Beta-Hydroxybutyrate Feasibility Treating IBD

Inclusion Criteria: * Age ≥18 years of age * Confirmed diagnosis of Crohn's disease * Active disease defined as either a fecal calprotectin \>250 µg/g or active disease on endoscopy within the prior 3 months * Starting a new therapy defined as a biologic (anti-TNF, anti-integrin, IL-12/23, or IL-23) or small molecule therapy (JAK inhibitor, S1P receptor modulator) * Willing to provide consent for participation. * Managed at UT Digestive Health Clinic. Exclusion Criteria: * Any current or recent (within 4 weeks) use of BHB supplement * Currently or recently (within 4 weeks) following a ketogenic diet * Currently or recently (within 4 weeks) following an intermittent fasting diet * Any recent antibiotic use (within 3 months) * Recent infection with C. difficile (within 6 months) * Current or recent (within 4 weeks) daily use of acid-suppressing therapy (proton pump inhibitor or H2 receptor blocker) * Current or recent use (within four weeks) of non-dietary probiotic supplements * Unwilling to provide signed consent