Synbiotic Supplementation as a Part of Dietary Modification in Multiple Sclerosis

A total of 38 participants (18 in the intervention group and 20 in the control group) participated in the study among 92 female volunteers between the ages of 19-64 who were followed with a diagnosis of RRMS in the MS outpatient clinic of Bakırköy Prof. Dr. Mazhar Osman Training and Research Hospital.

The study was designed as a single-blind randomized clinical trial. During the first 6 weeks, all participants received medical nutrition Therapy (MNT) that adhered to the principles of the Mediterranean Diet. Following this period, participants were allocated into two groups based on a randomization table. During the next 6 weeks, the control group was given a placebo, while the intervention group received synbiotic supplementation (2 tablets a day) in addition to MNT. Evaluations were conducted at the beginning of the study (W1), at the end of 6th week (W6) and 12th week (W12). These assessments included three-day dietary intake records and the scores of the Healthy Eating Index (HEI-2015) derived from these records, 24-hour physical activity records, anthropometric measurements (body weight, height, waist circumference, hip circumference, mid upper arm circumference and triceps skinfold thickness), hand grip strength tests, biochemical markers (plasma fasting glucose, insulin, total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, liver enzymes (Alanine aminotransferase, Aspartate aminotransferase), albumin, creatinine, C-Reactive Protein, hemoglobin and hematocrit), BDI, MEDAS, MSQoL-54, and EDSS scores. Mid-arm muscle circumference and arm muscle area were calculated by using triceps skinfold thickness and mid upper arm circumference measurements. World Health Organization cut-off values were used to evaluate BMI and waist/hip ratio.

Synbiotic and placebo tablets administered for 6 weeks alongside MNT, were specially prepared for this study in line with the Turkish Food Codex Supplementary Foods Regulation. The synbiotic product contained Lactobacillus plantarum, Streptococcus thermophilus, Bifidobacterium lactis, Lactobacillus acidophilus, Bifidobacterium longum Enterococcus faecium, fructo-oligosaccharide, microcrystalline cellulose, corn starch, vitamin C, sweetener (xylitol and isomalt), milk flavor, anti-caking agent (hydroxypropyl methylcellulose), vanilla flavoring, anti-caking agent (magnesium salts of fatty acids). The placebo product contained only vitamin C and starch, which are considered safe for use in individuals with MS.

The synbiotic and placebo products were labeled in Turkish, following the GMP guidelines. A blinding procedure was applied to the participants.

Compliance with MNT and the product (symbiotic or placebo) use was monitored throughout the study by the research dietitian.

The data were analyzed using SPSS 22.0 and MS Excel programs. Distributions were assessed based on skewness values. For two-sample comparisons, the Paired Sample t-test, Independent Sample t-test, Mann- Whitney U test, and Wilcoxon Signed Ranks test were utilized. In triple comparisons, One-way ANOVA, repeated measures ANOVA, Friedman's test, Kruskal-Wallis H test, two-way ANOVA, and two-way ANOVA for repeated measures were utilized. Levene's test was applied to evaluate homogeneity of variance. In post-hoc analyses, Bonferroni correction, Games-Howell Dunn's test, Dunnett's test, and classical paired comparison tests were conducted. For comparing categorical data, Pearson chi-square, Fisher Exact test, and Likelihood Ratio tests were implemented. Interpretations were made at a 95% confidence level.

The "permutation method" was used for randomization. The block size was selected as an even number, and the number of groups and probabilities were equalized in each block. Random numbers were generated using Microsoft Excel to select the blocks, and a randomization table was created.

The sample selection required for the study was made by evaluating the current EDSS scores using the G-power 3.1.9.2 program, using alpha=0.05 and an effect size of 0.117 for the F test. A power of 1-beta=0.99 was obtained for 3 samples from 38 individuals (114 samples in total).

The study was ethically reviewed and approved by the Clinical Research Ethics Committee of Bakırköy Dr. Sadi Konuk Training and Research Hospital, Ministry of Health of the Republic of Turkey (decision no. 2020-25-01) and the Turkish Medicines and Medical Devices Agency, Ministry of Health of the Republic of Turkey (decision dated December 26, 2021, protocol code 18-AKD-153).