Inclusion Criteria:  18 to 65 years of age Body mass index between 18.5 - 25.0 kg/m2  Exclusion Criteria  Estimated creatinine clearance < 50 mL/min Liver impairment (liver enzymes > 2 times upper limit) Antibiotics in the past 3 months History of gastrointestinal disease History of autoimmune disorder Chronic viral infection Smoker Alcohol intake (defined as having up to 1 drink per day for women and up to 2 drinks per day for men) Use of immune modulating medications Diabetes mellitus Any history or contraindication to the study medications Additional exclusion criteria will be based on the FDA approved prescribing information for selected drugs (i.e., contraindications)