Dietary Lactobacillus plantarum alleviated Salmonella Typhimurium infection and suppressed Jak/Stat pathway in rabbits

Abstract

This study aimed to investigate the effect of a Lactobacillus plantarum DPP8 supplementation on the growth performance, pathogenic invasion, inflammation and pathogen resistance signal pathway in rabbits infected with Salmonella Typhimurium (S. Typhimurium). The treatments included a negative control, a positive control with an S. Typhimurium infection and a positive control plus DPP8 at 10<sup>6</sup>, 10<sup>8</sup> or 10<sup>10</sup> cfu/kg of diet using 300 weaned rabbits. The results showed that supplementing with DPP8 improved (P < 0.05) the feed intake, body weight gain and feed efficiency compared to the positive control. Also, DPP8 decreased (P < 0.05) the S. Typhimurium colonisation and translocation, serum IL-1β, IL-6 and TNF-α, and intestinal mucosa mRNA expressions of the inflammatory mediators Janus kinase (Jak) 2, the signal transducer and activator of transcription (Stat) 1 and 3 at 7 and 14 d post administration. The dose analysis of DPP8 showed linear increases (P ≤ 0.007) in the feed intake and body weight gain, but linear decreases (P ≤ 0.022) in the S. Typhimurium loads, IL-1β, IL-6 and Jak2. It is concluded that Lactobacillus plantarum DPP8 can be used as a supportive probiotic against an S. Typhimurium infection and it possibly plays a direct or indirect role in the downregulation of the Jak/Stat pathway in rabbits.