AUTHOR=Tang Qingsong , Xu E. , Wang Zhikang , Xiao Mingfei , Cao Shuting , Hu Shenglan , Wu Qiwen , Xiong Yunxia , Jiang Zongyong , Wang Fengying , Yang Geling , Wang Li , Yi Hongbo 

TITLE=Dietary Hermetia illucens Larvae Meal Improves Growth Performance and Intestinal Barrier Function of Weaned Pigs Under the Environment of Enterotoxigenic Escherichia coli K88

JOURNAL=Frontiers in Nutrition

VOLUME=8

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.812011

DOI=10.3389/fnut.2021.812011

ISSN=2296-861X

ABSTRACT=<p>The aim of this study was to evaluate the effect of <italic>Hermetia illucens</italic> larvae meal (HI) on the growth performance and intestinal barrier function of weaned pigs. To achieve this, 72 weaned pigs [28-day-old, 8.44 ± 0.04 kg body weight (BW)] were randomly assigned to three dietary treatments: basal diet (negative control, NC), zinc oxide-supplemented diet (positive control, PC), and HI-supplemented diet [100% replacement of fishmeal (FM), HI], for 28 days in the presence of enterotoxigenic <italic>Escherichia coli</italic> (ETEC). The results showed that HI and PC increased (<italic>p</italic> &lt; 0.05) the average daily gain (ADG) and average daily feed intake (ADFI) of weaned pigs from day 1 to 14, and decreased diarrhea incidence from day 1 to 28. Additionally, HI increased (<italic>p</italic> &lt; 0.05) claudin-1, occludin, mucin-1 (<italic>MUC-1</italic>), and MUC-2 expression, goblet cell number, and secretory immunoglobulin A (sIgA) concentration in the intestine of weaned pigs. Compared with NC, HI downregulated (<italic>p</italic> &lt; 0.05) interleukin-1β (<italic>IL-1</italic>β) and <italic>IL-8</italic> expression, and upregulated <italic>IL-10</italic>, transforming growth factor-β (<italic>TGF-</italic>β), antimicrobial peptide [porcine β defensin 1 (<italic>pBD1</italic>), <italic>pBD2</italic>, protegrin 1-5 (<italic>PG1-5</italic>)] expression in the jejunum or ileum. Moreover, HI decreased (<italic>p</italic> &lt; 0.05) toll-like receptor 2 (TLR2), phosphorylated nuclear factor-κB (p-NF-κB), and phosphorylated mitogen-activated protein kinase (p-MAPK) expression, and increased sirtuin 1 (SIRT1) expression in the ileum. Additionally, HI increased histone deacetylase 3 (HDAC3) expression and acetylation of histone 3 lysine 27 (acH3k27) in the ileum. Furthermore, HI positively influenced the intestinal microbiota composition and diversity of weaned pigs and increased (<italic>p</italic> &lt; 0.05) butyrate and valerate concentrations. Overall, dietary HI improved growth performance and intestinal barrier function, as well as regulated histone acetylation and TLR2-NF-κB/MAPK signaling pathways in weaned pigs.</p>