Effects Of Bacillus Sp. As Feed Additive On The Epithelial Structures And Intestinal Mucosal Immunity Of Mice

Effects of Bacillus sp. as feed additive on the epithelial structures intestinal mucosal immunity of mice was studied. Nity-six healthy weaning mice were divided into 4 groups. Control group mice were fed the basic diet; PAb04 group mice were fed the diet with 10~6cfu/g of B. subilits PAb04; PAS38 group mice were fed the diet with 10~6cfu/g of B. cerecus PAS38; Antibiotic group mice were fed the diet with 20u/g of Oxyteracycline. Eight mice in each group were killed per time-point on day 20, 40, 60-day-old. The distribution and change of somatostatin(SS)-positive cells, IgA-positive cells, IEL, CD4+ and CD8+ T cells and mast cells induodenum and jejunum of mice were measured.1. H.E staining method was adopted to study the change of mucosa thickness and villus length in mouse small intestinal. The results showed that Bacillus sp. as additive of mice could increase mucosa thickness and villus length in mouse small intestinal.2. H.E staining method was used to study the change of IEL in mouse small intestinal. The results showed that Bacillus sp. as praperation of mice to increase the number of IEL in mouse small intestinal increased, the number of IEL in duodenum and jejunum of PAS38 group increased significantly (P＜0.05) comparing to control group and antibiotic group at the 40th day; Comparing to control group the number of IEL in duodenum and jejunum of PAS38 group increased significantly (P＜0.05) at the 60th day. The results suggest that Bacillus sp. PAS38 as additive of mice can increase the number of IEL in mouse small intestinal.3. The changes of the number of IgA-positive cells, CD4+ and CD8+ T cells in mouse small intestinal were studied by SABC immunohistochemistry. The results showed that in the all sixty days the number of IgA-positive cells, CD4+ and CD8+ T cells in duodenum and jejunum of PAB04 group increased significantly (P＜0.05) comparing to control group; Comparing to control group the number of IgA-positive cells, CD4+ and CD8+ T cells in duodenum and jejunum of PAS38 group increased significantly (P＜0.01); the number of IgA-positive cells, CD4+ and CD8+ T cells in duodenum and jejunum of PAS38 group increased significantly compared to antibiotic group. The results suggest that Bacillus sp. PAS38 as additive of mice can increase the number of IgA-positive cells, CD4+ and CD8+ T cells, thus mucosal immunization is promoted.4. Toluidine blue staining method was used to study the change of mast cells numble in mouse small intestinal. The results showed that the number of mast cells in jejunum of PAb04 group increased significantly (P＜0.05) and the number of mast cells in jejunum of PAS38 group increased significantly (P＜0.01) compared to control group at the 20th day; Comparing to antibiotic group the number of mast cells in jejunum of PAb04 group and PAS38 group increased significantly (P＜0.01) at the 20th day; the number of mast cells in duodenum of PAS38 group increased significantly (P＜0.05) compared to control group at the 40th day; the number of mast cells in duodenum of PAb04 group increased significantly (P＜0.05) compared to control group at the 60th day; the number of mast cells in duodenum of PAS38 group increased significantly (P＜0.01) compared to control group at the 60th day; Comparing to control group the number of mast cells in jejunum PAb04 group and PAS38 group increased significantly (P＜0.01).Our results suggest that the number of mast cells might reflect the digestive mucosal immunization.5.The changes of the number of SS-positive cells in mouse small intestinal were studied by SABC immunohistochemistry.The results showed that the number of SS-positive cells in duodenum of PAS38 group increased significantly (P＜0.05) compared to control group at the 20th day,Comparing to antibiotic group the number of SS-positive cells in duodenum of PAb04 group and PAS38 group increased significantly (P＜0.01)at the 20th day; the number of SS-positive cells in jejunum of PAb04 group and PAS38 group increased significantly (P＜0.01) compared to control group and antibiotic group at the 20th day, Comparing to PAb04 group the number of SS-positive cells in jejunum of PAS38 group increased significantly (P＜0.05) at the 20th day; the number of SS-positive cells in duodenum of PAb04 group and PAS38 group increased significantly (P＜0.05) compared to antibiotic group at the 40th day; Comparing to control group the number of SS-positive cells in duodenum of PAb04 group increased significantly (P＜0.05)and the number of SS- positive cells in duodenum of PAS38 group increased significantly (P＜0.01) at the 40th day; the number of SS- positive cells in jejunum of PAS38 group increased significantly (P＜0.01) compared to control group at the 40th day.The results suggest that Bacillus sp. PAS38 as feed of mice to increase mucosal immunity promoted.