H&E staining (Fig. 5L), the inflammation scores, Masson staining, fiber score (Fig. 5M), PAS staining, and PAS score (Fig. 5N) showed less inflammatory infiltration, tracheal stenosis, fibrosis, and mucus formation in Spp1−/−+OVA+FMT group mice compared with Spp1−/−+OVA mice. Here, SPP1 is linked to stricture.