You may have considered the microbiome of your gut an important part of your immune system, but have you thought about the bacteria living in your nose as being beneficial or detrimental? With advances in laboratory technology and testing in recent years, the important role of microbiota in support of your immune system is becoming clearer.

Nasal Bacterial Reservoir
The recent pandemic, with the ongoing debate over the efficacy of wearing face, may be driving rising interest in the bacterial reservoir of your nose. Many types of viral or bacterial infections can enter through the nose, including the common cold, flu, SARS-CoV-2, and acute bacterial rhinosinusitis, which often starts as a viral infection.

Microbiota and Immunity
Viruses that enter the body through the nose, the mucosa becomes inflamed, creating an environment where bacteria can thrive and triggering an upper respiratory infection, which may result in a runny nose, fever, chills and coughing.

Research has shown that the microbiota in your nose change as you age and affects the functioning of your immune system. This implies there may be a role for probiotic supplementation to help support your nasal microbiota and therefore bolster your immune response to airborne pathogens.

Chronic Rhinosinusitis
The reported incidence of chronic rhinosinusitis fluctuates from 1%3 of the population to 11.5%, depending upon the severity of symptoms being measured.4 In one sample of 10,336 U.S. adults, data were collected using a questionnaire to determine symptoms of chronic rhinosinusitis, the impact of the symptoms on the individual’s life, how long they lasted and the treatment used.

The researchers found that 11.5% of those who responded reported symptoms and duration that met the criteria for chronic rhinosinusitis. Interestingly, about 10% of those with the condition also reported having a diagnosis of nasal polyps.

Typical symptoms include:

• Pain, tenderness and swelling around facial structures such as the eyes, nose and forehead
• Pain in the upper jaw or teeth
• Pain in the face that gets worse when you lean forward
• Reduced sense of smell and taste
• Cough or throat clearing
• Ear pressure
• Headache
• Bad breath
• Fatigue

Although the symptoms are similar, there are different types of sinusitis including acute, chronic, and recurrent. Acute sinusitis lasts up to four weeks and can go away with little if any, treatment. Recurrent sinusitis can happen four or more times in one year with periods of time without symptoms. With chronic sinusitis, the symptoms are there almost all the time.

Probiotics for Prevention and Treatment
Sarah Lebeer, a microbiologist and microbiome researcher at the University of Antwerp, became interested after her mother had surgery to treat headaches and chronic rhinosinusitis. Lebeer, who had been studying the use of probiotics for the gut and vagina to improve health, shifted her focus to probiotics to help treat chronic rhinosinusitis.

The study began by comparing the bacteria found in 100 healthy people to 225 people with chronic rhinosinusitis. They chose 30 different families of bacteria and discovered the healthy group of individuals had up to 10 times more lactobacilli in some parts of the nose than did those with chronic rhinosinusitis.

Lactobacilli are an important part of balanced gut microbiome – aka the class of bacteria advertised as the beneficial bacteria in yogurt, lactobacillus acidophilus. The group found the most abundant lactobacilli in the healthy group of individuals belonged to the Lactobacillus casei group, which had been given a new genus name: Lacticaseibacillus. After isolation and genome sequencing, they found that the bacteria appeared to be similar to available probiotics for oral consumption found in food. However, there were indications that they were distinctive and had developed adaptations to the upper respiratory tract.

Most lactobacilli prefer the relatively low oxygen environment in the gut, but this genus appeared to have adapted to higher oxygen levels, oxidative stress, high airflow in the nasal cavity – and had “flexible, hair-like tubes called fimbriae, which allow them to adhere to the surface cells in the nose, indicating an interaction between the bacteria and host.”

Summary
In their analysis they found Lactobacillus casei inhibited the growth of pathogens found in the nasal cavity, and the respiratory epithelium tolerated the bacteria as they produced fewer interleukin and tumor necrosis factors in comparison to the pathogens.

Reference: Article at Mercola.com – 10 August 2020