Group B Streptococcus (Streptococcus agalactiae, GBS) is a leading cause of invasive infections in neonates and adults. The adult gastrointestinal (GI) tract represents an understudied site of asympto...

The Centers for Disease Control and Prevention classifies Clostridioides difficile as an urgent threat to the nation’s health, as it causes 450,000 infections, 15,000 deaths, and 1 billion dollars in excess healthcare costs per year in the United States (1, 2). Most C. difficile infections (CDIs) occur in healthcare settings, where CDI is the most common cause of infectious diarrhea (3). Known and suspected risk factors for CDI include antibiotics, proton pump inhibitors, impaired immune function, advanced age, and diet, all of which are associated with dysbiotic gastrointestinal (GI) microbiomes (4–6). Though most CDIs are associated with antibiotic treatment, 22% of individuals with community-acquired CDI have no recent history of antibiotic use. Factors affecting persistent and recurrent CDIs remain poorly defined (7, 8). Despite the morbidity and mortality caused by C. difficile, up to 15% of healthy adults are asymptomatic carriers of toxigenic C. difficile (9), highlighting the gaps in our understanding of C. difficile.