Comparison of the gut microbiome composition between Lawsonia intracellularis vaccinated and non-vaccinated pigs in a sub-clinically infected pig herd

Abstract

Lawsonia intracellularis (LI) infection in pigs can cause several clinical manifestations such as retarded growth, hemorrhagic diarrhea and mortality. Despite decades since the first isolation of the causative agent, still the underlying pathogenesis and virulence of LI is not fully understood yet. For the control of LI infection in the field, the use of antibiotics and vaccination with live-attenuated strain of LI has been implemented. Several studies have been done to determine the effect of vaccination on the prevention of clinical onset and improvement of productivity and impact on microbiome composition under experimental challenge conditions. However, little is known about the impact of natural subclinical LI infection, the most common form of this disease, on the gut microbiome of pigs compared to the vaccinated pigs. In the current study, the composition of the gut microbiome between LI vaccinated and non-vaccinated pigs was investigated to determine the efficacy of the vaccine on the host and the gut microbiome in the pig herd with LI sub-clinical infection. The increased productivity of vaccinated pigs was observed, and taxa related with the digestion showed higher relative abundance in the vaccinated pigs significantly. The results of this study suggest that vaccination with an oral live LI vaccine successfully increased the productivity of pigs by leading to a gut microbiome enriched with digestion-related taxa.