Impact of the microbiome on oral biopharmaceutics

The human microbiome is composed of the genomes of trillions of microbes inhabiting the human body: namely, bacteria, viruses, fungi and protozoa. Microbiome composition is also highly individual and sensitive to external factors, making microbiome-biopharmaceutical implications complex to predict. The effects of antimicrobials on the gastroenterol microbiome are well documented, with short courses of some oral antibiotics negatively impacting intestinal microbial diversity for several years after treatment cessation. Parenteral drugs have the propensity to be altered by gastrointestinal microbiota; their systemic circulation may lead them into contact with epithelial cells, or excretion in bile could cause them to bypass microbiota in the colon. Enzymatic degradation of drugs can result in altered bioavailability and/or exposure to toxic metabolites. The metabolic potential of the microbiome can also be harnessed for the targeted delivery of drugs, exemplified by the use of fermentable tablet coatings designed for colonic release.