Bacterial toxins in the gastrointestinal lumen

Bacterial toxins in the gastrointestinal (GI) lumen are critical virulence factors produced by pathogens such as Clostridioides difficile, Vibrio cholerae, and Shiga toxin-producing Escherichia coli (STEC) (Aktories & Barbieri, 2005, PMID: 15959477). These toxins, primarily exotoxins and enterotoxins, are released into the intestinal environment where they interact with the apical surface of enterocytes to disrupt cellular processes, including signal transduction, cytoskeleton integrity, and ion transport. For instance, C. difficile toxins TcdA and TcdB glucosylate Rho GTPases, leading to cell death and severe inflammation (colitis), while Cholera toxin induces massive fluid secretion via cAMP elevation. Therapeutic targeting of these intraluminal toxins represents an anti-virulence strategy that aims to neutralize or sequester the toxins before they can cause mucosal damage. This is achieved through the use of monoclonal antibodies like bezlotoxumab, which neutralizes TcdB (Wilcox et al., 2017, PMID: 28121551), or non-absorbable polymers and resins like cholestyramine that physically bind and facilitate the excretion of toxins (StatPearls, NBK499953). By focusing on the toxins rather than the bacteria themselves, these therapies can mitigate symptoms and prevent recurrence without exerting selective pressure for antibiotic resistance or further disrupting the commensal microbiota (Louie et al., 2006, PMID: 16841331).

Other names

EnterotoxinsIntestinal bacterial toxinsGastrointestinal exotoxinsBacterial enterotoxins

Neutralization of toxin activity, sequestration and fecal excretion of toxins, and inhibition of toxin-receptor binding.