The purpose of the study is to evaluate the efficacy and safety of a synbiotic in a short-term course (4 weeks), including an extract of garcinia cambogia, probiotics and prebiotics in patients with MS Materials and methods. The pilot, observational, open-label, non-randomized prospective clinical trial included 20 patients with metabolic syndrome (13 males and 7 females, Me age 42 years). A biologically active food supplement (synbiotic) “LINNI SLIM” (PharmlandBIO, Republic of Belarus) was used, including an extract of garcinia cambogia (containing 60% hydroxycitric acid, 0.03 g/g), probiotic strains of the genus Bifidobacterium (B. bifidum, B. animalis ssp lactis, B. longum ssp longum) CFU/g) - 0.066x 109 CFU/g and Lactobacillus (L. Acidophilus, L. Plantarum, L. Rhamnosus, L. Casei, L. Crispatus, L. Reuteri, L. Gasseri) - 0,134 x 109 CFU/g; prebiotics (psyllium husk, microcrystalline cellulose, linseed fiber, inulin, fenugreek). The daily dose of garcinia cambogia is 0.3 g, dietary fiber is 5.16 g. The parameters of nutritional (including bioimpedance analysis) and metabolic status, safety (hepatotoxic effects) and tolerability (gastrointestinal symptoms, 2H-breath test with lactulose and glucose) were evaluated. Results. There was a significant decrease in serum concentrations of insulin (15.2 [9.7; 23.0] Vs 10.9 [6.6; 16.4] mcU/ml; p=0.002), triglycerides (2.1 [1.4; 2.3] Vs 1.2 [1.2; 1.9] mmol/l; p=0.002), values of the HOMA-IR index (3.77 [2.54; 6.08] Vs 2.50 [1.44; 3.65]; p=0.003) without deviation of serum biomarkers of liver damage. Good tolerability and safety of “LINNI SLIM” was established: the appearance of symptoms of dyspepsia, stool disorders requiring the abolition of dietary supplements, deviations in the results of the 2H-breath test were not registered. Conclusion. A 4-week course of using the “LINNI SLIM” synbiotic at a daily dose of 10 grams has a positive effect on the metabolic status of the body (reduction of insulin, triglycerides, HOMA-IR - insulin resistance index) with satisfactory safety parameters. The effectiveness and improvement of “metabolic health” allows the use of the “LINNI SLIM” synbiotic in the initial therapy for reducing (controlling) body weight in people suffering from metabolic syndrome on the background of obesity.