Use of the potential probiotic strain Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers

Campylobacteriosis is the most frequently reported zoonotic disease in humans in the EU since 2005. As chicken meat is the main source of contamination, reducing the level of Campylobacter in broiler chicken will lower the risk to consumers. The aim of this project was to evaluate the ability of Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers and to investigate the mechanisms that could be involved. Thirty broilers artificially contaminated with C. jejuni were treated by oral gavage with MRS broth or a bacterial suspension (10⁷CFU) of Lb. salivarius SMXD51 (SMXD51) in MRS broth. At 14 and 35days of age, Campylobacter and Lb. salivarius loads were assessed in cecal contents. The impact of the treatment on the avian gut microbiota at day 35 was also evaluated. At day 14, the comparison between the control and treated groups showed a significant reduction (P<0.05) of 0.82 log. After 35days, a significant reduction (P<0.001) of 2.81 log in Campylobacter loads was observed and 73% of chickens treated with the culture exhibited Campylobacter loads below 7log₁₀CFU/g. Taxonomic analysis revealed that SMXD51 treatment induced significant changes (P<0.05) in a limited number of bacterial genera of the avian gut microbiota and partially limited the impact of Campylobacter on Anaerotruncus sp. decrease and Subdoligranulum sp. increase. Thus, SMXD51 exhibits an anti-Campylobacter activity in vivo and can partially prevent the impact of Campylobacter on the avian gut microbiota.