Figure 5.

Clostridia butyricum provides systemic butyrate to dampen ILC2 dependent AHR. Germ-free RAG^−/− mice gavaged with 1 × 10⁶ pfu Clostridia butyricum and Clostridia Sporogenes (butyrate producer, BUT+) or two strains of Clostridia ramosum (non-butyrate producer, BUT–) every other day over 5 days, followed by once daily 0.5 ug rmIL-33 challenge intranasal for 3 days. Twenty four hours after last challenge, Lung function and composition was analyzed. (A) Schematic. (B) SCFA levels in Lung homogenate measured by LC-MS. (C) Representative flow plots, percentage and number of IL-5 and IL-13 producing ILC2 in BAL after PMA ionomycin/BFA. (D) Representative flow plots, percentage and number of IL-17a producing ILC2 as in (C). (E) Total Eosinophils in BAL. (F) Total Neutrophil count in BAL. (G) Lung resistance (AHR) upon methacholine challenge. Data representative of two independent experiment, n = 8 mice/group+-SEM. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001, and ^****p < 0.0001.