Residual antibiotics in the colonic lumen

Residual antibiotics in the colonic lumen represent the fraction of antimicrobial agents that reach the large intestine in an active form following oral or parenteral administration (de Gunzburg et al., 2018). While these drugs are intended to treat systemic or localized infections, their presence in the colon causes significant collateral damage by killing beneficial commensal bacteria (Buffie & Pamer, 2013). This disruption, known as dysbiosis, reduces colonization resistance and creates an environment conducive to the overgrowth of opportunistic pathogens like Clostridioides difficile (Lessa et al., 2015). Therapeutic strategies targeting these residues aim to neutralize or remove them specifically within the intestinal tract—either through enzymatic degradation or non-specific adsorption—without affecting the systemic efficacy of the antibiotic treatment (Kokai-Kun et al., 2017). By protecting the gut microbiome, these interventions help prevent antibiotic-associated diarrhea and the emergence of multi-drug resistant organisms (Theriva Biologics, 2023).

Other names

Fecal antibioticsIntestinal antibiotic residuesColonic antibiotic residuesUnabsorbed antibiotics

Sequestration via non-specific adsorption or enzymatic degradation (hydrolysis) of active antibiotic molecules within the intestinal lumen to prevent disruption of the commensal microbiota (de Gunzburg et al., 2018; Kokai-Kun et al., 2017).