Characterizing the Effect of Campylobacter jejuni Challenge on Growth Performance, Cecal Microbiota, and Cecal Short-Chain Fatty Acid Concentrations in Broilers

Simple Summary: Campylobacter jejuni (C. jejuni) is the most common cause of bacterial gastroenteritis in humans worldwide. Poultry and poultry products serve as major reservoirs for this bacterium. In poultry, C. jejuni colonizes the ceca of broilers with a high load without compromising the bird's growth. Understanding the interaction between the host and the microbe is essential for the development of innovative strategies to control C. jejuni in poultry. The objective of this study was to understand the impact of C. jejuni on bird growth, cecal microbiota, and cecal short-chain fatty acid concentration. Throughout our study, C. jejuni did not impact the bird's performance. However, the C. jejuni challenge led to a decrease in the number of observed bacteria compared to the control group. At the species level, the C. jejuni challenge decreased the relative abundance of beneficial bacteria, such as Sellimonas intestinalis, and increased the relative abundance of Faecalibacterium sp002160895 compared to the control group. Despite the changes in the microbial composition, the C. jejuni challenge did not change the microbial function or the concentration of short fatty acids in the ceca compared to the control group. In conclusion, C. jejuni infection in broilers can alter the microbial composition without compromising the bird's performance. This study aimed to understand the effect of C. jejuni challenge on the cecal microbiota and short-chain fatty acid (SCFA) concentration to form a better understanding of the host-pathogen interaction. Sixty broilers were randomly allocated into two treatments: control and challenge. Each treatment was replicated in six pens with five birds per pen. On day 21, birds in the challenge group were orally gavaged with 1 x 108 C. jejuni/mL, while the control group was mock challenged with PBS. The C. jejuni challenge had no effect on body weight, feed intake, and feed conversion ratio compared to the control group. On day 28, the C. jejuni challenge decreased the observed features and Shannon index compared to the control group. On the species level, the C. jejuni challenge decreased (p = 0.02) the relative abundance of Sellimonas intestinalis on day 28 and increased (p = 0.04) the relative abundance of Faecalibacterium sp002160895 on day 35 compared to the control group. The C. jejuni challenge did not change the microbial function and the cecal concentrations of SCFA on days 28 and 35 compared to the control group. In conclusion, C. jejuni might alter the gut microbiota's composition and diversity without significantly compromising broilers' growth.