Branched-chain/aromatic amino acids as integrated biomarker of type 2 diabetes mellitus: a systematic review and meta-analysis

Background:As type 2 diabetes mellitus(T2DM)biomarkers,branched-chain amino acids(BCAAs:valine,leucine and isoleucine)and aromatic amino acids(AAAs:phenylalanine,tryptophan and tyrosine)may be correlated with the occurrence and development of T2DM.However,there is still no consensus on the disperse and isolated biomarkers of T2DM.Purpose:To explore the correlation between amino acids and T2DM based on integrated biomarker approach revealed.Methods:PubMed,Web of Science and CNKI were selected to search the literature published until August 31,2019.The included studies described the association between BCAAs,AAAs and T2DM.Random effect model and fixed effect model were adopted in pooled analysis to determine mean difference and 95 percent confidence interval of metabolites.Integrated biomarker was constructed in form of concentration change ratios or risk ratio(RR),relative risk(HR)and odds ratio(OR)of BCAAs and AAAs to reflect the integrated change information of amino acids.Results:The selected 20 studies contained 14942 healthy individuals and 3615 T2DM patients.The levels of BCAAs,phenylalanine and tyrosine both in plasma and serum samples were increased among all T2DM patients compared with those of the healthy control subjects(P<0.00001).However,the mean difference of tryptophan concentration was not statistically significant(P=0.60).The concentration change ratios or HR/RR/OR of BCAAs and AAAs were connected to form integrated biomarker.Conclusion:The integrated biomarker including BCAAs and AAAs could reflect the basic characteristics of T2DM,which has the potential clinical value on comprehensive diagnosis of T2DM.

Gut microbiota: a potential target for insulin resistance and type 2 diabetes mellitus

Insulin resistance(IR)runs through the whole process of occurrence and development of type 2 diabetes mellitus.Gut microbiota is the largest micro-ecosystem in human body,which has an important influence on the metabolism of material and energy.Recent studies have shown that besides genetic and islet dysfunction,disorders of the gut microbiota induced by dietary imbalance may lead to IR,which influence health.Here,we reviewed the research status of the correlation between IR and gut microbiota,and summarized the relationship between IR and gut microbiota,metabolites of gut microbiota and IR,and possible mechanism of gut microbiota participating in IR,which provides theoretical basis and literature reference for the treatment of IR and type 2 diabetes mellitus by gut microbiota regulation.