Clostridioides (formerly Clostridium) difficile is a spore-forming, Gram-positive anaerobic bacillus that is a cause of 15 to 25% of all episodes of antibiotic-associated diarrhea.8 It is commonly found at low levels within the commensal microbiota of the human gut.9 Among those organisms, it is considered to be pathobiont, meaning that within its indigenous community, it is benign; however, when homeostasis is disrupted, it acts as a pathogen.9 Factors that can alter this homeostatic balance include antibiotic treatment, tissue damage, changes to diet, and immune deficiencies.10
C. difficile infection (CDI) is increasing in both prevalence and severity. While the majority (56%) of reported cases are associated with a stay in a healthcare facility, the remaining (44%) cases, numbering 65.8 cases/1000 individuals, are considered community-associated CDI.11 Of these, it has been estimated that 65% of the community associated CDI occurred after the use of antibiotics.12 Manifestations of CDI range from mild to life-threatening sequelae. CDI can result in pseudomembranous colitis, toxic megacolon, colon perforations, sepsis, and, rarely, death.8
Clinical factors associated with increased risk of CDI include age older than 65 years, the presence of underlying disease, and recent courses of antibiotics.12 Dentists are estimated to prescribe 10% of outpatient antibiotics, so while they are not the sole source of these drugs in the community, they make a measurable contribution to it.3 There is some overlap among the antibiotics commonly prescribed by dentists and those reported to carry higher risk for CDI. Antibiotics associated with higher risk of CDI include clindamycin, the cephalosporins, and the fluoroquinolones,12 which are reported to account for 14%, 5%, and less than 1% of the antibiotics prescribed by dentists, respectively.3
Some clinicians prescribe probiotics during a course of antibiotics for the prevention of CDI. According to the Infectious Diseases Society of America (IDSA), there are insufficient data supporting the effectiveness of probiotics in preventing CDI, and the administration of probiotics for this purpose is therefore not recommended by the IDSA at this time.13