Modulating the Human Gut Microbiome and Health Markers through Kombucha Consumption: A Controlled Clinical Study

Fermented foods are surging in popularity globally due to their links to metabolic health and the gut microbiome. However, direct clinical evidence for the health claims is lacking. Here, we describe an eight-week clinical trial that explored the effects of a kombucha supplement in healthy individuals consuming a Western diet, randomized into the kombucha ( n = 16) or control ( n = 8) group. We collected longitudinal stool and blood samples to profile the human microbiome and inflammation markers. Paired analysis between baseline and end of intervention time points within kombucha or control groups revealed increases in fasting insulin and in HOMA-IR in the kombucha group whereas reductions in HDL cholesterol were associated with the control group. Shotgun metagenomic analysis revealed the relative abundance of Weizmannia , a kombucha-associated probiotic to be overrepresented in consumers at the end of the intervention. Short-term kombucha intervention induced modest impacts on human gut microbiome composition and biochemical parameters.