Daily Consumption of Kombucha Influences the Urinary and Plasma Metabolome in a Healthy Human Cohort

This study investigated a traditionally brewed, organically produced kombucha, which may contain antioxidants, polyphenols, and bioactive compounds resulting from fermentation. While kombucha is marketed as a functional drink, there is limited empirical research on the drink's functional benefits. Additionally, much kombucha sold in the global marketplace is produced using instant mixes, pasteurization, filtration, and top carbonation, creating a shelf-stable ambient product at significantly lower cost than fresh, refrigerated traditional Kombucha. An 8-week randomized, double-blinded, parallel trial investigated the effects of daily kombucha (330 mL) consumption on urinary and plasma metabolomics in healthy adults aged 18-71. Participants of mixed gender and ethnicity consumed either a trial canned kombucha or a placebo (flavored water). First Morning Void (FMV) urine and fasting venous blood samples were collected before and after the trial period. Urine samples were analyzed using Flow Infusion Electrospray Ionization Mass Spectrometry (FIE-MS), while plasma short-chain fatty acids (SCFAs) were quantified using Gas Chromatography-Flame Ionization Detection (GC-FID). The urinary metabolomic profile showed an increase in metabolites linked to kombucha-derived polyphenols and microbial fermentation, such as dihydroferulic acid and arabitol. Plasma analysis revealed a significant reduction in acetic acid and a marginal decrease in isoButyric acid after kombucha consumption. These findings highlight the complex interplay between fermented food consumption and human metabolism.