Effects of Lactobacillus plantarum on intestinal integrity and immune responses of chickens infected with Clostridium perfringens under the free-range or the specific pathogen free environment

Abstract

Background Necrotic enteritis, which is caused by Clostridium perfringens, has resulted in more than $2 billion losses in the poultry industry every year. Due to the ban of antibiotics in feed industry, alternatives like environment improvement and probiotics have been found to be effective as well. In our study, we aim to explore the protective effect of Lactobacillus plantarum on CP infected chickens in two environments. ResultsThe results showed that the Clostridium perfringens administration led to visible and histomorphological gut lesions. In the specific pathogen free or free-range system environment, dietary supplementation with LP obvious increased the ratio of intestinal villus height to crypt depth and the expression of MUC2 mRNA in ileum mucosa, then reduced the mRNA expression level of TNFα gene in the ileum mucosa. LP treatment significantly reduced the contents of total protein, total superoxide dismutase and glutamic oxaloacetic transaminase in serum of the chickens.Conclusions The specific pathogen free environment contributed to the recovery of pre-inflammation of the chickens, and free-range system environment contributed to the repair of damage in the later stages of chicken inflammation. Supplementation of LP in FRS environment was more conducive to the recovery of CP infected in chickens. BackgroundNecrotic enteritis (NE), which is caused by Clostridium perfringens (CP), is a disease of the major in the global poultry industry which has resulted in about 6-7 billion US dollars loss per year [25]. C. perfringens type A is a gram-positive, spore-forming, rod-shaped bacterium, which is the main pathogen that causes clinical and subclinical necrotic enteritis in poultry [40, 37]. The key factor for the development of NE is the change of gastrointestinal environment, which creates favorable conditions for the growth of CP. Antibiotics are considered to be effective measures to reduce the incidence of NE, but due to ban on feeding growth-promoting antibiotics in Europe, there has been an increase in the incidences of NE [14]. Environment improvement (intensive feeding patterns) and the extensive use of antibiotics have played an important role in preventing CP infection and the incidence of NE in the past decades [31]. Owing to the ban on the use of antibiotics in feed industry, This work was supported by National Natural Science Foundation of China (project no. 3146068; Beijing, P. R. China). Authors ContributionsNZ and TX designed the experiments and wrote the paper; LY, YC, JW, and MH performed the experiments and collected the samples. TX and LY analyzed the data. NZ and TX were responsible for the final content. All of the authors have read and approved the final manuscript.