Metabolic Syndrome (MS) contributes to the development of cardiovascular diseases (CVD). According to the World Health Organization (WHO), CVDs are the leading causes of death in the world. According to epidemiological data from the Ministry of Health, these diseases account for 29.4% of all deaths recorded in Brazil annually. Kefir is obtained by fermenting milk with kefir grains and has been recommended as a therapeutic form for the treatment of various clinical conditions. The hypothesis of the present study is that the daily intake of fermented beverages with kefir grains may reduce the risk factors associated with MS, thus reducing the incidence of CVD. A clinical trial was conducted with 48 volunteers, who presented at least three criteria for the diagnosis of MS. The subjects were divided into two groups that received for eleven weeks fermented dairy drink with kefir (KG) grains or homemade curd (CG). Weight and height measurements were taken to calculate BMI. The body composition evaluation was performed by determining the percentage of body fat and waist circumference (WC). The measurements of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were taken. Blood samples were analyzed for fasting glycemia, glycated hemoglobin (HA1c), total cholesterol (TC), HDL cholesterol, triglycerides (Tg), C-reactive protein (CRP), aspartate aminotransferase (AST), Alanine Aminotransferase (ALT), Creatinophosphokinase (CPK), γ-Glutamyl Transferase (γ-GT), Urea Nitrogen, Urea and Creatinine. The level of non-HDL cholesterol (n-HDL) was determined by calculation. The Framingham score was used to assess the risk of developing cardiovascular events over the next ten years. Eleven weeks into the experiment, all measurements of body evaluation, SBP and DBP and biochemical analysis of blood were reevaluated.

This is a randomized, double-blind clinical trial with stealth allocation through an automated randomization system Random Allocation Software version 1.0, May 2004. The randomization codes were the responsibility of the professional supervisor of the Laboratory of Technique and Dietetics of the University Vila Velha - UVV / ES. The same professional was responsible for the identification of bottled beverages intended for volunteers. Double blind refers to the blinding of patients, researcher, data collectors and outcome assessors. The kefir group (KG) received orally probiotic milk fermented with kefir grains and the control group (CG) received curds. The follow-up of the clinical trial is classified as long-term as it lasted for eleven weeks. The subjects of the research were recruited in an university teaching institution. After recruitment, confirmation of the presence of MS parameters was performed through anthropometric analyzes, blood pressure measurement and biochemical parameters, following the NCEP-ATP-III criteria. The subjects were then randomized into two groups, the control (CG) and kefir (KG). After the 11-week period all analyzes performed before the randomization process were repeated. During the study the drugs for the reduction of serum cholesterol, arterial hypertension and any other medication of continuous use had their use maintained. The inclusion criteria were age above 18 years and having had alteration of the components of MS. Pregnant and lactating women were excluded from the study, those who used drugs for dyslipidemias that interfered with intestinal metabolism such as ezetimibe and anion exchange resin, hormones of any kind, medicines for weight loss and the use of antioxidant supplements such as vitamin C or ω-3. The present work was submitted and approved by the Ethics Committee in Research with Human Subjects of the University Vila Velha - UVV, under number 1,025,083. All the volunteers signed the free and informed consent form, agreeing to participate in the research. The sample was calculated to detect a 12% reduction in the levels of ultra-sensitive C-reactive protein (CRP), considering a standard deviation of 15% a 2-tailed of 0.5 and power of 80%. The products were distributed to the volunteers in the workplace during office hours, in the morning, Monday to Friday. The routine was followed daily, totaling eleven weeks of experiment. The anthropometric measurements were individually assessed at the UVV Nutrition Clinic before the beginning of the trial and were repeated at the end of the study. In order to measure body weight, the RAMUZA DP-300 digital platform scale was used with a maximum capacity of 200 kg and a precision of 100 g. The measurements were performed with light clothing and with barefoot volunteers. The stature was measured using the CHORDER HM 210D digital vertical anthropometry, maximum measurement of 210 cm and precision of 1mm, with barefoot individuals. For the calculation and classification of the body mass index (BMI), the cuts proposed by the WHO were adopted. The waist circumference (WC) was obtained by means of a millimeter and inelastic measuring tape. The cut-off points for risk assessment associated with metabolic complications of obesity were proposed according to WHO and SIMÃO et al. (2013). Body composition was analyzed by electrical bioimpedance (MaltronBody Fat Analyzer BF 906), as described by Lukaski et al. (1985). The percentage of lean mass and body fat was evaluated. During the experiment the food selection was at the discretion of the volunteer, following the composition and distribution of the meals they usually consume. The blood pressure measurement (SBP and DBP) was performed according to the protocol of the Sixth Brazilian Hypertension Guideline, using the average between two measurements performed using HEM-705CPINT automatic device, Omron, OmronHealth Care, INC., Illinois-USA. For biochemical analysis, fasting blood samples were collected by traditional venipuncture to evaluate the biochemical parameters of fasting glycemia, glycated hemoglobin (HA1c), total cholesterol (TC), high density lipoprotein (HDLc), triglycerides (Tg) (C-reactive protein), C-reactive protein (CRP), low-oxidized lipoprotein (LDLox), Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Creatinophosphokinase (CPK), γ-Glutamyl Transferase (γ-GT), Urea Nitrogen, Creatinine. The samples were sent to the Tommasi Clinical Analysis Laboratory - Vila Velha - ES, for further analysis. Low Density Lipoprotein (LDLc) and Non-HDLc Cholesterol were calculated from the biochemical analysis of the blood. To identify the relative and absolute risk of each volunteer from the research for the development of coronary disease in the next decade of life, it was applied the Framingham score for the risk of coronary heart disease. All data from anthropometry, food intake, biochemical analysis of blood, SBP and DBP, and Framinghan score were collected before and after the period of consumption of curd or kefir products. The data was compiled in spreadsheet elaborated in Microsoft Excel and were expressed as the average plus or minus standard deviation (S.D.). The database was analyzed using the statistical program SPSS 11.5 (Statiscal Package Social Science version 11.5). Simple relative frequencies were performed for qualitative variables within each group. For the quantitative data, descriptive statistics were performed and the differences were determined using the paired Student's T test (in the same group) and unpaired (between the groups) for a 95% confidence interval. The difference between means will be considered when p <0.05.

Inclusion Criteria:

• Age above 18 years, and;
• The presence of at least three of the five components of the metabolic syndrome.

Exclusion Criteria:

• Pregnant and lactating women;
• Subjects under the use of drugs for dyslipidemias that interfere with intestinal metabolism such as ezetimibe and anion exchange resin;
• Subjects under use of any kind of hormones;
• Subjects under the use of drugs for weight loss;
• Subjects under the use of antioxidant supplements such as vitamin C or ω-3.

Both Kefir and curd had been prepared to have the same consistency, color and flavor. Therefore, participants did not know if they were actually receiving kefir or curd. The care provider was a nutritionist that did not from each group the participants came from. There was two major investigators. The investigator responsible for the analysis of the data was also blind to the experimental groups, and he was also the outcome assessor.