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

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 Aeromonas veronii-infected Lateolabrax maculatus using high-throughput sequencing. The results revealed significant changes in the structure and composition of L. maculatus gut microbiota after A. veronii infection. Over time, Bacteroidetes and Firmicutes decreased significantly, while Proteobacteria increased significantly after A. veronii infection. Most intestinal bacteria showed a decline in abundance over time, with probiotics (such as Lactobacillus) experiencing a significant decrease and pathogens (such as Aeromonas) showing a significant increase. Conversely, no differences were observed in the structure and composition of gut microbiota between healthy L. maculatus and those infected with A. veronii after treatment with Lactobacillus plantarum; no changes in relative abundances of other bacterial phyla or genera except for Aeromonas. Furthermore, intestinal flora's structural diversity and composition differed significantly from untreated L. maculatus infected with A. veronii. These findings suggest alterations in the structure and composition of gut microbiota following A. veronii infection. L. plantarum can maintain a dynamic balance within the intestinal flora, reducing the potential risk of pathogen infections.