Eating too much fat and sugar as a child can change your gut microbiome for life, even if you later learn to eat healthier.
The analysis by UC Riverside researchers is one of the first to reveal a significant decrease in the entire number and diversity of gut bacteria in older mice fed an unhealthy diet as juveniles.
“We studied mice, but the effect we observed is equivalent to kids having a Western diet, high in fat and sugar and their gut microbiome still being affected up to six years after puberty,” explained UCR evolutionary physiologist Theodore Garland.
A paper describing the analysis has been published in the Journal of Chemical Biology.
The gut microbiome refers to all the bacteria in addition to fungi, parasites, and viruses that reside on and inside a human or animal. Most of these microorganisms are present in the intestines, and most of them are helpful, stimulating the immune system, breaking food down and helping synthesize key vitamins.
In a healthy body, there’s a balance of pathogenic and valuable organisms. But if the balance is disturbed, either via the use of antibiotics, sickness, or poor diet, the body may become vulnerable to illness.
In this analysis, Garland’s team looked for impacts on the gut microbiome after dividing their mice into four groups: half fed the regular, ‘healthy’ diet, half fed the healthy ‘western’ diet, half using a running wheel for exercise, and half did not.
Following three months spent on these diets, all mice were returned to a regular diet and no exercise, and this is normally the way mice have been stored in a laboratory. At the 14-week mark, the group analyzed the diversity and abundance of bacteria in the animals.
They found that the amount of bacteria such as Muribaculum Intestinale was considerably reduced in the Western diet group. This type of bacteria is involved in carbohydrate metabolism.
Analysis also revealed that the gut microbiome is sensitive to the amount of exercise the mice obtained. Muribaculum bacteria increased in mice fed a normal diet that had access to a running wheel and diminished in mice onto a high-fat diet whether they had exercise or not.
Researchers believe this species of bacteria, and the household of bacteria that it belongs to, might influence the quantity of energy available to its host. Research continues into other purposes this type of bacteria might have.
One other effect of note was the increase at an extremely similar bacteria species which were improved following five weeks of treadmill training in a study from other researchers, implying that exercise alone might increase its existence.
Overall, the UCR researchers found that early-life western diet had more long-lasting effects on the microbiome than did early-life exercise.
Garland’s team would like to replicate this experiment and choose samples at other points in time, to understand when the changes in mouse gut microbiomes first appear, and whether they expand into later phases of life.
Regardless of when the effects first seem, nevertheless, the researchers say it is important that they were observed so long after altering the diet, and then changing it back.
The takeaway, Garland stated, is basically, “You are not only what you eat, but what you ate as a child!”
Related Journal Article: https://jeb.biologists.org/content/early/2021/01/10/jeb.239699