A type of bacteria called Weissella, which is not normally found in the gut, was detected more often in older women who ate fermented plant foods every day, but not in those who rarely ate them, indicating it may come from food rather than living in the gut permanently.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether Weissella detection in human feces is consistently linked to daily consumption of plant-based fermented foods across diverse populations and fermentation types.
A systematic review and meta-analysis of all published studies reporting Weissella abundance in human feces, comparing individuals consuming daily plant-based fermented foods (e.g., soy, rice, mushroom) versus those consuming none, with standardized sequencing methods and dietary assessment.
Whether daily ingestion of Weissella-containing fermented foods leads to transient detection of Weissella in feces of postmenopausal omnivores within 7 days.
A double-blind RCT of 50 postmenopausal omnivorous women (60–75 years) randomized to consume 100g/day of Weissella-rich fermented mushroom (FVG-3) or a heat-treated placebo for 14 days, with daily fecal sampling and qPCR for Weissella to detect presence and duration.
Whether daily fermented food intake predicts Weissella detection in feces over time in postmenopausal women.
A prospective cohort study following 200 postmenopausal women for 1 year, collecting monthly fecal samples and daily fermented food logs, using qPCR to track Weissella presence and correlating it with frequency and type of fermented food intake.
Whether postmenopausal women with detectable Weissella in feces are more likely to consume daily plant-based fermented foods than those without.
A case-control study comparing 80 women with detectable Weissella in feces (via qPCR) to 80 without, matched for age and BMI, and assessing daily fermented food intake over the past 5 years via validated questionnaires.
Whether Weissella detection in feces correlates with daily consumption of plant-based fermented foods in postmenopausal women.
A cross-sectional analysis of 150 postmenopausal women measuring Weissella abundance via 16S sequencing and daily fermented food intake via 7-day food diary, comparing prevalence between daily consumers and rare consumers.