Background There is insufficient evidence for the ability of vitamin K2 to improve type 2 diabetes mellitus symptoms by regulating gut microbial composition. Herein, we aimed to demonstrate the key role of the gut microbiota in the improvement of impaired glycemic homeostasis and insulin sensitivity by vitamin K2 intervention. Methods We first performed a 6-month RCT on 60 T2DM participants with or without MK-7 (a natural form of vitamin K2) intervention. In addition, we conducted a transplantation of the MK-7-regulated microbiota in diet-induced obesity mice for 4 weeks. 16S rRNA sequencing, fecal metabolomics, and transcriptomics in both study phases were used to clarify the potential mechanism. Results After MK-7 intervention, we observed notable 13.4%, 28.3%, and 7.4% reductions in fasting serum glucose (P = 0.048), insulin (P = 0.005), and HbA1c levels (P = 0.019) in type 2 diabetes participants and significant glucose tolerance improvement in diet-induced obesity mice (P = 0.005). Moreover, increased concentrations of secondary bile acids (lithocholic and taurodeoxycholic acid) and short-chain fatty acids (acetic acid, butyric acid, and valeric acid) were found in human and mouse feces accompanied by an increased abundance of the genera that are responsible for the biosynthesis of these metabolites. Finally, we found that 4 weeks of fecal microbiota transplantation significantly improved glucose tolerance in diet-induced obesity mice by activating colon bile acid receptors, improving host immune-inflammatory responses, and increasing circulating GLP-1 concentrations. Conclusions Our gut-derived findings provide evidence for a regulatory role of vitamin K2 on glycemic homeostasis, which may further facilitate the clinical implementation of vitamin K2 intervention for diabetes management. Trial registration The study was registered at https://www.chictr.org.cn (ChiCTR1800019663).

To clarify the effects of dietary inflammatory and pro-oxidative potential, we investigated the impact of the Dietary Inflammation Index (DII) and the Dietary Oxidative Balance Score (DOBS) on all-cause and disease-specific mortality. For DII and DOBS, 17,550 and 24,527 participants were included. Twenty-six and seventeen dietary factors were selected for scoring. Cox proportional hazards regression models were used. DII and DOBS were significantly associated with all-cause, CVD, and cancer mortality in this nationally representative sample of American adults. Compared with the lowest DII, the multivariable-adjusted hazard ratios (95% CI) of all-cause, CVD, and cancer mortality for the highest were 1.49 (1.23–1.80), 1.58 (1.08–2.33), and 1.56 (1.07–2.25). The highest quartile of DOBS was associated with the risk of all-cause death (HR 0.71, 95% CI 0.59–0.86). Pro-inflammatory and pro-oxidative diets were associated with increased risk for all-cause (HR 1.59, 95% CI 1.28–1.97), and CVD (HR 2.29, 95% CI 1.33–3.94) death compared to anti-inflammatory and antioxidant diets. Similar results were observed among the stratification analyses. Inflammation-reducing and oxidative-balancing diets are linked to lower all-cause and CVD mortality. Diets impact health by regulating inflammation and oxidative stress.

Background Diabetic peripheral neuropathy (DPN) is a major complication of diabetes. This study aimed to investigate the therapeutic effects and molecular mechanisms of Compound Qiying Granules (CQYG) for DPN. Methods Rats and RSC96 cells of DPN models were established to evaluate the therapeutic effects of CQYG. Then the morphology and apoptotic changes of sciatic nerves were detected. Further, tandem mass tag based quantitative proteomics technology was used to identify differentially expressed proteins (DEPs) and the underlying molecular mechanisms. Protein expression of key signaling pathways was also detected. Results CQYG treatment significantly improved blood glucose and oxidative stress levels, and further reduced nerve fiber myelination lesions, denervation, and apoptosis in DPN rats. Further, 2176 DEPs were found in CQYG treated DPN rats. Enrichment analysis showed that protein processing in the endoplasmic reticulum (ER), and apoptosis were all inhibited after CQYG treatment. Next, CQYG treatment reduced inflammatory factor expression, mitochondrial damage, and apoptosis in RSC96 cells which induced by high glucose. Transmission electron microscopy results found that CQYG treatment improved the morphology of nerve myelin, mitochondria, and ER. CQYG treatment decreased ER stress and apoptosis pathway proteins that were highly expressed in DPN models. In addition, we also predicted the potential targets of CQYG in DEPs. Conclusions CQYG exerts neuroprotective effects in experimental diabetic neuropathy through anti-ER stress and anti-apoptosis.

Background Diabetic peripheral neuropathy (DPN) is a major complication of diabetes. This study aimed to investigate the therapeutic effects and molecular mechanisms of Compound Qiying Granules (CQYG) for DPN. Methods Rats and RSC96 cells of DPN models were established to evaluate the therapeutic effects of CQYG. Then the morphology and apoptotic changes of sciatic nerves were detected. Further, tandem mass tag based quantitative proteomics technology was used to identify differentially expressed proteins (DEPs) and the underlying molecular mechanisms. Protein expression of key signaling pathways was also detected. Results CQYG treatment significantly improved blood glucose and oxidative stress levels, and further reduced nerve fiber myelination lesions, denervation, and apoptosis in DPN rats. Further, 2176 DEPs were found in CQYG treated DPN rats. Enrichment analysis showed that protein processing in the endoplasmic reticulum (ER), and apoptosis were all inhibited after CQYG treatment. Next, CQYG treatment reduced inflammatory factor expression, mitochondrial damage, and apoptosis in RSC96 cells which induced by high glucose. Transmission electron microscopy results found that CQYG treatment improved the morphology of nerve myelin, mitochondria, and ER. CQYG treatment decreased ER stress and apoptosis pathway proteins that were highly expressed in DPN models. In addition, we also predicted the potential targets of CQYG in DEPs. Conclusions CQYG exerts neuroprotective effects in experimental diabetic neuropathy through anti-ER stress and anti-apoptosis.