Effects of ceftriaxone induced intestinal dysbacteriosis on lymphocytes in different tissues in mice

The close relationship between intestinal microflora and immune system has been confirmed, stimulus from intestinal flora plays an important role in the development of the immune system and its dynamic balance. Current research is still inadequate to determine how local bacteria in gut influence the whole body. In this study, influence of ceftriaxone sodium induced intestinal dysbacteriosis on local and overall immune function was investigated. We found that the beneficial bacteria decreased significantly compared with control after oral administration of ceftriaxone; Moreover, the proportion of T cells are higher and B cells are lower in the dysbacteriosis mice, activation and proliferation of T and B cells was decreased significantly in gut-associated lymphoid tissues (GALTs), such as Peyer's patches (PPs) and mesenteric lymph nodes(MLNs)with ceftriaxone treatment; The secreted sIgA in intestinal was reduced in dysbacteriosis mice than that of control as well. The similar results above are also shown on the spleen. In addition, the delayed type hypersensitivity (DTH) reaction decreased in dysbacteriosis mice. The present data suggested that intestinal microflora had impact on immune system by influencing the proportion and function of lymphocytes in PPS-MLN-spleen.