In this interview, Francisco Guarner, from Centro Médico Teknon in Barcelona, discusses the role of probiotics in the prevention of antibiotic-associated diarrhea, a topic he addressed at the 10th International Congress on Probiotics, Prebiotics, Postbiotics in Pediatrics. While antibiotics remain essential medicines and have profoundly improved human life expectancy, their use can also produce clinically relevant side effects, including diarrhea, particularly in vulnerable or hospitalized patients.

Guarner highlights that the most visible adverse effect, antibiotic-associated diarrhea, may not be the only outcome clinicians should consider. Each course of antibiotics can alter the gut microbiota and promote the overgrowth of bacterial taxa carrying antibiotic-resistance genes. Since the human gut represents one of the major reservoirs of these genes, antibiotic exposure may contribute to their expansion and potential transfer to other bacteria.

According to Guarner, future research should move beyond diarrhea as the main clinical endpoint and investigate whether probiotics can help limit the overgrowth of resistant bacteria and reduce the spread of antibiotic-resistance genes.