Common skin bacteria may be linked to chronic sinusitis

A common bacteria ever-present on the human skin and previously considered harmless, may, in fact, be the culprit behind chronic sinusitis, according to a study by scientists at the University of California, San Francisco.

Sinusitis is a painful, recurring swelling of the sinuses that strikes more than one in ten Americans each year. The study, published in the journal Science Translational Medicine, links the condition with an opportunistic bacteria that sets in following an infection.

In their study, the researchers compared the microbial communities in samples from the sinuses of 10 patients with sinusitis and from 10 healthy people, and showed that the sinusitis patients lacked a slew of bacteria that were present in the healthy individuals. The patients also had large increases in the amount of the opportunistic  bacteria, Corynebacterium tuberculostearicum in their sinuses, which are located in the forehead, cheeks and eyes.

The team also identified a common bacterium found within the sinuses of healthy people called Lactobacillus sakei that seems to help the body naturally ward off sinusitis. In laboratory experiments, inoculating mice with this one bacterium defended them against the condition.

“Presumably these are sinus-protective species,” said Susan Lynch, PhD, an associate professor of medicine and director of the Colitis and Crohn’s Disease Microbiome Research Core at UCSF.

What it all suggests, she added, is that the sinuses are home to a diverse “microbiome” that includes protective bacteria. These “microbial shields” are lost during chronic sinusitis, she said, and restoring the natural microbial ecology may be a way of mitigating this common condition.

There are about 30 million cases of sinusitis each year in the U.S., that costs the healthcare system an estimated $2.4 billion dollars.