The effect of Campylobacter jejuni challenge on the ileal microbiota and short-chain fatty acids at 28 and 35 days of age

Abstract

Acetate is a short-chain fatty acid (SCFA) that plays an important role in maintaining intestinal barrier integrity. Campylobacter jejuni (C. jejuni) infection is hypothesised to decrease the presence of acetate-producing bacteria and, consequently, the overall acetate concentration in the ileum, leading to an impaired intestinal barrier. This study aimed to characterise the effect of the C. jejuni challenge on the ileal microbiota and SCFAs concentration in broilers. Sixty broiler chicks were randomly assigned to control and challenge treatments, each with six replications and five birds per replicate. At 21 days of age, birds were inoculated with PBS (control), or 1 × 108 CFU/bird C. jejuni in the challenge group. Body weight, feed intake and feed conversion ratio were measured weekly. Ileal mucus and contents were collected on days 28 and 35 for microbiome and SCFA analysis. C. jejuni challenge didn’t affect body weight, feed intake and feed conversion ratio at days 28 and 35 compared to the control group. C. jejuni didn’t affect alpha diversity compared to the control group. C. jejuni didn’t alter microbial function nor the relative abundances of the phyla, families, genera and species compared to the control group; however, C. jejuni decreased the ileal concentration of acetate on days 28 (p = .09) and 35 (p = .002) compared to the control group. In conclusion, the C. jejuni challenge didn’t alter microbial composition or function and except for the shifts in acetate concentration, it had minimal impact on birds’ intestinal environment, highlighting the near-commensal nature of C. jejuni in broilers.