Design overview
This was a randomized crossover study with a control Western Diet (WD) compared to a Microbiome Enhancer Diet (MBD) where each participant served as their own control, thereby minimizing the impact of confoundersAfter an initial assessment period to establish outpatient dietary intake requirements (Days 1–9), all food was provided to participants, and they consumed the meals outpatient for 11 days (Days 10–20 and 39–49) and inpatient for 12 days (Days 21–32 and 50–61). Included was a minimum 14-day washout between diet periods. During the 14-day washout, participants returned home and were instructed to resume their usual diet and physical activity. The following additional restrictions were implemented prior to each study period: avoidance of alcohol during outpatient feeding periods, no caffeine up to 72 h before admission, no artificial sweeteners, and no strenuous physical activity 48 h prior to admission. All endpoint assessments were conducted while participants were housed in our metabolic ward