Modulation of gut microflora of broilers by microbially produced dextran and levan exopolysaccharides

In the research work presented in this manuscript, we have used two types of prebiotic exoploysaccharides (EPSs: dextran and levan) produced by bacteria, isolated from camel gut and plant rhizosphere, for the modulation of microbial populations in the gut of broiler chicken. We found that both of these EPSs, when fed to the birds along with feed, inhibited the growth of Salmonella in the small intestine of broilers. Additionally, dextran and levan inhibited the growth of E. coli and Enterococcus, respectively. Also, these EPSs were found to enhance the populations of lactic acid bacteria in the intestine of prebiotic fed birds as compared to controls.本论文所呈现的研究工作中，我们采用了两类由细菌产生的益生元胞外多糖（exopolysaccharides, EPSs）：葡聚糖（dextran）与果聚糖（levan），这些菌株分别从骆驼肠道及植物根际中分离得到，用于调节肉鸡肠道的微生物菌群。研究发现，将这两种EPSs添加至饲料中饲喂肉鸡后，均可抑制肉鸡小肠内沙门氏菌（Salmonella）的增殖。此外，葡聚糖与果聚糖可分别抑制大肠杆菌（Escherichia coli, E. coli）与肠球菌（Enterococcus）的增殖。同时，与对照组相比，饲喂该类胞外多糖的肉鸡肠道内乳酸菌（lactic acid bacteria）的菌群丰度显著提升。