Background:~The increasing prevalence of obesity and diabetes mellitus seems to reach epidemic proportions worldwide. In particular visceral obesity in combination with impaired glucose tolerance is associated with risk for progression of a broad spectrum of cardiometabolic diseases such as type 2 diabetes, hypertension, dyslipidemia, cardiovascular disease and non-alcoholic fatty liver disease (NAFLD). Thus, among patients undergoing bariatric surgery more than 95% have NAFLD, with nonalcoholic steatohepatitis (NASH) being present in 32-39 %.~Only bariatric surgery currently seems to attain long-term weight loss in morbidly obese patients. In addition, greater success in terms of improvement in obesity related comorbidities and reduction of overall-mortality can be achieved by surgical measures. Recent data indicate that Mini-Gastric Bypass (MGB) is an effective procedure for weight loss and reduction of comorbidities. Although weight loss is usually recommended as therapy for obesity with NAFLD and NASH, not all NAFLD patients benefit from surgical induced weight loss as indicated by increase in transaminase activity. An optimized micronutrient in combination with a probiotic supplementation could be a useful tool to prevent the transition from NAFLD to NASH.~Aim:~Therefore this study aims to elucidate the effect of a specific micronutrient-probiotic-combination on fatty liver and insulin resistance in obese patients after MGB surgery. Furthermore, this study aims to help optimizing the dietary food supplementation after MGB to reduce the progress of NAFLD/NASH and cardiometabolic diseases.~Methods:~A randomized double blind clinical trial of 12 week dietary intervention with a specific micronutrient-probiotic-combination will be conducted in obese patients with NAFLD after standardized MGB surgery. To this end, a total of 60 patients will be randomly assigned to a specific micronutrient-probiotic-combination or micronutrient-placebo-combination group. During the preoperative 4-week run-in phase, each patient receives a formula diet to improve protein and micronutrient supply. This should align the metabolic situation within the study group. At baseline and study end blood samples are taken for further analysis of metabolic, clinical and biochemical parameters. Anthropometric data (body height, body weight, and waist circumference) and bioelectrical impedance analysis are also collected at the beginning and after 8 and 12 weeks. Fecal samples will be collected prior to surgery and after 4, 8 and 12 weeks (concomitant variable). All patients will fill out validated food intake questionnaires and stool questionnaires (frequency and consistence) after 4, 8 and 12 weeks (concomitant variable).
Aim of this prospective randomized intervention study is to evaluate the effect of a dietary intervention with a specific micronutrient-probiotic-combination for 12 weeks on fatty liver and cardiometabolic status in obese, nonalcoholic fatty liver disease (NAFLD) patients after Mini-Gastric Bypass (MGB) surgery.