Scientists from the University of Pittsburgh have found that excess sugar disrupts cells that regenerate the lining of the colon. Findings published in journals Cellular and Molecular Gastroenterology And hepatologyIt may help to understand why limiting sugary foods may improve symptoms in patients with inflammatory bowel disease (IBD).
Scientists divided the experimental mice into two groups: the first received a standard diet, and the second – a food high in sugar. The scientists then mimicked IBD symptoms by treating the animals with DSS, a compound that causes damage to the colon.
All mice on the high sugar diet died within nine days. In contrast, all animals fed the standard diet survived to the end of the 14-day experiment.
The team examined the animals’ colons to find out what made sugar so lethal for mice with IBD symptoms. This part of the intestine is covered with a layer of cells. In a healthy colon, these cells are constantly renewed by stem cell division. The update process normally takes five days.
Scientists have found that in some animals the protective layer of epithelial cells is completely lost, causing the colon to fill with blood and immune cells.
The researchers repeated the experiment in mice whose gut microbiota had been destroyed and got the same results. This means that sugar directly affects the colon and the effect is independent of gut microbes.
The team then tested how sugar affects mouse and human colonoids, miniature “guts” that can be grown in a laboratory dish. The scientists found that stem cells divide much more slowly in the presence of sugar. The metabolism of intestinal cells has also changed. They generally prefer to use fatty acids, but have switched almost entirely to sugar after growing in a high sugar environment.
Researchers suspect that this rearrangement inhibits stem cells’ ability to divide, slows the regeneration of colonic mucosa, and accelerates intestinal damage in IBD. These findings may help explain the findings of other studies that have linked sweetened beverages, including cola and fruit juices, to adverse outcomes for IBD patients.