Frequent intake of high fiber and probiotic diets lowers risks associated with atopic dermatitis and house dust mite allergy: a cross-sequential study of young Chinese adults from Singapore and Malaysia

Purpose: Dietary fiber intake may influence the risk and severity of atopic dermatitis (AD), a common chronic allergic skin condition. This cross-sequential study investigated the association between dietary fiber intake and various characteristics of AD, including house dust mites (HDM) allergy and dry skin, in 13,561 young Chinese adults (mean years = 22.51, SD ± 5.90) from Singapore and Malaysia. Methods: Dietary habits were assessed using a validated semi-quantitative, investigator-administered food frequency questionnaire from the International Study of Asthma and Allergies in Childhood. We derived an amount-based dietary index to estimate fiber intake while studying its correlation with probiotic drinks intake. AD status was determined by skin prick tests for HDM and symptomatic histories of eczema. Multivariable logistic regression analysis, adjusting for demographic, genetic predisposition, body mass index and lifestyle factors, and synergy factor analysis were used to explore the association and interaction of dietary factors on disease outcomes. Results: High fiber intake (approximately 98.25 g/serving/week) significantly lowered the associated risks for HDM allergy (Adjusted Odds Ratio [AOR]: 0.895; 95% Confidence Intervals [CI]: 0.810–0.989; adjusted p-value < 0.05) and AD (AOR: 0.831; 95% CI: 0.717–0.963; adjusted p-value < 0.05), but not dry skin. While probiotic intake was not associated with AD, it was significantly correlated with fiber intake (R2 = 0.324, p-value < 0.0001). Among those frequently consuming probiotics, moderate fiber intake sufficiently lowered the AD risk (AOR: 0.717; 95% CI: 0.584–0.881; adjusted p-value < 0.01). Moreover, a fibre-rich diet independently mitigated risks associated with high intake of fats, saturated fats, and protein. Conclusion: A high-fiber diet is associated with AD and HDM allergy. Moderate-to-high fiber intake, particularly in conjunction with probiotics, may further mitigate AD risks. © The Author(s) 2024.