Antimicrobial therapy has the potential to cause unintended adverse effects by promoting antibiotic-resistant bacteria. Therefore, as new antibiotics are developed there is a need to understand their potential to disrupt the indigenous microbiota of the colon and promote colonization by pathogens. Tebipenem pivoxil (Teb-piv), the first oral carbapenem, has potent in vitro activity against Enterobacterales pathogens, but requires combination with an appropriate β-lactamase inhibitor to achieve activity against Klebsiella pneumoniae carbapenemase and metallo-β-lactamase (MBL)-producing carbapenem-resistant Enterobacterales