Antibiotics Usage and Intestinal Microbiota

Abstract

Abstract Since the discovery of penicillin, antibiotics have made significant contributions to the treatment of infections in humans. However, as antibiotics are effective not only against pathogenic bacteria but also against all bacterial species that comprise the normal microbiota within the intestine, they can disrupt the balance in the composition of the intestinal microbiota, which causes antibiotic-associated diarrhea (AAD). In particular, infections caused by Clostridium difficile, a pathogenic bacterium known to cause AAD, can lead to pseudomembranous colitis or, in severe cases, death. AAD is primarily treated by halting the administration of the antibiotic thought to be causing the symptoms. After a diagnosis of C. difficile infection is confirmed, if symptoms persist and the patient's condition worsens despite ceasing the administration of the causative antibiotic, the administration of metronidazole or vancomycin may be considered. Moreover, several probiotics have been considered effective in the prevention and treatment of AAD.