September 13, 2012
Chronic Sinusitis May Be Linked To Common Bacteria
Lawrence LeBlond for redOrbit.com - Your Universe Online
The human body is riddled with bacteria, some of which can be harmful under the right set of circumstances, while others are completely harmless. One particular bacterium, Corynebacterium tuberculostearicum, which has been long-presumed harmless, may actually be the culprit behind chronic sinusitis, a painful, recurring swelling of the sinuses that affect 10 percent of Americans every year.Evidence of this startling new discovery comes from a team of scientists from the University of California, San Francisco. Reporting the findings in the journal Science Translational Medicine, the researchers explain that sinusitis may be linked to the loss of normal microbial diversity within the sinuses following an infection and the subsequent colonization of the C. tuberculostearicum bacterium.
The team compared the microbial communities in samples from the sinuses of ten patients with sinusitis and from ten healthy people. The results of this comparison showed that those with sinusitis lacked a treasure trove of bacteria that were present in the sinuses of the healthy group. The sinusitis group also had a large increase in the amount of the C. t. bacterium in their sinuses.
The team also identified a common bacterium, Lactobacillus sakei, found within the sinuses of healthy people that seems to help the body ward off sinusitis. The team replicated the results in lab experiments with mice, inoculating them with the sinusitis-fighting bacterium.
“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. She said that the sinuses are usually home to a diverse “Microbiome” that includes protective bacteria. But when sinusitis strikes, the protective bacteria are absent. She suggested that restoring these natural protectors may be a way of alleviating this common condition.
The prominent role of the sinuses remain unclear to scientists, with some suggesting they exist to heat air as it passes into the body, and others saying they may be associated with the immune system. Lynch and her colleagues speculate that they may represent a site of microbial surveillance, inspecting bacteria and other particles as they enter the airways.
Whatever their role, they sure are an all too familiar nightmare for patients who are suffering and for doctors who are trying to treat the condition. Sinusitis is one of the most common reasons why people go to the doctor in the US. An estimated 30 million cases of sinusitis occur each year, and the cost of treating the painful condition reaches nearly $2.5 billion annually.
While the researchers are hopeful that this new discovery may one day lead to an effective way to treat sinusitis, they said the findings are still preliminary and further studies are needed. They also caution that any new approaches based on these observations still have to be developed and tested for safety and effectiveness in human clinical trials.
This study was supported by the American Rhinological Society, the Rainin Foundation, the National Institute of Allergy and Infectious Diseases (NIAID), the Minority Biomedical Research Support-Research Initiative for Scientific Enhancement, the California Institute for Regenerative Medicine (CIRM), and the Rebecca Susan Buffett Foundation.