[Surgical treatment of obesity from the nutritional point - opportunities and dangers].

Obesity is a civilization disease, which occurrence in the world population is gradually increasing. The basic causes of obesity include a sedentary lifestyle and energy-rich diet contributing to a positive energy balance. Methods of curing obesity contain the lifestyle modification, the pharmacological treatment and the surgical treatment. The bariatric surgery is a therapy that can be used among patients with BMI ≥40 or BMI ≥35 kg/m2 with comorbidities, e.g. hypertension, for whom previous treatment has been ineffective. The surgical treatment includes restrictive, limiting absorption and hybrid methods among them the most frequently performed sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). Surgical treatment affects the clinical course of many chronic diseases, e.g. diabetes mellitus type 2. Unfortunately, this method of treatment is related to complications and is associated with increased risk of many complications, nutritional deficiencies, as well as deterioration of mental health. The potential causes of psychiatric disorders following bariatric surgery include dysbiosis and brain - gut axis dysfunction. After surgery, a dysbiosis is noticed (a reduction of Bifidobacterium spp.) that may increase the risk of depressive disorders occurrence. For this reason, to effective obesity treatment, patients undergoing bariatric surgery should be covered by the longterm care of an interdisciplinary team.