Low-Fiber Diets Cause Depletion of Human Gut Bacteria, Study Finds

A diet low on fiber can deplete useful bacteria which in turn can have a snowball effect in the gut ecosystem where millions of other microorganisms that make it healthy might be driven to extinction.

In the study published in Nature, people with high fat, low-fiber diet have lower life spans than those who make it a point to eat high fiber foods. Additionally, when the numbers of a certain gut bacterium are below the recommended levels then those microorganisms may as well be extinct in the gut.

The intake of probiotic products such as yogurt could not get them back or restore it to once it was over time. Additionally, any disease that arise or get aggravated by gut bacteria depletion may take more than just yogurt or course of probiotics to manage it.

Diets like these are observed in majority of Western and industrialized societies. According to RD Mag, people who live in these places only have around 1/10th intake of daily recommended fibers compared to humans in other places.

"The reduced diversity of the gut microbiota in Western populations compared to that in populations living traditional lifestyles presents the question of which factors have driven microbiota change during modernization," the researchers wrote. "The reduced diversity of the gut microbiota in Western populations compared to that in populations living traditional lifestyles presents the question of which factors have driven microbiota change during modernization."

For their research, Stanford University scientists found that low-fiber diets, in mice whose guts have healthy communities of microbes, can reduce the number of species in it. They also found that the bacterium that has been depleted in mice guts were irreversible and are not seen in the third or fourth generations of their species. Additionally, a significant amount of mice who were returned to a high-fiber diet were never able to fully recover.

According to Dr. Justin Sonnenburg, lead author of the study, fiber is important to the human body even though we can't digest them. He said that it is the source of food for our gut bacteria.

"We would have difficulty living without them," he said, via a Stanford University press release. "They fend off pathogens, train our immune systems and even guide the development of our tissues."

However, it may be possible to reintroduce some of the depleted bacteria in the gut according to Sonnenburg. She recommends tweaking some "cultural practices" such as reducing the intake of too many antibiotics and not washing the hands immediately after petting dogs. Extreme practices would include transplanting fecal, but research and testing would be important to find out if it's necessary or would do more harm than good.