Human noses play host to beneficial bacteria, experts consider using them to make probiotics
After the human gut, it is time for the nose to shine. Within the nasal region, researchers have discovered a treasure trove of beneficial bacteria. And they appear to promise good health.
In a new study, researches from Belgium have found that noses of healthy adults play host to 30 different families of bacteria. These microorganisms may guard against allergies and chronic rhinosinusitis – a condition that causes pain and swelling in the sinuses and nasal cavity, the researchers said. The latter, which reduces the quality of life, affects 1% to 5% of the US and more than 11% in Europe.
The study opens doors to recognizing the protective qualities of bacteria in a new part of the body, Maria Marco, a microbiologist at the University of California, Davis, who was not involved with the work, told Science. “There’s been some work done in the past, but this is the first study that goes in-depth," she added.
Bringing the research on the underexplored region to the spotlight was a researcher's personal experience. Microbiologist Sarah Lebeer, from the University of Antwerp in Belgium and senior author of the study, recalled how her mother had to undergo a surgery for lifelong problems with headaches and chronic rhinosinusitis. "My mother had tried many different treatments, but none worked," she said in a statement. "I was thinking it's a pity that I could not advise her some good bacteria or probiotics for the nose. No one had ever really studied it."
So Lebeer and her colleagues enrolled 100 healthy adults and 225 people with chronic rhinosinusitis with one goal: to study 30 different families of bacteria occupying the nose. Among them, Lactobacilli caught the eye of the researchers. The microbe is commonly found in the human gut and genital regions, and also in fermented food such as cheese or yogurt.
Healthy adults had 10 times more Lactobacilli than the other group. But something did not quite add up -- this bacteria is best suited to live in places with low oxygen levels, but the nasal region is oxygen-rich. Further analysis showed that Lactobacilli had adapted itself to live in a high-oxygen environment. Helping them colonize human noses are hair-like appendages called fimbriae. It also helps them attach to the organ's inner surface. What is more, these organisms can inhibit the growth and incapacitate harmful pathogens.
At the moment, the beneficial qualities of Lactobacilli are mere speculations. To confirm if the theory holds weight, Lebeer and her team will have to experiment on animals. But even this is challenging. "The microbiome of the nose of mice compared with humans, it's certainly different. Also, mice are nose breathers and they don't get chronic rhinosinusitis; they have fewer allergies and inflammations," Lebeer explained.
The team now hopes to make probiotics containing Lactobacilli. "We think that certain patients would benefit from remodeling their microbiome and introducing beneficial bacteria in their nose to reduce certain symptoms," Lebeer said. "But we still have a long way to go with clinical and further mechanistic studies," she added.
The study appears in Cell Reports.