Live biotherapeutics in the post-antibiotic era: exploring the potential of probiotics to counter multidrug resistance.

Antimicrobial resistance (AMR) is a major global health threat that compromises the effectiveness of existing antibiotics and highlights the urgent need for alternative and adjunctive therapeutic strategies. Probiotics have emerged as potential adjunctive strategies because of their ability to modulate host-microbe interactions and influence microbial ecology without promoting resistance. This review examines the current evidence on the potential role of probiotics in combating multidrug-resistant organisms, based on findings from in vitro studies, animal models, and clinical investigations. The review is based on a narrative literature search of the PubMed database, covering studies published between 2020 and 2025, with earlier landmark studies. The mechanisms discussed include competitive exclusion of pathogens, the production of antimicrobial compounds, the enhancement of intestinal barrier function, and the modulation of host immune responses. In addition, probiotics are evaluated for their capacity to interfere with quorum sensing and inhibit biofilm formation, thereby reducing pathogen virulence and colonization. The review also addresses key limitations, including strain-specific variability, safety concerns in vulnerable populations, and the lack of standardized clinical protocols. Current evidence suggests that probiotics may represent a useful adjunct to existing AMR management strategies. However, their broader clinical application requires larger research to establish their efficacy and safety.