Bifidobacterium-driven immunoglobulin A production in pediatric patients with IgA deficiency and recurrent respiratory tract infections (microbiomejournal.biomedcentral.com)

• 38% of children with rRTIs had IgA deficiency; gut microbiota composition differed significantly.
• Fecal transplantation into germ-free mice induced IgA production in stool, serum, and lung.
• Bifidobacterium cluster linked to higher IgA levels and reduced infection severity.

"A study of children with recurrent respiratory infections and IgA deficiency found altered gut microbiota. Fecal transfer to germ-free mice induced IgA production; a Bifidobacterium cluster was associated with higher IgA in stool, serum, and lung. Higher Bifidobacterium abundance correlated with milder respiratory symptoms in children."