Functional dyspepsia (FD) is a frequent functional gastrointestinal disorder characterized by bothersome postprandial fullness, early satiety, epigastric pain, or burning, in the absence of any structural or metabolic cause. It significantly impairs quality of life and has limited therapeutic options, as conventional treatments such as proton pump inhibitors often show modest efficacy and may cause side effects with long-term use. The gut and duodenal microbiota may play a role in FD. Spore-forming probiotics such as Bacillus coagulans MY01 and Bacillus subtilis MY02 have shown beneficial effects on FD symptoms in a randomized controlled trial. Ginger (Zingiber officinale) has a long history of traditional use as a gastroprotective agent and is supported by clinical and non-clinical data for improving gastric motility and related symptoms. This study (SUBTILE, STO-253) is a prospective, interventional, multicenter trial conducted in France. It will evaluate the effect of a dietary supplement containing Bacillus coagulans MY01, Bacillus subtilis MY02, and ginger extract (50 mg, 20% gingerols) on FD symptoms and quality of life. A total of 198 adult patients diagnosed with FD according to Rome IV criteria and with a normal upper endoscopy will be recruited in primary care and gastroenterology practices. Participants will take one capsule of the study product daily for 8 weeks. The primary outcome is the change in the Patient Assessment of Gastrointestinal Symptom Severity (PAGI-SYM) total score between baseline and Week 8. Secondary outcomes include changes in quality of life (PAGI-QoL), treatment adherence, use of concomitant medications, evolution of lower gastrointestinal symptoms, patient and physician global impressions of change (PGI-C, CGI-I), and satisfaction (Likert scales). An exploratory objective will assess psychological impact using the Hospital Anxiety and Depression Scale (HADS). The study includes two site visits (baseline and end of study) and one telephone follow-up at Day 28. Safety and tolerability will be monitored through active reporting of adverse events. The trial aims to provide new evidence on the role of probiotics combined with ginger extract as a non-pharmacological strategy to improve digestive comfort and quality of life in patients with functional dyspepsia.
Functional dyspepsia (FD) is one of the most common disorders of gut-brain interaction (DGBI), with an estimated prevalence of 7-8% in the general population. It is defined by Rome IV criteria as bothersome postprandial fullness, early satiety, epigastric pain, or burning, persisting for at least 3 months with onset at least 6 months before diagnosis, and without evidence of structural disease. FD is associated with impaired quality of life, psychological distress, and significant health care utilization. Current treatment options, including proton pump inhibitors and prokinetics, have limited efficacy and potential adverse effects when used long term. Emerging evidence suggests a role of the gastrointestinal microbiota in FD pathophysiology. Alterations in duodenal microbiota, as well as small intestinal bacterial overgrowth (SIBO) promoted by chronic PPI use, have been reported. Probiotics may reduce dyspeptic symptoms, improve gut barrier function, modulate gastric motility, and exert anti-inflammatory effects. A randomized controlled trial showed that Bacillus coagulans MY01 and Bacillus subtilis MY02 improved FD symptoms compared to placebo, with good safety and tolerability. In parallel, ginger (Zingiber officinale) has a well-documented gastroprotective effect, supported by both preclinical and clinical data, and has been shown to enhance gastric emptying and reduce upper gastrointestinal discomfort. The present study (SUBTILE, STO-253) is a prospective, multicenter, interventional trial conducted in France, categorized as RIPH2 (research involving human participants at minimal risks and constraints) under French regulations. The study will evaluate the effect of a dietary supplement combining Bacillus coagulans MY01, Bacillus subtilis MY02, and ginger extract (50 mg, 20% gingerols), marketed in France since January 2025 as Symbiosys® Stomalex. A total of 198 adult patients with FD (Rome IV criteria, normal endoscopy) will be recruited in primary care and gastroenterology practices. After providing informed consent, eligible participants will receive one capsule per day for 8 weeks. The study involves two in-person visits (baseline and Week 8) and one telephone follow-up at Day 28. The primary endpoint is the change in total PAGI-SYM score from baseline to Week 8. Secondary endpoints include changes in PAGI-QoL scores, treatment adherence, use of concomitant therapies, evolution of lower gastrointestinal symptoms, global impressions of change from both patients (PGI-C) and physicians (CGI-I), and satisfaction ratings. An exploratory endpoint evaluates psychological impact using the Hospital Anxiety and Depression Scale (HADS). Safety endpoints include frequency and severity of adverse events. This study will provide additional clinical evidence on the potential role of spore-forming probiotics combined with ginger extract as a complementary non-pharmacological approach to improve digestive symptoms and quality of life in patients with functional dyspepsia.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
198
One oral capsule per day for 8 weeks. Each capsule contains Bacillus coagulans MY01, Bacillus subtilis MY02, and ginger root extract (50 mg, titrated to 20% gingerols).
Gerard DASSA
Istres, France
RECRUITINGChange in PAGI-SYM total score from baseline to Week 8
The Patient Assessment of Gastrointestinal Symptom Severity Index (PAGI-SYM) is a validated questionnaire assessing severity of upper gastrointestinal symptoms. Total score ranges from 0 (none) to 5 (very severe). A decrease indicates symptom improvement.
Time frame: Baseline (Day 0) and Week 8 (Day 56 ± 3 days)
Change in Patient Assessment of Upper Gastrointestinal Symptom Severity Index (PAGI-SYM) Scores During Follow-up
The PAGI-SYM (Patient Assessment of Upper Gastrointestinal Symptom Severity Index) is a validated patient-reported questionnaire assessing upper gastrointestinal symptoms. It includes 20 items scored on a 6-point Likert scale from 0 to 5 (0 = none, 5 = very severe). Subscale scores and the total score are calculated as the mean of completed items. Higher scores indicate worse symptom severity. A decrease from baseline reflects clinical improvement.
Time frame: Baseline, Weeks 2, 4, 6, and 8
Change in Patient Assessment of Upper Gastrointestinal Quality of Life (PAGI-QoL) Total Score
The PAGI-QoL (Patient Assessment of Upper Gastrointestinal Quality of Life) is a validated patient-reported questionnaire measuring quality of life in functional dyspepsia. It includes 30 items, each scored on a 6-point Likert scale from 0 to 5. Subscale and total scores are calculated as the mean of completed items. Total score range: 0 (lowest quality of life) to 5 (highest quality of life). Higher scores reflect better quality of life.
Time frame: Baseline, Week 4, and Week 8
Patient adherence to study product assessed by patient diary
Adherence will be assessed using a patient diary in which participants record daily intake of the study product. Adherence will be expressed as the proportion of days with documented capsule intake relative to the total number of days.
Time frame: Week 4, and Week 8
Use of concomitant medications for dyspeptic symptoms
Proportion of patients using additional treatments for FD.
Time frame: 2 months prior to inclusion and during study period (8 weeks)
Evolution of lower gastrointestinal symptoms
Change in presence/absence of symptoms compared to baseline.
Time frame: Baseline and Week 8
Patient's Global Impression of Change (PGI-C)
The PGI-C (Patient's Global Impression of Change) is a self-reported 7-point Likert scale evaluating the patient's perception of change in health status since baseline. The scale ranges from 1 to 7, where 1 = very much improved, 2 = much improved, 3 = minimally improved, 4 = no change, 5 = minimally worse, 6 = much worse, and 7 = very much worse. Lower scores (1-3) indicate clinical improvement, 4 indicates stability, and higher scores (5-7) indicate worsening.
Time frame: Week 8
Clinical Global Impression of Improvement (CGI-I)
The CGI-I (Clinical Global Impression of Improvement) is a physician-rated 7-point Likert scale assessing global improvement of the patient's condition compared with baseline. The scale ranges from 1 to 7, where 1 = very much improved, 2 = much improved, 3 = minimally improved, 4 = no change, 5 = minimally worse, 6 = much worse, and 7 = very much worse. Lower scores (1-3) indicate improvement, 4 indicates stability, and higher scores (5-7) indicate worsening.
Time frame: Week 8
Patient satisfaction with study product
5-point Likert scale (1 = not at all satisfied; 5 = very satisfied).
Time frame: Week 8
Physician satisfaction with study product
5-point Likert scale (1 = not at all satisfied; 5 = very satisfied).
Time frame: Week 8
Exploratory: Change in Hospital Anxiety and Depression Scale (HADS) score
Evaluates impact on anxiety and depression. Total score ranges 0-21 per domain; higher scores indicate greater severity.
Time frame: Baseline and Week 8
Safety and tolerability (Adverse Events)
Number, severity, and relationship of adverse events (AE) and serious adverse events (SAE).
Time frame: From consent signature to Week 8 (end of study)
Patient adherence to study product assessed by capsule count
Adherence will be assessed by counting the number of remaining capsules at study visits. Adherence will be expressed as the proportion of capsules taken relative to the number of capsules dispensed.
Time frame: Week 4 and Week 8
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