What We Know about the Microbiome

by Jennifer L.W. Fink •

The gut microbiome may play a role in airway health

Scientists have noted links between gut microbiome composition and digestion, weight, and digestive diseases such as irritable bowel syndrome, and proven that manipulating the gut microbiome via fecal transplants is a highly effective treatment for recurrent Clostridium difficile infection. (Gastroenterol Hepatol (N Y). 2012;8:191–194; Infect Dis Clin North Am. 2015;29:109–122.)

Evidence also suggests that the gut microbiome may play a role in the health and function of the heart, brain, and airways. “We don’t know yet how much the gut microbiome matters for chronic rhinosinusitis or airway inflammatory diseases,” Dr. Ramakrishnan said. “One possibility is that the gut, which houses the vast majority of the microbes on our insides, could be a spot where systemic immune priming occurs. This adds another wrinkle to the whole question of, should we be looking at the sinuses, the gut, or both?”

Microbiome-Based Treatments Won’t Be Available Soon

Despite widespread desire for more effective treatments for sinus and airway disease, researchers say it will likely be years before microbiome research leads to new clinical treatments.

“I absolutely expect it will be three to five, or even more, years into the future,” Dr. Cope said. “There’s a lot of potential here; I don’t think we’ve really cracked it yet. But we’re still working on addressing core questions like, how do these altered microbial communities interact with the host system in the sinuses?”

Additional research is needed to determine why (and how) microbial disturbances occur, and to uncover the mechanisms by which changes in the microbiome might trigger inflammation and disease. “I think these mechanisms are really going to be the key to finding targeted interventions,” Dr. Chang said. Research may also teach clinicians how to safely tweak the sinus, oral, and upper and lower airway microbiomes.

“The microbiome isn’t a magic bullet; we can’t simply alter it in one manner and then everyone’s disease-free,” Dr. Cope said. “There’s a lot of basic research that’s still needs to be done to understand how to alter microbiota properly for specific groups of patients, and if doing so will help at all.”

Jennifer Fink is a freelance medical writer based in Wisconsin.

Take-Home Points

  • Dysbiosis is associated with chronic rhinosinusitis.
  • Particular strains of bacteria are more likely to be found in the microbiome of patients with diseased sinuses.
  • Topical antibiotics may alter the sinus microbiome.
  • Microbiome-based treatments won’t be available anytime soon.

Topical Antibiotics Can Alter the Sinus Microbiome

A variety of factors can influence the composition of the microbiome, including diet, lifestyle, early microbial exposures, pet ownership, and exposure to tobacco smoke. Additionally, twin studies suggest that microbiome determinants may be heritable.