Chronic sinusitis (also known as chronic rhinosinusitis, or CRS) is one of the most common human diseases, affecting 1 in 7 American adults. And like many other modern, chronic conditions, its prevalence appears to be increasing.
CRS is a debilitating and often intractable disease. Over 20 percent of patients are unresponsive to drug therapy, and up to 40 percent of patients do not respond to surgery.
The conventional viewpoint is that CRS is caused by the presence of certain harmful species of bacteria, such as Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. (1) In other cases, CRS may result from an immunologic reaction to fungi that colonize the sinuses. (2) Fungal species associated with this syndrome include Bipolaris specifera and Aspergillus, Curvularia, and Fusarium.
However, in a recent paper out of the University of California, San Francisco, Dr. Susan Lynch demonstrated that the primary difference between patients with CRS and control subjects was not the presence of any particular pathogenic species (which both groups had in similar amounts), but the overall diversity of the sinus microbiome. (3)
This discovery has important implications for how we can successfully treat CRS, and I will come back to it later in the article. But first, let’s take a step back and discuss the sinus microbiome—since this may be the first time you’ve heard about it.
The Microbiome: It’s Not Just about the Gut!
If you’ve been following this blog, listening to my podcast, or have read my book, you’ll know that the gut microbiome is one of my favorite topics.
But I’m not alone. Even mainstream media outlets like The New York Times, Time, The Wall Street Journal, and FOX News have done major stories on the gut microbiome and its importance in health and disease. It’s no longer an exotic concept that only scientists and health care professionals discuss; it’s now a household term.
Could probiotics be the answer to chronic sinusitis and nasal congestion?
Yet while it’s true that the majority of microbes that comprise our microbiome live in the gut, it’s also true that we have microbes in other areas of our bodies that play similarly important roles in maintaining health and preventing disease. These areas include the skin, vagina, penis, mouth, respiratory tract, and—you guessed it—the sinus cavity.
Prior to the development of DNA/PCR technology, our ability to determine the composition of microorganisms in these various areas was extremely limited. But thanks to recent advances in technology, we now have a much better idea of what “normal” and “abnormal” microbiomes look like—not only in the gut, but also on the skin and the penis and in the mouth, respiratory tract, and sinuses.
This understanding has profound implications for how we view the pathogenesis of diseases like CRS, and in turn, what treatment options might be available to patients in the future.
It’s the Forest That’s Important, Not the Trees
As I was reading Dr. Lynch’s seminal paper, I came across the following quote, which summarizes the importance of these recent discoveries and how they will change our approach to treating conditions that are microbial in their origin:
Because of extensive use of conventional laboratory culture approaches to detect microbial species, we have been conditioned to view chronic or acute infections as exclusively due to a single pathogenic species. However, recent studies have demonstrated that the composition of the resident microbiota in a given niche can strongly influence the behavior of specific species, particularly pathogens, and, as such, represents an important contributory factor to disease etiology.
The idea here is that it isn’t the presence of a particular pathogen that matters most, but rather the environment in which the pathogen is present. If you extend this idea to thinking about treatment approaches, it follows that focusing on eradicating a particular pathogen or species may be misguided, and that a better approach is restoring microbial diversity.
This has already become evident with the gut microbiome. Clostridium difficile is a virulent infection that still kills almost 30,000 people in the U.S. each year. We’ve thrown every antibiotic we have at it, but they are often ineffective in the most severe cases.
If we apply this same reasoning to the treatment of CRS, it suggests that probiotics—rather than antibiotics—may be a better solution. Antibiotics may kill harmful species of bacteria, but they are likely to further reduce microbial diversity, which would be expected to worsen CRS over time if Dr. Lynch’s theory is correct.
With this in mind, let’s see what the research has to say about probiotics and sinus problems.
Probiotics for Chronic Sinus Problems
As it turns out, there are several published studies suggesting that probiotics may be an effective treatment for chronic sinus problems.
One review in the Journal of Allergy found that “an emerging number of publications demonstrate beneficial effects using probiotics in clinical double-blind placebo-controlled trials in allergic rhinitis (AR).” (5) Although data on probiotics and non-allergic CRS are lacking, there are several lines of evidence to suggest that probiotics may be effective in these cases.
First, probiotics have been shown to disrupt biofilms, which are present in CRS and difficult to eradicate through other means. (6)
Second, both human and animal studies have shown that oral probiotics reduce colonization of the nose and upper respiratory tract by pathogenic bacteria (e.g., Staphylococcus aureus, Streptococcus pneumoniae, and β-hemolytic streptococci). (7, 8)
Third, upper respiratory tract infections often precede the development of CRS, and probiotics have been shown to be effective in preventing them. (9)
Finally, although this is certainly not peer-reviewed evidence, I can tell you anecdotally from my work with patients that many CRS sufferers do seem to improve with strategies aimed at restoring the microbiome—such as eating more fermentable fiber and fermented foods, and/or taking prebiotics and probiotics.
Future Directions: Nasal Probiotic Sprays for Repopulating the Sinus Microbiome?
Dr. Lynch found that most patients with CRS are lacking in a particular species of bacteria called Lactobacillus sakei. This bacteria is a natural, protective species in our nose, but (as the name implies) it is also used to make certain fermented beverages and foods like sake and kimchi.
One might suspect that Dr. Lynch and her peers are developing a nasal spray that contains Lactobacillus sakei to be used in the treatment of CRS. Of course such a treatment will have to be developed and tested for safety and effectiveness in human clinical trials.
Given that this may take several years, some folks have decided to take matters into their own hands, er, noses.
A blog called Lacto Bacto, which is written by CRS sufferer Mara Silgailis, describes a DIY approach that appears to have helped many people with CRS. It involves putting small amounts of kimchi juice directly into the nostrils. According to Mara, she has essentially cured herself and her family of their long-term CRS, and they have been antibiotic-free for more than two years.
Along the same lines, I’ve heard anecdotal reports from patients and people online who have created DIY nasal probiotic sprays and even crushed up probiotic tablets and sniffed them, achieving somewhat miraculous results.
Of course I can’t recommend or endorse these procedures, because they haven’t been tested for safety or efficacy. It would seem that the risk is relatively low, but it’s at least possible that some of the other microbes in kimchi or other oral probiotics may not be beneficial for the sinus microbiome. We’re really just starting to scratch the surface in this area of research, and there’s still a lot that we don’t understand. So if you decide to perform these experiments at home, proceed at your own risk!