(P42-37-26) Kimchi and Gut Health – Study Protocol for a Randomized Trial Assessing Effects on the Human Gut Microbiome and Metrics of GI and Cardiometabolic Function

Objectives: Kimchi is a common traditional Korean food growing in popularity. This study will assess how daily consumption of fermented cabbage-based kimchi affects indices of gut health compared to matching consumption of fresh Napa cabbage. The primary outcome is enrichment of fecal lactic acid bacteria (LAB) with secondary outcomes of gut barrier integrity and health, immune and cardiometabolic markers, and qualitative self-assessment of gut health.

Methods: This randomized controlled parallel-arm study will enroll 60 healthy adults (19-70 years) with BMI of 25-30 who do not regularly consume kimchi or similar fermented foods. A 2-week run-in period to exclude fermented foods, cabbage, and probiotics from the diet will precede a 3-week intervention, consisting of study-provided 60g kimchi or fresh cabbage portions to be eaten daily. Anthropometrics, blood and fecal samples will be taken at baseline and endpoint. Diet adherence and quality will be measured by ASA24. Gastrointestinal tolerance will be assessed using a validated Gastrointestinal Symptom Rating Scale (GSRS) and Digestive Quality of Life Questionnaire (DQLQ). Targeted 16SrRNA gene amplicon DNA sequencing and shotgun metagenomics will assess fecal LAB and microbiome composition. Biomarkers of gut integrity and health (fecal calprotectin, lipocalin and sIgA; plasma LBP, zonulin, and sCD14) will be measured via ELISA. Microbial metabolites (SCFA and secondary bile acids) will be measured via metabolomics, cardiometabolic (lipid panel) and immune (plasma IL-6, hsCRP) biomarkers will be measured by a clinical laboratory. Statistical analyses will include alpha and beta diversity, gut microbial differential abundance, and ANCOVA for gut health, clinical and metabolomic biomarkers.

Results: N/A

Conclusions: We expect to determine how consumption of kimchi and cabbage impact enrichment of microbial metabolites and microbiome composition and whether this is associated with enhanced protection of intestinal barrier function. Results will provide insights into how traditional fermented foods such as kimchi can affect gut microbiome, health biomarkers, and self-report of the digestive wellbeing of participants.

Funding Sources: USDA NIFA CA-D-NTR-6316-H, Korea Food Research Institute