Bacterial and host-derived toxins and solutes in the gastrointestinal lumen

Bacterial and host-derived toxins and solutes in the gastrointestinal lumen represent a broad pharmacological target consisting of various deleterious molecules produced by the gut microbiota or the host's own metabolic processes. This target includes uremic toxin precursors like indole and p-cresol, bacterial exotoxins such as those from Clostridioides difficile, and host-derived solutes like bile acids and phosphate (PMID: 29358678, 21415311). In health, these substances are typically managed by the gut barrier and systemic excretion; however, in diseases like chronic kidney disease (CKD) or hepatic encephalopathy, they accumulate and contribute to systemic toxicity and organ damage (StatPearls). Drugs targeting this lumen work primarily through non-specific adsorption or specific sequestration to prevent the absorption of these solutes into the bloodstream. For instance, AST-120 is an oral adsorbent used to delay CKD progression by binding indole, thereby reducing the systemic levels of the cardiorenal toxin indoxyl sulfate (PMID: 29358678). Other agents like sevelamer or cholestyramine target specific solutes like phosphate or bile acids to treat hyperphosphatemia and cholestatic pruritus, respectively (FDA Labels). The primary therapeutic challenge with this target is the lack of selectivity, which can lead to the unintended binding of essential nutrients or co-administered medications.

Other names

Gut-derived uremic toxinsIntestinal luminal solutesGI toxinsEnteric toxinsGastrointestinal luminal environment

Adsorption and sequestration