We recently reported that the intraperitoneal inoculation of Lactobacillus helveticus SBT2171 inhibited the development of collagen-induced arthritis (CIA), a murine model of rheumatoid arthritis (RA). In the present study, we evaluated the effect of the oral administration of L. helveticus SBT2171 on CIA development and on the regulation of antigen-specific antibody production and inflammatory immune cells, which have been implicated in the development of RA. Both oral administration and intraperitoneal inoculation of L. helveticus SBT2171 reduced joint swelling, body weight loss, and the serum level of bovine type II collagen (CII)-specific antibodies in the CIA mouse model. The intraperitoneal inoculation also decreased the arthritis incidence, joint damage, and serum level of interleukin (IL)-6. In addition, the numbers of total immune cells, total B cells, germinal center B cells, and CD4+ T cells in the draining lymph nodes were decreased following intraperitoneal inoculation of L. helveticus SBT2171. These findings demonstrate the ability of L. helveticus SBT2171 to downregulate the abundance of immune cells and the subsequent production of CII-specific antibodies and IL-6, thereby suppressing the CIA symptoms, indicating its potential for use in the prevention of RA.

Background: We recently reported the suppressive effects of Lactobacillus helveticus SBT2171 (LH2171) on the proliferation and inflammatory cytokine production of primary murine immune cells in vitro. In this study, we investigated the effect of LH2171 on a murine pollen allergen- induced allergy model.Methods: Male BALB/c mice were fed a diet containing LH2171 (LH2171 group) or a diet not containing LH2171 (control group). Then, pollen allergy was induced by immunization with pollen extract emulsified in alum adjuvant and intranasal administration of pollen extract. To evaluate the anti-allergenic effect of LH2171, the antibody titer in plasma and expression of cytokines and transcription factors in immune tissues were analyzed by ELISA and qRT-PCR.Results: In the LH2171 group, the amounts of pollen-specific antibody and total IgE in plasma were significantly decreased compared with those in the control group. Proliferation and Th2 cytokine production were lower in the submandibular lymph node cells of the LH2171 group than in those of the control group. Moreover, in Peyer’s patches, the gene expression of Il10 and Foxp3 were increased in the LH2171 group.Conclusion: LH2171 has the ability to suppress production of allergy-related antibody and Th2 cytokines, which could be correlated with the induction of anti-inflammatory factors in the intestinal immune system.