Screening Traditional Foods for the Prevention of Enterotoxigenic Escherichia coli K88ac (F4ac) Attachment to IPEC-J2 Cells

Enterotoxigenic Escherichia coli (ETEC) is the major diarrhoea-causing pathogen world-wide. Fimbria–receptor recognition is the primary step when attachment of ETEC to the intestine occurs. This study aims to evaluate the potential of some traditional foods, particularly those rich in β-glucans, as analogues for fimbriae or receptors in reducing ETEC colonisation. The adhesion test (AT) demonstrated that aqueous extracts of highland barley (EHB), black rice (EBR) and little millet (ELT) at concentrations of 2% and 1% could attach to more ETEC K88ac (p < 0.001), as well as aqueous extracts of shiitake (EST) (p < 0.01). The competition test (CT) revealed that EHB and EST significantly prevented ETEC K88ac from adhering to intestinal epithelial cells (IPEC-J2) at 2% (p < 0.01) and 1% (p < 0.05). In the Exclusion Test (ET) and the displacement test (DT), the food samples were unable to impair ETEC colonisation in terms of blocking receptors or removing attached pathogens. These results demonstrate how some traditional foods such as highland barley and shiitake contain bioactive compounds that interfere with the attachment of ETEC to the intestinal epithelium, and their potential in the prevention and treatment of ETEC diarrhoea.