The effects of orally administered Bacillus coagulans and inulin on prevention and progression
of rheumatoid arthritis in rats
Sammanfattning
Background: Probiotics have been considered as an approach to addressing the consequences
of different inflammatory disorders. The spore-forming probiotic strain Bacillus coagulans has
demonstrated anti-inflammatory and immune-modulating effects in both animals and humans. The
prebiotic inulin also potentially affects the immune system as a result of the change in the
composition or fermentation profile of the gastrointestinal microbiota.
Objective: In the present study, an in vivo model was conducted to investigate the possible
influences of probiotic B. coagulans and prebiotic inulin, both in combination and/or separately, on
the downregulation of immune responses and the progression of rheumatoid arthritis (RA), using
arthritis-induced rat model.
Design: Forty-eight healthy male Wistar rats were randomly categorized into six experimental groups
as follows: 1) control: normal healthy rats fed with standard diet, 2) disease control (RA): arthritis-
induced rats fed with standard diet, 3) prebiotic (PRE): RA+ 5% w/w long-chain inulin, 4) probiotic
(PRO): RA+ 109 spores/day B. coagulans by orogastric gavage, 5) synbiotic (SYN): RA+ 5% w/w
long-chain inulin and 109 spores/day B. coagulans, and 6) treatment control: (INDO): RA+ 3 mg/kg/day
indomethacin by orogastric gavage. Feeding with the listed diets started on day 0 and continued to
the end of study. On day 14, rats were injected with complete Freund’s adjuvant (CFA) to induce
arthritis. Arthritis activity was evaluated by the biochemical parameters and paw thickness.
Biochemical assay for fibrinogen (Fn), serum amyloid A (SAA), and TNF-a and alpha-1-acid
glycoprotein (a1AGp) was performed on day 21, 28, and 35 (7, 14 and 21 days post RA induction),
respectively.
Results: Pretreatment with PRE, PRO, and SYN diets significantly inhibits SAA and Fn production in
arthritic rats (P < 0.001). A significant decrease in the production of pro-inflammatory cytokines, such
as TNF-a, was seen in the PRE, PRO, and SYN groups (P < 0.001), which was similar to the anti-
inflammatory effect of indomethacin. Furthermore, no significant anti-inflammatory effects were
observed following different treatments using a1AGp as an RA indicator. Pretreatment with all
supplied diets significantly inhibited the development of paw swelling induced by CFA (P < 0.001).
Conclusion: The results of this study indicate that the oral intake of probiotic B. coagulans and
prebiotic inulin can improve the biochemical and clinical parameters of induced RA in rat.