Effects of Probiotics and Synbiotics on Obesity, Insulin Resistance Syndrome, Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease: A Review of Human Clinical Trials
*1 Department of Biochemistry & Molecular Biology I, School of Sciences, University of Granada, Granada 18071, Spain 2 Institute of Nutrition and Food Technology “José Mataix”, Biomedical Research Center, University of Granada, Armilla 18100, Spain 3 Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, Granada 18071, Spain 4 Instituto de Investigación Biosanitaria ibs, GRANADA, Complejo Hospitalario Universitario de Granada/Universidad de Granada, Granada 18014, Spain 5 CIBEROBN (Physiopathology of Obesity and Nutrition CB12/03/30038), Instituto de Salud Carlos III (ISCIII), Madrid 28029, Spain *
Int. J. Mol. Sci.2016, 17(6), 928; https://doi.org/10.3390/ijms17060928 Received: 16 April 2016 / Revised: 24 May 2016 / Accepted: 2 June 2016 / Published: 13 June 2016
The use of probiotics and synbiotics in the prevention and treatment of different disorders has dramatically increased over the last decade. Both probiotics and synbiotics are well known ingredients of functional foods and nutraceuticals and may provide beneficial health effects because they can influence the intestinal microbial ecology and immunity. The present study reviews the effects of probiotics and synbiotics on obesity, insulin resistance syndrome (IRS), type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD) in human randomized clinical trials. Select probiotics and synbiotics provided beneficial effects in patients with obesity, mainly affecting the body mass index and fat mass. Some probiotics had beneficial effects on IRS, decreasing the cell adhesion molecule-1 levels, and the synbiotics decreased the insulin resistance and plasma lipid levels. Moreover, select probiotics improved the carbohydrate metabolism, fasting blood glucose, insulin sensitivity and antioxidant status and also reduced metabolic stress in subjects with T2D. Some probiotics and synbiotics improved the liver and metabolic parameters in patients with NAFLD. The oral intake of probiotics and synbiotics as co-adjuvants for the prevention and treatment of obesity, IRS, T2D and NAFLD is partially supported by the data shown in the present review. However, further studies are required to understand the precise mechanism of how probiotics and synbiotics affect these metabolic disorders.
Keywords: probiotics; randomized clinical trial; obesity; insulin resistance; metabolic syndrome X; type 2 diabetes; non-alcoholic fatty liver disease; symbiotics