Probiotics for Otolaryngologic Disorders

The role of the microbiome in allergic dermatitis-related otitis externa: a multi-species comparative review

The external ear canal, characterized by species-specific structural and physiological differences, maintains a hostile environment that prevents microbial overgrowth and foreign body entry, supported by factors such as temperature, pH, humidity, and cerumen with antimicrobial properties. This review combines several studies on the healthy ear canal's structure and physiology with a critical approach to the potential existence of an ear microbiome. We use a comparative multi-species approach to explore how allergic conditions alter the ear canal microenvironment and cerumen in different mammalian species, promoting pathogen colonization. We propose a pathogenetic model in which allergic conditions disrupt the antimicrobial environment of the EEC, creating circumstances favorable for facultative pathogenic micro-organisms like Staphylococcus and Malassezia species, leading to otitis externa (OE). A better understanding of the underpinning mechanisms may lead to innovative approaches to disease mitigation.

Association Between Dietary Factors and Chronic Sinusitis Among Korean Individuals: Insights From a Large Population-Based Study in Asia

Objective: Population-based studies on chronic sinusitis have predominantly focused on Europe and the Americas, but research on chronic sinusitis within large Asian populations remains scarce. This study aims to explore the link between dietary factors and chronic sinusitis among ethnic Koreans in Asia. Design: A cross-sectional study. Setting: Data were collected from the Korean National Health and Nutrition Examination Survey (KNHANES) in 2012. Participants: Participants in the study were included based on a doctor's diagnosis of chronic sinusitis, as determined through the ear, nose, and throat examination questionnaires. Results: Adolescents [adjusted P value (aP) < .001, adjusted odds ratio (aOR) = 1.881, 95% confidence interval (CI) = 1.380-2.564] and individuals with college and higher education (aP = .042, aOR = 1.298, 95% CI = 1.009-1.669) were more likely to develop chronic rhinosinusitis. In addition, levels of dietary fat [P = .001, interquartile range (IQR) = 34.085] and energy intake (P = .004, IQR = 981.106) were associated with an increased risk of chronic sinusitis. Moreover, high dietary inflammatory index (aP < .001, aOR = 0.547, 95% CI = 0.415-0.721), and high intake of fried pork chops (aP = .028, aOR = 1.335, 95% CI = 1.033-1.777), bread (aP = .024, aOR = 1.364, 95% CI = 1.042-1.786), and rice (aP = .021, aOR = 1.382, 95% CI = 1.051-1.818) were risk factors for chronic sinusitis, while cucumber consumption (aP < .001, aOR = 0.547, 95% CI = 0.415-0.721) was a protective factor for chronic sinusitis. Conclusion: This study revealed a significant correlation between diet and development of chronic sinusitis. These findings suggest that promoting an anti-inflammatory dietary pattern and providing guidance on healthy eating habits could help reduce the incidence of chronic sinusitis and enhance its management.

STAT4 Phosphorylation of T-helper Cells predicts surgical outcomes in Refractory Chronic Rhinosinusitis

Objective

Chronic rhinosinusitis (CRS) impacts an estimated 5% to 15% of people worldwide, incurring significant economic healthcare burden. There is a urgent need for the discovery of predictive biomarkers to improve treatment strategies and outcomes for CRS patients.

Study design

Cohort study of CRS patients and healthy controls using blood samples.

Setting

Out-patient clinics.

Methods

Whole blood samples were collected for flow cytometric analysis. Mechanistic studies involved the transfection of human primary T cells and Jurkat cells.

Results

Our analysis began with a 63-69 year-old female patient diagnosed with refractory CRS,. Despite undergoing multiple surgeries, she continually faced sinus infections. Whole exome sequencing pinpointed a heterozygous IL-12Rb1 mutation situated in the linker region adjacent to the cytokine binding domain. When subjected to IL-12 stimulation, the patient's CD4 T-cells exhibited diminished STAT4 phosphorylation. However, computer modeling or T-cell lines harboring the same IL-12 receptor mutation did not corroborate the hypothesis that IL-12Rb could be responsible for the reduced phosphorylation of STAT4 by IL-12 stimulation. Upon expanding our investigation to a broader CRS patient group using the pSTAT4 assay, we discerned a subset of refractory CRS patients with abnormally low STAT4 phosphorylation. The deficiency showed improvement both in-vitro and in-vivo after exposure to Latilactobacillus sakei (aka Lactobacillus sakei), an effect at least partially dependent on IL-12.

Conclusion

In refractory CRS patients, an identified STAT4 defect correlates with poor clinical outcomes after sinus surgery, which can be therapeutically targeted by Latilactobacillus sakei treatment. Prospective double-blind placebo-controlled trials are needed to validate our findings.

Modulation of Gut Microbiome as a Therapeutic Modality for Auditory Disorders

The gut microbiome has been shown to play a pivotal role in health and disease. Recently, there has been increased interest within the auditory community to explore the role of the gut microbiome in the auditory system and its implications for hearing disorders such as sensorineural hearing loss (SNHL), otitis media, and tinnitus. Studies have suggested that modulating the gut microbiome using probiotics as well as with diets high in monounsaturated and omega-3 fatty acids is associated with a reduction in inflammation prevalence in auditory disorders. This review aims to evaluate the current literature on modulation of the gut microbiome and its effects on otological conditions. The probiotic conversion of nondigestible carbohydrates into short-chain fatty acids has been shown to provide benefits for improving hearing by maintaining an adequate vascular supply. For acute and secretory otitis media, studies have shown that a combination therapy of probiotics with a decreased dose of antibiotics yields better clinical outcomes than aggressive antibiotic treatment alone. Gut microbiome modulation also alters neurotransmitter levels and reduces neuroinflammation, which may provide benefits for tinnitus by preventing increased neuronal activity. Further studies are warranted to evaluate the efficacy of probiotics, natural health products, and micronutrients on auditory disorders, paving the way to develop novel interventions.