Fiber and gut health: Study links low-fiber diet with leaky gut

There have been many studies that have gone over the many benefits of having a high-fiber diet, as far as improving and maintaining overall health is concerned. But just as having a high-fiber diet can yield many positives, having a low-fiber diet leaves one open to many negative consequences. Now, a recently conducted research on mice all but confirms this.

According to researchers from the University of Gothenburg, a low-fiber diet can lead to a swift increase in gut permeability, as well as changes in microbiota composition. This is based on data they gathered after studying mice that were fed a low-fiber diet in comparison with those who had a standard diet. The results of this study were published in Cell Host & Microbe.

A high-fiber diet can lead to many good things, for sure, but it’s not always achievable. This simple truth guided the researchers as they tried to find out what would happen in mice if they were fed a low-fiber diet over a period of a few days. As a report on the study states, the mice in the experiments were fed with a low-fiber, Western Style Diet (WSD) for eight straight weeks, and they ended up developing increased gut permeability. Meanwhile, other mice which were fed a standard chow diet for control didn’t show or encounter the same problems.

Another thing that the researchers found out was that all of the mice that were fed the low-fiber WSD diet showed a lower rate of gut mucous growth compared with the ones who were fed the standard control diet. In fact, there was a marked increase in the permeability of the mucous layer as well as reduced growth rate in as little as three days after the mice started on the low-fiber WSD.

According to Gunnar Hansson, “Low-fiber diets alter bacterial composition and influence what they produce. The result can be greater penetrability that affects the body’s cells.” He is commenting on the results of the study, which seem to confirm what other scientists have already known about gut bacteria and the importance of dietary fiber for it. “We clearly illustrated the rapid process by which the mucus layer responds to dietary modifications and subsequent bacterial changes,” he added.

One of the most surprising results of the research is the fact that, in the ensuing changes in microbiota composition as part of a low-fiber diet in mice, there was also a noticeable increase in numbers of Proteobacteria. These are a type of bacteria that have previously been linked with inflammation. That is obviously not something that you would want to happen inside your gut.

Professor Fredrik Backhed, a senior co-author of the study, says that the changes are pretty clear-cut: “Analysis of colonic mucosa-associated bacterial composition revealed a lower abundance of Bacteroidetes upon WSD feeding and a higher abundance of Proteobacteria.” And it was noted that the high abundance of Proteobacteria was mostly due to a bloom of the pathogenic genus Helicobacter.

Another change that didn’t go unnoticed was the rapid decrease in the proportion of the fiber-degrading bacteria Bifidobacterium. Another finding, which shows that a lack of fiber resulted in a lower amount of short-chain fatty acids (SCFAs) seems to suggest that the lowered abundance of Bifidobacterium was due to the low fiber in the diet as well. In any case, there are indeed many negative effects of a low-fiber diet, though the good thing is that it can be easily fixed by adding fiber, back into your daily diet.

Sources include:

NutraIngredients.com

ScienceDirect.com