The immunomodulatory effects of paraprobiotic mixtures derived from novel probiotic isolates in dextran sodium sulfate-induced colitis in mice via MAPK pathway

Introduction: The positive effects of paraprobiotic which are inviable components derived from probiotic strains, in a colitis model have been reported in some studies, although the precise mechanisms behind these effects have not been fully elucidated. Therefore, the objective of this study was to evaluate the beneficial anti-inflammatory effect of paraprobiotics derived from our native Bifidobacterium and Lactobacillus spp. In a colitis model as a safer product in comparison to probiotic, through the MAPK signaling pathway. Methods: Colitis was induced by orally administering 2 % DSS to C57BL/6 mice. Alongside DSS, a mixture of paraprobiotics was administered via gavage. After two weeks, the mice were assessed using Disease Activity Index and histopathological scores. Moreover, the colonic specimens were analyzed to determine the expression of inflammatory markers using qRT-PCR. Results: The consumption of DSS resulted in alterations in body weight and the structure of the colon. However, the administration of the paraprobiotics mixture exhibited a significant improvement in DSS-induced colitis in mice through a reduction in body weight loss and an increase in the colon length. Furthermore, there were decreases in DAI and histopathological scores observed following this treatment. The administration of paraprobiotics led to a reduction in inflammation by downregulating the expression of MAPK-related genes that were induced by DSS. Conclusion: The findings demonstrate that presented paraprobiotic have a protective effect in a mouse model of DSS-induced colitis by mitigating the inflammatory response. The present study provides support for the development of paraprobiotics as a safe alternative therapeutic agent for IBD.