Intestinal and Mucosal Microbiomic Response to Oral Challenge of Enterotoxigenic Escherichia Coli in Weaned Pigs
Abstract Enterotoxigenic Escherichia coli (ETEC) is closely associated with diarrhoea in children in resource-limited countries and of travellers’ diarrhoea. This study aims to investigate the change of ileal mucosal microbiome and ileal protein expression as well as their correlation in pigs by E. coli K88 (ETEC). Seven weaned male pigs were orally given 1 ×109 CFU of ETEC (ETEC, n = 7), and the other seven received saline (CON, n = 7). Ileal tissues were obtained 48 h after the ETEC challenge for both proteomic and mucosal microbiomic analyses. Nine proteins were altered in expression level in the ETEC group, including decreased expression of FABP1 and FABP6 involved in bile acid circulation. TLR-9 mediated pathway was also affected at transcription level with increased expression of SIGIRR and MyD88. Correlation analysis revealed correlations between the ileal proteins and mucosal bacterial taxa, including the positive correlation between Lactobacilli and PPP3CA (r = 0.9, p < 0.001), and negative correlation between Prevotella with CTNND1 (r = -0.7, p < 0.01). In conclusion, ETEC infection caused inflammation and impaired the circulation of bile acids, and the mucosal microbiome may affect the expression of intestinal proteins. Further studies are needed for exact roles of these affected processes in the pathogenesis of ETEC-triggered diarrhoea.