AUTHOR=Xue Mingyang , Wu Yeying , Hong Yizhan , Meng Yan , Xu Chen , Jiang Nan , Li Yiqun , Liu Wenzhi , Fan Yuding , Zhou Yong 

TITLE=Effects of dietary Bacillus amyloliquefaciens on the growth, immune responses, intestinal microbiota composition and disease resistance of yellow catfish, Pelteobagrus fulvidraco

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.1047351

DOI=10.3389/fcimb.2022.1047351

ISSN=2235-2988

ABSTRACT=<p>The influence of dietary probiotic <italic>Bacillus amyloliquefaciens</italic> on the growth performance, digestive enzyme activity, immune parameters and disease resistance of yellow catfish (<italic>Pelteobagrus fulvidraco</italic>) was evaluated. Commercial diet (C) or diet containing 10<sup>6</sup> cfu/g <italic>B. amyloliquefaciens</italic> (T) was fed for 4 weeks, and final weight (FW), specific growth rate (SGR) and feed conversion ratio (FCR) were improved (<italic>p&lt;</italic>0.05) in the T group. Dietary <italic>B. amyloliquefaciens</italic> increased protease and amylase activities in the digestive tract after 2 and 4 weeks, respectively. Respiratory burst (RB), plasma lysozyme (LZM) activity, total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity were also elevated (<italic>p&lt;</italic>0.05). Immune-related genes signal transducer and activator of transcription 1 (STATA-1), immunoglobulin M (IgM) and C-type lectin (CTL) were upregulated (<italic>p&lt;</italic>0.05), but interleukin-1 β (IL-1β) was not (<italic>p &gt;</italic>0.05). Intestinal microbiota analysis showed that the community structure was significantly different between the two groups; the relative abundance of <italic>Cetobacterium</italic> was increased but <italic>Plesiomonas</italic> was decreased in T. Moreover, challenge tests showed that the resistance of fish fed <italic>B. amyloliquefaciens</italic> against <italic>Aeromonas veronii</italic> and <italic>Edwardsiella ictaluri</italic> was significantly enhanced (<italic>p&lt;</italic>0.05). In conclusion, dietary supplementation of <italic>B. amyloliquefaciens</italic> can effectively improve the growth performance, digestive enzyme activity, immune responses, intestinal microbiota composition and disease resistance of yellow catfish.</p>