Oral Administration of viable and heat-killed Lactic Acid Bacteria to Reduce the Salmonella Invasion and Inflammation of Broiler Chicks

• Main Authors: Chun-Li Lin, 林峻立
• Other Authors: 曾浩洋
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/67774519738290870212

碩士 === 弘光科技大學 === 食品科技所 === 101 === Salmonella is one of the major causes of food-borne bacterial gastroenteritis worldwide. Sources of human Salmonella infection include consumption of undercooked poultry or eggs and egg-containing products. Inflammation is one of the first reactions against Salmonella infection, but the overreaction to the infection will lead to the dysfunction of the tissues and organs. In this study, four strains of lactic acid bacteria (LAB), i.e., Lactobacillus acidophilius LASW, L. plantarum LPL05, L. fermentum LF33, Entercoccus faecium TM39, either viable or heat-killed (HK), a multistrain formula (MF) consisted of 4 heat-killed lactic acid bacteria and a powder formulation consisted of 4 viable LAB were used to investigate their effects against Salmonella invasion and inflammation. One day old chicks were fed with viable LAB, HK-LAB or HK-MF from day 1 to day 3. On day 4, chicks were challenged with S. Typhimurium. The livers, spleens, cecal tonsils and cecal contents of chicks were then removed and the numbers of Salmonella on day 3 and 6 post-infection were determined. Moreover, the levels of proinflammatory cytokines, i.e., interleukin (IL)-1β, IL-6, interferon (IFN)-γ and anti-inflmmatory cytokine, i.e., IL-10, in cecal tonsils were measured by reverse transcription real-time quantitative PCR (RT-Q PCR). Regarding the effects against Salmonella invasion, all LAB used in this study could reduce the numbers of Salmonella by approximately 1-2 logarithmic scales. Multistrain formula even have the better performance (p<0.05). For the anti-inflammatory effects, chicks fed with LAB showed lower levels of proinflammatory cytokines compared to the controls on day 3 post-infection (p<0.05). In addition, LAB were formulated into a powder form to be wed in field trials. Feeds containing either 1%/kg or 0.1%/kg of the aforementimed powder were provided ad libitum. On day 4, chicks were challenged. The numbers of Salmonella and the expression of cytokines in the livers, spleens, cecal tonsils and cecal contents of chicks were determined on day 3 and 6 post infection. Similar results were obtained in comparison to those by oral administration. Feeds containg 1%/kg powder exert better immunomodulatory effects and are more effection against Salmonella invasion (p<0.05). Furthermore, beneficial effects including improrement of growth rate and enrichment of probiotics in chicken intestines were observed in chicks fed with feeds containg 1%/kg powder. These results suggest that LAB, HK-LAB, HK-MF or powder formulation exert immunomodulatory effects and could be used against Salmonella invasion.