Immunosuppressive Activity of Goat Kefir in a Rat Model with Bleomycin-induced Pulmonary Fibrosis

Objective: This study aimed to investigate the immunomodulatory capacity of goat kefir on pulmonary fibrosis rat model. Material and Methods: Twenty-five male rats were randomly divided into five groups: one group only received induction with bleomycin (0.3 mg/rat) to induce pulmonary fibrosis; three groups were treated with different doses (2.5, 3.5, and 4.5 mL/200 g BW) of goat kefir, following the induction with bleomycin, for 30 days; and one group served as negative control, did not receive bleomycin induction as well as kefir. On day 30, all the animals were sacrificed. Plasma levels of TGF-β, IL-4, and IFN-y were measured using the ELISA method, and the expression of α-SMA in myofibroblast cells was examined with the help of immunohistochemistry assay. Results: Induction with bleomycin significantly elevated the expressions of TGF-β, IL-4, and IFN-y in comparison to the control group. Following the administration of kefir (3.5 and 4.5 mL/200 g BW), the concentration of TGF-β was significantly decreased (p<0.05); whereas, the concentration of IFN-y increased slightly (p<0.05) only in the group that received the 4.5 mL/200 g BW dose of kefir. In contrast, IL-4 exhibited increasing levels with higher doses of kefir (p<0.05). The expression of α-SMA in myofibroblasts showed a tendency to decline following the administration of kefir, although this decline was not statistically significant. Conclusions: Goat kefir caused a reduction in the TGF-β levels in fibrosis conditions; however, the kefir elicited an immunosuppressive effect during the progression of the pulmonary fibrosis.