Clostridium leptum Attenuates Allergic Airway Inflammation via tDC‒Treg Axis Activation in a Murine Model of Gut Dysbiosis-Associated Asthma

To investigate whether oral CL administration restores gut–lung immune homeostasis and suppresses allergic inflammation via tDC/Treg induction in a dysbiosis-asthma comorbidity model, adult BALB/c mice were subjected to ovalbumin (OVA) sensitization/challenge and antibiotic-induced gut dysbiosis. The gut microbiota (16S rRNA sequencing), metabolome (untargeted LC‒MS), and immune parameters were assessed via histopathology, flow cytometry (tDCs: CD11c+CD80-CD86-; Tregs: CD4+CD25+FoxP3+), cytokine profiling (ELISA), and analyses of the TLR/NF-κB pathway (IHC/qPCR/WB).