The impact of regular sauerkraut consumption on the human gut microbiota: a crossover intervention trialOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This randomized crossover trial tested whether daily sauerkraut changes the gut microbiome and short-chain fatty acids in healthy people. It compared fresh and pasteurized sauerkraut. Participants ate 100 grams daily for four weeks per type, separated by four-week washout phases, with each person serving as their own control. Stool microbiota was profiled by shotgun metagenomic sequencing, and fatty acids in stool and serum were measured by liquid chromatography-mass spectrometry.
Who was studied?
The trial ran in Freiburg, Germany, recruiting 87 healthy adults, of whom 84 completed all study phases. Participants were aged 21 to 69 years with body mass index between 18.1 and 30.8. Exclusions included smoking, diabetes, hypertension, gastrointestinal disease, and recent antibiotic use. Participants were randomized to start with either fresh or pasteurized sauerkraut, then crossed over to the other type.
What were the most important findings?
Neither sauerkraut type significantly changed overall microbial alpha or beta diversity, indicating resilient gut communities in healthy adults. Single species did shift. Fresh sauerkraut increased sauerkraut-derived lactic acid bacteria in stool, which disappeared after washout. Pasteurized sauerkraut mainly raised one commensal and modestly lowered another. Only pasteurized sauerkraut significantly increased serum acetic, propionic, and butyric acid. Fecal butyric acid fell after fresh sauerkraut consumption.
What are the greatest implications of this study?
The findings suggest a healthy adult gut microbiome resists short-term dietary change, with fermented food effects appearing mainly at the single-species level. Whole-community diversity stayed stable. The rise in serum short-chain fatty acids after pasteurized sauerkraut hints at a possible systemic metabolic benefit, consistent with a postbiotic effect. Because the pasteurized product's microbial content was uncertain and intake was self-managed, the mechanism and health relevance require further study.