The effect of probiotics derived metabolites on glucose uptake in skeletal muscle cells

Diabetes mellitus (DM) is a complex metabolic disease which often accompany with many complications. DM is caused by insufficient insulin secretion or resistance to insulin action on glucose uptake in peripheral tissues. It is estimated that about 90% of DM patients are type II diabetes worldwide and they are caused mainly by insulin resistance. Therefore, how to improve insulin resistance is considered to be one of the most important strategies for treating diabetes. Recently, many reserches have found that the changes in gut microbiota can influence the development of obesity, insulin resistance, and diabetes. Many reports have also indicated that the metabolites derived by gut microbiota may play key role in these functions. In this study, we first chose the palmitic acid -induced insulin resistance in L6 myotubes as the test platform to select effective probiotics metabolites. The results showed that conjugated linoleic acid (CLA), spermidine (SPD) and butyric acid (BTY) were effective metabolites which could increase glucose uptake activity of L6 cells, and the strains that had capacity to produce these selected metabolites were also found. In addition, precursors such as linoleic acid and L-arginine were added to increase the contents of these metabolites. Finally, we used three different probiotics strains to ferment soybean flour to obtain these desired metabolites. We found that the glucose uptake activity of L6 cells treated with the fermented soybean flour extracts was significantly increased to 1.67 times as compared to the control group (the DMSO treated group) and even superior to the results of the positive control group (the insulin treated group). Consequently, the application of the fermented metabolite mixtures might have a potential to improve insulin resistance disorder in the future.