Fermented soy supplementation improves indicators of quality of life: a randomized, placebo-controlled, double-blind trial in adults experiencing heartburn

OBJECTIVE: To determine if fermented soy supplementation relieves heartburn and improves gastrointestinal symptoms and quality of life, a randomized, double-blind parallel study was conducted with adults experiencing mild or moderate heartburn. Participants consumed up to 3, 1 g sachets of flavored, Lactobacillus delbrueckii fermented with soy flour (n = 23) or placebo (maltodextrin) (n = 27) sachets per heartburn incident as needed for 3 weeks. Symptom intensity at 5, 15, and 30 min post-administration was assessed using a Likert-like scale. The Gastrointestinal Symptoms Rating Scale (GSRS) and Gastro-esophageal Reflux Disease Quality of Life Questionnaire (GERD-QOL) were administered at baseline, post-intervention and following a 1-week washout. RESULTS: No significant differences between groups were seen for heartburn severity or frequency, GSRS syndromes, or GERD-QOL domains. However, individual QOL items related to inconvenience of taking medications, fear of eating, inability to concentrate at work, and disturbance of after-meal activities and rest improved with fermented soy compared to placebo. Frequency of heartburn, diarrhea, and bloating improved during washout vs. baseline for the fermented soy group compared to placebo. Lactobacillus delbrueckii fermented soy supplementation improved QOL indicators and may decrease heartburn occurrence over time vs. an acute effect; efficacy of daily intake and longer duration requires investigation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13104-020-05205-z) contains supplementary material, which is available to authorized users.