AUTHOR=Yang Hang , Yuan Quan , Rahman Mohammad Mizanur , Lv Weiwei , Huang Weiwei , Hu Wei , Zhou Wenzong 

TITLE=Comparative studies on the intestinal health of wild and cultured ricefield eel (Monopterus albus)

JOURNAL=Frontiers in Immunology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1411544

DOI=10.3389/fimmu.2024.1411544

ISSN=1664-3224

ABSTRACT=<p>Fish intestinal health under intensive aquaculture mode plays an important role in growth, development, and immune function. The present study was aimed to systematically investigate the differences of intestinal health between wild and cultured <italic>Monopterus albus</italic> by biochemical parameters, histomorphology, and molecular biology. A total of 15 healthy <italic>M. albus</italic> per group, with an average body weight of 45 g, were sampled to analyze intestinal health parameters. Compared with wild fish, the cultured <italic>M. albus</italic> in the foregut had lower trypsin, lipase, SOD, CAT, T-AOC, and GSH-Px activities (<italic>P</italic> &lt; 0.05) and higher amylase activity and MDA content (<italic>P</italic> &lt; 0.05). The villus circumference and goblet cells in the cultured group were significantly lower than those in the wild group (<italic>P</italic> &lt; 0.05). In addition, the cultured fish showed lower relative expression levels of <italic>occludin</italic>, <italic>zo-1</italic>, <italic>zo-2</italic>, <italic>claudin-12</italic>, <italic>claudin-15</italic>, <italic>mucin5</italic>, <italic>mucin15</italic>, <italic>lysozyme</italic>, <italic>complement 3</italic>, <italic>il-10</italic>, <italic>tgf-β1</italic>, <italic>tgf-β2</italic>, and <italic>tgf-β3</italic> (<italic>P</italic> &lt; 0.05) and higher <italic>il-1β</italic>, <italic>il-6</italic>, <italic>il-8</italic>, <italic>tnf-a</italic>, and <italic>ifnγ</italic> mRNA expressions than those of wild fish (<italic>P</italic> &lt; 0.05). In terms of gut microbiota, the cultured group at the phylum level displayed higher percentages of <italic>Chlamydiae</italic> and <italic>Spirochaetes</italic> and lower percentages of <italic>Firmicutes</italic>, <italic>Bacteroidetes</italic>, <italic>Actinobacteria</italic>, <italic>Cyanobacteria</italic>, and <italic>Verrucomicrobia</italic> compared to the wild group (<italic>P</italic> &lt; 0.05). At the genus level, higher abundances of <italic>Pseudomonadaceae_Pseudomonas</italic> and <italic>Spironema</italic> and lower abundances of <italic>Lactococcus</italic> and <italic>Cetobacterium</italic> were observed in the cultured group than in the wild group (<italic>P</italic> &lt; 0.05). To our knowledge, this is the first investigation of the intestinal health status between wild and cultured <italic>M. albus</italic> in terms of biochemistry, histology, and molecular biology levels. Overall, the present study showed significant differences in intestinal health between wild and cultured <italic>M. albus</italic> and the main manifestations that wild <italic>M. albus</italic> had higher intestinal digestion, antioxidant capacity, and intestinal barrier functions than cultured <italic>M. albus.</italic> These results would provide theoretical basis for the subsequent upgrading of healthy aquaculture technology and nutrient regulation of intestinal health of cultured <italic>M. albus.</italic></p>