Fig 1.
High-fiber diet ameliorates the disease severity of MOG-induced EAE.
(A) EAE was induced in B6 mice by immunization with MOG35–55. Mice were fed a high-fiber, low-fiber or control diet 2 weeks before immunization and throughout the study. *P<0.05, **P<0.005, low-fiber versus high-fiber group. †P<0.05, control versus high-fiber group. Data are expressed as the means ± SEM of 9–10 mice per group. (B) Histopathological assessment of the CNS in EAE-induced mice. Cellular infiltration of the spinal cord of mice on day 30 is shown. Paraffin-embedded spinal cords were stained with hematoxylin and eosin (H&E). Scale bar = 200 μm (upper panels) or 50 μm (lower panels). (C) HPLC quantification of SCFA levels in the cecal contents.
Fig 2.
Oral administration of SCFAs ameliorates the disease severity of MOG-induced EAE.
EAE was induced in B6 mice by immunization with MOG35–55. Mice were orally administrated with SCFAs. *P<0.05, control versus acetate group. †P<0.05, control versus propionate group. ‡P<0.05, control versus butyrate group. Data are expressed the means ± SEM of 5 mice per group. Representative data from two separate experiments are shown.
Fig 3.
T cell responses in mice orally administrated with SCFAs.
(A) B6 mice were administrated with SCFAs and then immunized with MOG35–55. Then, 10–11 days after immunization, draining lymph node cells were incubated with MOG35–55. Supernatants were collected from the culture and measured for the concentrations of IFN-γ and IL-17 by ELISA. Data represent the mean ± SEM of samples pooled from four similar experiments (n = 13 mice). *P<0.05, ** P< 0.01, control versus butyrate group. (B) The frequency of Tregs in spleen (SPN) and draining lymph node (LN) obtained from mice treated with SCFAs were measured using flow cytometry.*P<0.05, ** P< 0.005 versus control.
Fig 4.
Oral administration of SCFAs ameliorates the disease severity of CIA.
(A) Clinical scores of CIA in DBA1/J mice with orally administrated SCFAs 3 weeks before immunization with CII and throughout the study. The data shown are pooled from two similar experiments. Data are expressed as the means ± SEM of 10 mice per group. ** P<0.005, control versus butyrate group. (B) Representative histological features of joints in control and SCFAs-treated mice (H&E stained; original magnification ×40). Scale bar = 500 μm. (C) Quantification of histological assessment of joints 46–48 days after induction of CIA. Result shown is the mean + SEM of 5 mice per group. *P<0.05, ** P<0.005, versus control group.
Fig 5.
Effect of SCFAs on K/BxN mouse serum–induced arthritis.
(A) Clinical scores of K/BxN mouse serum–induced arthritis in B6 mice treated with orally administrated SCFAs 3 weeks before K/BxN mouse serum–induced arthritis induction and throughout the study. *P<0.05, **P<0.005, control versus acetate group. †P<0.05, control versus propionate group. Results shown are the mean + SEM of 10 mice per group. The data shown are pooled from two similar experiments. (B) Representative histological features of joints in control and SCFAs-treated mice. (H&E stained; original magnification ×40). Scale bar = 500 μm. (C) Quantification of histological assessment of joints 10 days after induction of K/BxN mouse serum–induced arthritis is shown in A. Results shown are the mean + SEM of 3 mice per group. *P<0.05 control versus acetate group.
Fig 6.
Effect of a high-fiber diet on K/BxN mouse serum–induced arthritis.
(A) Clinical scores of K/BxN mouse serum–induced arthritis in B6 mice fed a high-fiber, low-fiber, or control diet 2 weeks before the transfer of serum of K/BxN mouse and throughout the study. *P<0.05, **P<0.005, low-fiber versus high-fiber group. †P<0.05, ††P<0.005, control diet versus high-fiber group. Results shown are the mean + SEM of 10 mice per group. The data shown are pooled from two similar experiments. (B) Representative histological features of joints in control, low- or high-fiber diet mice (H&E stained; original magnification ×40). Scale bar = 500 μm. (C) Quantification of histological assessment of joints 10 days after induction of K/BxN mouse serum–induced arthritis is shown in A. Results shown are the mean + SEM of 3 mice per group. **P<0.005, low-fiber versus high-fiber group. ††P<0.005, control diet versus high-fiber group.