of when the effects first appear, the researchers say it is significant that they have been observed for so long after changing the diet, and then changing it again.

The lesson, said Garland, is essentially: “You are not just what you eat, but what you ate as a child!”

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