Bifidobacterium longumstrain change CD4 and CD8 T cells profile in inflammatory bowel disease induced in mice (MPF6P.663)

Abstract Probiotics are defined as a live microorganisms which, when given to the host, beneficially affect the properties of the natural microflora. In our earlier study, we found reduction of the amount of CD8+ and CD4+ T cells in PP in mice fed with different commercial probiotic preparations. Nevertheless, some of them significantly induced CD8+CD4+ cells, most effectively enhanced CD4+and lowered CD8+ cells in splenocytes, but later, this activating effect was reduced and changed. The presented study compared the effect of potentially probiotic Bifidobacterium longumstrain on DSS - induced colitis in older mice. Colitis was induced for 7 days via administration of 2.5% DSS in drinking water. BALB/c mice were gavaged 200 µl of the probiotic preparation (5x109 CFU/mL) or physiological saline, for 14 days. Feeding mice with B. longum significantly increased CD4+ and decreased CD4+CD8+ T cells in MLNs. Significant reduction of CD4+CD8+ T cells was also observed in PPs, however, with no changes in the other populations tested. Splenocytes responded to bacterial feeding by significant increasing both CD4+ and CD8+ T cells, whereas, lymphocytes from peripheral lymph nodes respond by further increase of CD4+, but decrease of CD8+ cells. No changes in lymphocytes phenotyping in the two tested groups were observed in the serum. The experiment showed that the strain tested changed T lymphocyte profile, and further studies are necessary to evaluate its safety and effectiveness.