In case you hadn’t heard, your body is host to several trillion foreigners, bacteria mostly. There far more bacterial cells in your body than your own cells, but to keep it in perspective, they amount to about 200 grams (7.1 ounces) of your total weight. Still, they are significant.
In the last ten years or so there has been an explosion of research and findings, particularly about the bacteria living in the digestive system – a microbiome – or bacterial environment that plays an essential role in digestion and most likely many other aspects of a person’s health.
Now comes a new study from researchers at the University of California San Francisco, published in Science Transactional Medicine that describes another microbiome, this time in the nose and sinuses.
It’s fair to say that almost everyone alive has at one time or another suffered from sinusitis, a chronic inflammation of the lining of the sinuses. It is, in fact, one of the most common reasons for visits to the doctor’s office in the United States. There are about 30 million cases a year. So we all know about sinuses, mostly from unpleasant experience.
There are four pairs of paranasal sinuses arranged symmetrically around the nose. They’re hollowed-out areas within bones and connected to the airflow of the nose through narrow channels called ostia.
The ostia often cause problems. When you have a common cold, the ostia frequently plug with mucus, trapping material in the sinuses. That’s when the sinuses become infected and the inflammation of sinusitis begins.
Medically, the sinuses are something of a puzzle. After all the years and multiple studies, medical science still doesn’t know for sure what the sinuses are supposed to do.
They’re obviously not like the appendix, with mainly a vestigial purpose, but their biological role in most mammals and birds is up for debate. Some of the functions proposed are:
- Reducing the weight of head bones (This may apply to birds, but mammals?)
- Increasing the resonance of the voice or call
- Humidifying and heating of inhaled air
- insulating sensitive organs such as teeth roots and eyes from rapid temperature change in the nose
- Sensing toxic and bacterial presence for the immune system
The new study leans heavily in the direction of the last function – the sinuses playing a role in the immune system. According to the researchers, the sinuses normally contain a diverse community of bacteria, a microbiome, in much the same way as the digestive tract. They believe this community of bacteria very likely is part of the immune system, acting as a testing area for airborne bacteria and toxins.
By comparing the sinus bacteria of ten healthy people with the bacteria found in ten people with sinusitis, they discovered that a particular bacterium, Corynebacterium tuberculostearicum is the likely culprit. Its population increases radically in infected sinuses.
At the same time, a number of other ‘normal’ bacteria in the sinuses decrease, in particular, Lactobacillus sakei, which appears to be a bacterial agent of the immune system that fights off attacks on the sinuses. The research suggests that restoring this natural bacterium may be a way of treating sinusitis.
Traditionally for sinusitis, doctors prescribe antihistamines to reduce the inflammatory swelling and decongestants to clear some of the mucus. If the sinusitis is severe, they may also prescribe corticosteroids or antibiotics. The new research may show that especially, antibiotics may be inappropriate.
As Andrew Goldberg MD, co-author of the study and director of Rhinology and Sinus Surgery at UCSF puts it, “…the premise for our understanding of chronic sinusitis and therapeutic treatment appears to be wrong, and a different therapeutic strategy seems appropriate.” In short, it’s time to look for a different approach to treating sinusitis, approaches that involve restoring the natural microbiome rather than blasting bad bacteria or resorting to surgery.
His suggestion echoes many similar suggestions made for the microbiome of the digestive system. Doctors and medical researchers are gradually learning that many of the previous approaches – especially powerful antibiotics – are more harmful to the microbiome than curative.
The insight provided by this study will lead to research in new treatment for sinusitis. In fact, some of the principles in the study have already filed a patent application for sinusitis diagnostics and treatment.
However, it will be years before the results of their research become generally available. As they say, there are many avenues of approach to restoring a normal sinus microbiome. There will be a long process of clinical trials to determine which of the approaches is safe and effective.
sinusitis, sinuses, microbiome, nasal microbiome, digestive microbiome, bacteria, lactobacillus sakei, antibiotics