Intestines Sketch with Guts Bacteria

(© T. L. Furrer -

DAVIS, Calif. — Mixing hydrogen peroxide with hair is an age-old combination. Mixing hydrogen peroxide with the insides of the human body? That’s a dangerous combination many health experts recommend avoiding. While scientists have believed the disinfectant is best kept out of the body, a new study finds you may actually be making your own hydrogen peroxide (H2O2) to promote gut health.

Researchers from the University of California-Davis reveal an enzyme in the lining of the colon releases H2O2 to protect gut microbes. Their results are shedding new light on how the body organizes microorganisms in the gut and may lead to a new treatment for inflammation.

The team says most of the body’s microbes live in the large intestine, which is a place with very low levels of oxygen.

“More than half of the human body consists of microbes that do not tolerate oxygen very well,” professor of medical microbiology and immunology Andreas Bäumler explains in a university release.

Keeping gut bacteria away from the colon’s surface

The study finds the gut microbiota, the body’s community of microbes, stay away from the surface of the colon. This is important for avoiding inflammation triggered by accidental immune responses to healthy bacteria.

Until now, scientists believed the body kept these two apart using oxygen released from the cells. The discovery of this enzyme, NOX1, is rewriting what researchers know about how the gut works.

“We looked at the spatial relationships between the bacteria in the gut and its host, the colon,” Bäumler says. “We found that cells in the colon’s lining release hydrogen peroxide – not oxygen – to limit microbial growth.”

It turns out NOX1 produces a large amount of hydrogen peroxide inside the colon. The natural H2O2 helps to filter the microbes in the colon. Pathogens which use hydrogen peroxide can only do this if they attach themselves to the lining of the intestines. The results suggest the human body uses this disinfectant to protect the mucous membrane which covers the internal organs. This keeps gut bacteria from mixing with regions of the body it shouldn’t and keeps the inflammation that would cause away.

New direction in curing inflammation

Researchers say when the human body has a bacterial imbalance, it suffers from dysbiosis. This is a gastrointestinal condition which causes gut inflammation and symptoms like nausea and bloating to occur.

Typically, doctors treat dysbiosis with antibiotics. The new report suggests that physicians start taking a different approach to restoring gut health; one that focusing on fixing the function of microbes instead of wiping them out.

“We need to shift the focus of gut inflammation treatments from targeting bacteria to fixing habitat filters of the host and restoring their functionality,” Bäumler concludes.

The study appears in the journal Cell Host & Microbe.

About Chris Melore

Chris Melore has been a writer, researcher, editor, and producer in the New York-area since 2006. He won a local Emmy award for his work in sports television in 2011.

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