Fiber and intestinal flora have a huge impact – healing exercise

Although IBD tends to run in families, diet and intestinal flora also play an important role. A low-fiber diet increases special bacteria that break down the intestinal mucosa and promote inflammatory bowel diseases.

In a new study in which experts from University of Michigan Investigate potential mechanisms by which diet and gut bacteria, combined with genetics, may promote inflammatory bowel disease. The results are published in the specialized journal.Cell host and microbeTo read.

Effect of diet and intestinal flora

Although it is already known that inflammatory bowel disease (IBD) has a genetic component, not all people with a family history of the condition develop the disease. This shows that other factors play a role as well, the researchers explain.

It is therefore assumed that diet and intestinal flora also have an important influence on the development of inflammatory bowel diseases. The new study aims to identify possible underlying mechanisms.

A very complex interaction

In fact, the team discovered a very complex interplay between diet, genes and gut flora, which could explain why IBD occurs.

The new research builds on previous studies that showed that a low-fiber diet contributes to the proliferation of bacteria that feed on intestinal mucus.

Genetic loss of a protein called interleukin 10 (IL-10), which affects the immune system, or its receptor, can lead to early onset of inflammatory bowel disease in infants and children, researchers report.

A low-fiber diet increases the risk

Using mice with the same immune changes, the team has now examined the effect of gut flora and diet on disease risk. The researchers explained that some animals spontaneously developed inflammation in the intestines, but its severity varied and it seemed to be exacerbated by the presence of certain bacteria and a low-fiber diet.

The team found that mice raised without bacteria showed no signs of inflammatory bowel disease. By adjusting for the presence or absence of the model human gut microbiome and the fiber content of the diet, the researchers were able to increase or decrease inflammation.

Contact with intestinal bacteria

Experts also found that inflammation caused by a low-fiber diet appears to increase in response to the increased presence of mucus-breaking bacteria Akkermansia mucinphila and Bacteroides caccae.

“These bacteria begin to search for nutrients in the mucous layer, reducing its thickness and its function as a barrier, bringing the microbes closer to the host tissue by only 10-100 micrometers. In mice with IBD genes, this was enough to cause the disease“, says study author Professor Dr. Erik Martens in one press release.

Fiber against inflammation?

On the other hand, if mice receive a high-fiber diet, this prevents inflammation. According to the team, when the animals were switched from a low-fiber diet to a high-fiber diet, there was a peak in inflammation, followed by a significant decrease.

According to experts, this suggests that fiber could reverse the harmful effect of mucus erosion on inflammation. However, IBD is often treated with a so-called exclusive enteral diet, which does not contain fiber.

Despite the lack of fibre, this treatment leads to reduced inflammation in humans for reasons that are still unclear, the team reported.

Isobutyrate suppresses inflammation

In further experiments on mice, the team finally identified branched-chain fatty acid isobutyrate. This was present in increased amounts in animals that received enteral feeding and suppressed inflammation. Isobutyrate is produced by fermentation of certain bacteria in the intestines.

“It appears that one way this exclusive enteral nutrition may work in humans is by stimulating certain bacteria to produce beneficial metabolites“, says Professor Dr. Martens.

Further studies will now investigate how diet and bacteria interact to improve treatments for inflammatory bowel diseases and learn how the onset of these diseases can be prevented by addressing the causative factors. (like)