First, we conducted anxiety/depression screening for all patients visiting our study site for health checkup who were over 18 years old, had chronic GI symptoms over >3 months and had no suspected lesions of malignancy or acute inflammation on a current endoscopy. Anxiety/depression screening was done using the Hospital Anxiety and Depression Scale (HADS), which was originally designed for general hospital settings. The HADS includes seven questions assessing depression and seven assessing anxiety. Each question is answered on a scale of 0 to 3. The total scores for the depression and anxiety components are calculated, with each component score ranging from 0 to 21. A depression/anxiety component score of 8 or higher suggests possible depression/anxiety, respectively.
Then, those who had a component score of 8 or higher were invited to participate in the study. Patients who agreed to participate would receive an 8-week multispecies probiotic supplementation in addition to the medications prescribed by the clinic's doctor. The prescribed medications might include antibiotics (often for the treatment of Helicobacter pylori or small intestinal bacterial overgrowth), proton-pump inhibitors, or other medications for gastrointestinal conditions. Psychiatric drugs were not prescribed for our study patients.
The multispecies probiotic product contains eight bacterial strains including Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, Lactococcus lactis W19, and Lactococcus lactis W58. The product consists of over 2,5 x 109 CFU per gram with other excipients including corn starch, maltodextrins, potassium chloride, magnesium sulphate, manganese sulphate, inulin and plant-based proteins. Dosage form is the dry powder which be supplied as sachets. This product was manufactured in Netherlands by Winclove B.V Company and distributed in Vietnam by Dong Do Pharmacy Company. It has been approved by the Department of Food Safety, Vietnam's Ministry of Health for the use as a supplement in patients with symptoms of depression and/or anxiety (approval No. 38162/2017/ATTP-XNCB). Patients were instructed to use the multispecies probiotic product with their prescribed medications before meal. Patients would mix one sachet (2g of product) in 100mL of water, let stand for 1 minute, and stir well before use.
Patients were followed up after 1 and 2 months via phone interviews. The analytic population included only patients who had finished 2-month follow-up.
All participants were asked about their medical history, presenting GI symptoms (regurgitation, epigastric pain, heartburn, nausea, dysphagia, vomiting, changes in bowel habits, constipation, diarrhea, fecal incontinence) and constitutional symptoms, and quality of life assessed by the European Quality of Life scale EQ-5D-5L. On 1- and 2-month follow-up phone interviews, they were asked about current depression/anxiety status (HADS), quality of life (EQ-5D-5L), whether their presenting symptoms had changed (improved/not changed/worsened), and whether they had any new symptoms developed while using the multispecies probiotics product (yes/no questions). Patients were encouraged to share any complaints or issues with taking the prescribed medications and the multispecies probiotics product.
Demographic characteristics, clinical symptoms, medical history of the study participants are presented as numbers and percentages. The HADS and EQ-5D-5L scores are presented as the mean (standard deviation) or median (interquartile range). To compare between baseline, 1 month and 2 months, the Cochran's Q test was used to evaluate the changes in participants' symptoms and repeated-measures analysis of variance (RM-ANOVA) was used to compare the differences in the HADS and EQ-5D-5L scores. Mauchly's sphericity test was performed to check the assumption of sphericity, which is critical for RM-ANOVA, and Greenhouse-Geisser correction was applied if the assumption is violated. Differences were considered statistically significant when the p-value was < 0.05. All statistical analyses were performed using the Python programming language.
The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of the Dinh Tien Hoang Institute of Medicine under decision No. IRB-1908. All study participants were given all information about the study's objectives and process and provided informed consents to sign in before the study started. All study participants voluntarily participated in this study.