Propionate attenuates spontaneous AD-like dermatitis in sebum-deficient mice. (A) Gross appearance of skin lesions in Cidea KO and WT mice. The line down the middle of this panel is used to divide the two types of mice. (B–E) TEWL (B), epidermal hydration (C), total serum IgE (D), and scratching frequency (E) in Cidea KO and WT mice (n = 8 per group). (F) SCFA levels on the skin surface of Cidea KO and WT mice (n = 6 per group). (G) Gross appearance of skin lesions in Cidea KO mice before and after topical propionate treatment. The red box indicates the skin lesions treated with propionate. (H) The severity scores of skin lesions in Cidea KO mice before and after propionate treatment (n = 4). (I) H&E staining of skin samples from WT mice, lesional skin of Cidea KO mice, and lesional skin of Cidea KO mice treated with propionate. (J) Western blotting showing the protein expression of IL-33 in skin samples of WT mice, lesional skin of Cidea KO mice, and lesional skin of Cidea KO mice treated with propionate (Prop). Scale bar = 1 cm (A and G); 100 μm (I). Data are representative of three independent experiments and are expressed as means ± SEM. Statistical significance was analyzed by unpaired t test with Welch’s correction (B–F) and paired t test (H). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. Source data are available for this figure: SourceData F6.