We know that a poor diet can negatively impact the human body in all kinds of ways, and lately we're seeing a lot of research into how it can alter the gut microbiome. A team from University of California, Riverside (UCR) has explored the lingering effects of of a poor diet, demonstrating how unhealthy eating while young decreases the diversity of bacteria in the guts of mice over the longer term, even after a switch to a healthy diet.
The researchers set out to explore how shifts in the bacterial diversity of our gut microbiome during critical development periods in our lives can have long-lasting effects. To do so, the team enlisted juvenile mice which were split into four different groups. Half were placed on Western-style, high-fat, high-sugar diets, while the other half were placed on a standard healthy diet. Half of both of those groups were given access to a running wheel for exercise.
After three weeks, all of the rodents were then placed on a standard diet and given no exercise, and after 14 weeks, the scientists collected fecal samples from the mice and analyzed the diversity of their gut bacteria. They found that diversity was significantly reduced in those fed the Western diet during early age, as were bacterial species involved in carbohydrate metabolism.
The team’s investigations also revealed that physical activity appeared to play a role in the diversity of gut bacteria, showing that it was higher in the mice on a standard diet that had engaged in exercise. In the mice on the high-fat diet, however, the diversity was decreased whether or not that they had exercised.
Therefore, the authors conclude that diet during early life had more long-lasting effects on the microbiome than exercise. While the study was carried out on mice, the timeframes used by the researchers were made to mimic a key developmental period in humans.
“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.
Studies into the gut microbiome, what affects its diversity and how it can influence human health is a burgeoning area of research, and one that is turning up many fascinating insights. This includes how diet can impact the diversity of the gut microbiome and in turn things like heart disease and aging, but also how it is linked to neurological conditions such as Alzheimer’s and depression.
The authors of this new study describe it as one of the first demonstrating how juvenile diets can have long-lasting effects on the adult microbiome, “after a substantial washout period.” They hope to build on these findings by carrying out more experiments where samples are taken at more points in time, to better track when the alterations to the microbiome take shape and how they might stick around even later in life.
The research was published in the Journal of Experimental Biology.
