Gut microbiota dysbiosis and amino acid metabolic dysregulation in children with allergic rhinitis complicated by constipation.

UNLABELLED: This study investigates the pathogenesis of constipation in children with allergic rhinitis (AR) by analyzing gut microbiota (GM) composition and fecal metabolites. We enrolled 21 AR children (AR group) and 16 AR children with constipation (ARFC group), performing absolute quantitative 16S rRNA sequencing and non-targeted metabolomics on fecal samples. The key findings are as follows: (i) The ARFC group exhibited significantly elevated Hungatella abundance (P = 0.033) and reduced beneficial genera (Bifidobacterium, Blautia, etc.; P < 0.05). (ii) Fecal metabolomics revealed upregulation of indoxyl sulfate and downregulation of amino acid metabolites (e.g., aromatic and branched chain amino acids) in ARFC children, with enriched pathways in amino acid metabolism and nutrient absorption. (iii) Correlation analysis demonstrated a positive association between Hungatella and indoxyl sulfate, as well as between diminished probiotics and disrupted amino acid metabolism. These results suggest that Hungatella and indoxyl sulfate may serve as microbial and metabolic biomarkers for constipation in AR children. GM dysbiosis linked to amino acid dysregulation could drive constipation pathogenesis, highlighting potential therapeutic targets for probiotic or dietary interventions.

IMPORTANCE

Allergic rhinitis (AR) is a common allergic disorder in children, often accompanied by gastrointestinal symptoms such as constipation, yet the underlying mechanisms remain poorly understood. This study reveals that constipation in AR children is associated with specific gut microbiota alterations-particularly an increase in Hungatella and a decrease in beneficial genera like Bifidobacterium-and disrupted amino acid metabolism, notably elevated indoxyl sulfate. These findings provide novel microbial and metabolic biomarkers for constipation comorbidity in AR patients. By highlighting the role of gut microbiota dysbiosis and metabolic dysregulation in driving gastrointestinal dysfunction, this work underscores the potential for microbiota-targeted interventions, such as probiotics or dietary adjustments, to improve both gut health and allergic outcomes in children.

CLINICAL TRIALS: This study is registered with Chinese Clinical Trial Registry as ChiCTR2400085982.