Comparative analysis of the structural and compositional change of spotted sea bass (<em>Lateolabrax maculatus</em>) gut microflora following <em>Aeromonas veronii</em> infection and the effects of <em>Lactobacillus plantarum</em> on these changes

Abstract

Growing evidence suggests a close relationship between gut microbiota and infectious diseases. However, the specific role of gut microbiota in host-pathogen interactions during aquaculture-related infections remains poorly understood. This study investigated the diversity and composition of gut microbiota communities in <em>Aeromonas veronii</em>-infected <em>Lateolabrax maculatus</em> using high-throughput sequencing. The results revealed significant changes in the structure and composition of <em>L. maculatus</em> gut microbiota after <em>A. veronii</em> infection. Over time, Bacteroidetes and Firmicutes decreased significantly, while Proteobacteria increased significantly after <em>A. veronii</em> infection. Most intestinal bacteria showed a decline in abundance over time, with probiotics (such as <em>Lactobacillus</em>) experiencing a significant decrease and pathogens (such as <em>Aeromonas</em>) showing a significant increase. Conversely, no differences were observed in the structure and composition of gut microbiota between healthy <em>L. maculatus</em> and those infected with <em>A. veronii</em> after treatment with <em>Lactobacillus plantarum</em>; no changes in relative abundances of other bacterial phyla or genera except for <em>Aeromonas</em>. Furthermore, intestinal flora's structural diversity and composition differed significantly from untreated <em>L. maculatus</em> infected with <em>A. veronii</em>. These findings suggest alterations in the structure and composition of gut microbiota following <em>A. veronii</em> infection. <em>L. plantarum</em> can maintain a dynamic balance within the intestinal flora, reducing the potential risk of pathogen infections.