Gut microbe study finds a possible cause of ulcerative colitis

By Nicholas Gerbis
Published: Monday, January 31, 2022 - 5:05am
Updated: Monday, January 31, 2022 - 8:12am

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Qiyun Zhu
ASU
Qiyun Zhu of the Biodesign Center for Fundamental and Applied Microbiomics.

Inflammatory bowel diseases like ulcerative colitis are on the rise and can lead to worse hospitalization outcomes for older patients. Current treatments target the symptoms, not the causes.

A new study in the journal Nature Microbiology might help change that.

"This is something that's really rare because, nowadays, it's very hard to find a new drug for things. And we were exploring a new approach," said co-author Qiyun Zhu, an assistant professor in ASU's School of Life Science.

Using a variety of molecular biology tools, the team found that many patients in their study had high levels of an enzyme made by a microbe called Bacteroides vulgatus.

"People don't know what it does; it's just a benign organism. But in this study, we find that, in certain circumstances, it can become a trouble, specifically when the body is out of nutrition, or other stressors," said Zhu.

The enzyme is a protease, a type of protein that can break down other proteins and provide energy to the body.

"However, if there are too many of these proteins, there could be trouble. Our body can be attacked by immune cells," said Zhu.

When researchers inhibited the enzyme in cells and in mice, the colitis subsided.

Conversely, when they transplanted feces with the enzymes into healthy mice, the rodents developed colitis.

Zhu says it's an exciting development, but it's just the beginning.

"We have yet to study the actual molecular mechanism. So far, what we find is that some stress factors of our body might induce the overproduction of this protein," he said.

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