Abstract
BACKGROUND: Allergic rhinitis (AR) is a prevalent immune-mediated disease, increasingly affecting children and adolescents. While diet is suspected to influence allergic diseases, the link between polyunsaturated fatty acids [PUFAs; omega-3 (n-3), and omega-6 (n-6)] and AR, particularly in younger populations, remains unclear. The gut microbiota's role as a potential modifier also warrants investigation. This study aims to assess the correlation between dietary PUFA intake and AR status and explore the potential involvement of gut microbiota characteristics. METHODS: This cross-sectional study analyzed data from the 2007-2016 National Health and Nutrition Examination Survey (NHANES), including 994 children and adolescents (1-16 years). Dietary PUFA intake [total PUFAs (TPFAs), n-3, and n-6] was assessed using 2-day 24-hour dietary recalls. AR status was determined by self-reported physician diagnosis and symptoms in the past year. Covariates, including demographics, clinical conditions, and dietary components, were adjusted for. Gut microbiota data were obtained from an external cohort involving 16S ribosomal RNA (rRNA) sequencing of fecal samples from 24 AR patients and 25 healthy controls, focusing on the V3-V4 region. Generalized linear mixed-effects models were used to evaluate associations between PUFA intake and AR, accounting for random effects and key interactions. RESULTS: The study included 994 participants (mean age 9 years; 46.4% male). TPFA intake was significantly associated with an increased risk of AR [odds ratio (OR) =1.02; 95% confidence interval (CI): 1.00-1.04; P=0.03]. Specifically, n-6 PUFA intake was positively associated with AR risk (OR =1.02; 95% CI: 1.00-1.04; P=0.03), with octadecadienoic acid/18:2 (OR =1.02; 95% CI: 1.01-1.03; P=0.03) and octadecatrienoic acid (OR =1.23; 95% CI: 1.02-1.49; P=0.03) showing significant effects. No significant association was found between total n-3 intake and AR. The gut microbiome in AR patients showed a higher Firmicutes/Bacteroidetes (F/B) ratio and altered abundance of specific bacteria compared to healthy controls. CONCLUSIONS: Higher n-6 PUFA intake is associated with an increased risk of AR in children and adolescents and may contribute to gut microbiota dysbiosis, characterized by an elevated F/B ratio and reduced abundance of beneficial short-chain fatty acid (SCFA)-producing bacteria. N-3 PUFAs may help alleviate AR symptoms by modulating gut microbial composition and promoting anti-inflammatory responses. Dietary interventions optimizing the n-6/n-3 PUFA ratio and strategies to restore gut microbiota balance could offer potential avenues for AR prevention and management. Further research is needed to clarify causal relationships and underlying mechanisms involving PUFA intake, gut microbiota, and immune regulation in AR.