Bifidobacterium-driven Immunoglobulin A Production in Pediatric Patients with IgA Deficiency and Recurrent Respiratory Tract Infections

Immunoglobulin A (IgA) deficiency is the most common primary antibody deficiency and contributes to recurrent respiratory tract infections (rRTIs) in children, with prevalence rates in this group ranging from 1:4 to 1:65. Previous studies in healthy humans and animals suggest that the gut microbiota significantly influences IgA production. We investigated the role of the gut microbiota in IgA deficiency and its potential in promoting IgA induction in children with rRTIs. Children under 7 years of age with rRTIs were enrolled in a prospective cohort study. Serum and feces were collected for IgA level measurement using ELISA and to determine the composition of the intestinal microbiota by 16S rRNA sequencing. We included 82 children with rRTIs, 38