Time course of the effects of oral administration of varying dosages of LcZhang on immunoglobulin production in serum and in the intestines. ELISA detected sIgA level in intestine content and IgG level in serum at every 5 days after oral administration of live LcZhang. A: sIgA levels in intestine content; B: IgG levels in serum. Control refers 2.0 ml PBS (open squares); low dose represents 2.0 ml live cells with density of 0.5 × 109 cells/ml (solid squares); medium dose represents 2.0 ml live cells with density of 1 × 109 cells/ml (open triangles); high dose represents 2.0 ml live cells with density of 2 × 109 cells/ml (solid triangles). Five mice were sacrificed in every 5 days. Data are means ± S.D. (n = 5). Error bars represent S.D. *P < 0.05; **P < 0.01.