Association between Dietary Intake of Live Microbes and Asthma Risk in Children and Adolescents Aged 6-15 Years: A Cross-sectional analysis

Aim Emerging evidence implicates gut dysbiosis in asthma pathogenesis via the gut-lung axis. This cross-sectional study aimed to examine the associations between dietary live microbes intake and asthma risk among US children and adolescents aged 6 to 15 years.Methods We analyzed data from the 2007-2018 National Health and Nutrition Examination Survey. Dietary live microbes intake was evaluated using the Sanders method and categorized into low, medium, and high categories. Asthma status was determined by self-report. Multivariable binary logistic regression was used to evaluate the association between dietary live microbe intake and asthma prevalence.Results Of the 7,547 participants (mean age 10.8 years; 51.9% male) included, the overall prevalence of asthma was 11.3%. Compared with the low dietary live microbes intake group, the multivariate-adjusted odds ratio (95% confidence intervals) for asthma in the medium and high intake groups were 0.75 (0.63-0.88) and 0.52 (0.41-0.64), respectively (P for trend < 0.001). Subgroup analyses suggested trends toward stronger protective associations among girls (P for interaction = 0.073) and those exposed to household smoking (P for interaction = 0.070). Sensitivity analyses using propensity score matching and additional adjustment for prebiotics, probiotics, and synbiotics yielded results consistent with the primary analysis.Conclusions Higher dietary live microbe intake was significantly associated with lower asthma prevalence in US children and adolescents aged 6-15 years. These findings support additional investigation of dietary live microbe consumption as a modifiable factor for asthma prevention in this age group.