Study On The Effect And Mechanism Of High Nutrient-rich Foods Index Mixed Nuts On Regulating Glucose And Lipid Metabolism In Mice

Nuts and dried fruits are important healthy components of various dietary patterns such as the Mediterranean diet and the New Nordic diet and have also been emphasized in the dietary guidelines for Chinese residents.Consuming mixed nuts is a healthy dietary strategy proven to protect against chronic diseases associated with metabolic syndrome.However,the current formulations of mixed nuts are based on taste and stable supply,and there is a lack of formulation design based on nutritional research.This study combined the nutrient-rich foods(NRF)index model with linear programming(LP)technique to establish a new method for optimizing mixed nut formulations based on nutrient density.According to the determination results of the nutrient content of four kinds of nuts and three kinds of dried fruits,we adjusted the nutrient content indices of the nuts and dried fruits in the mixed nuts respectively.Combining nuts and dried fruits with 10 and 8 encouraging nutrients and 3 limiting nutrients,respectively,LP was used to calculate the mixed nut formula with the highest total NRF index and the lowest energy.And using the animal model of metabolic disorder induced by a high-fat diet to explore the role of high NRF index mixed nuts in regulating metabolic disorder in mice.Male C57BL/6J mice were fed a low-fat diet(LFD),a high-fat diet(HFD),HFD with a supplemented classical randomized controlled trial mixed nut formula(HFD + MN1),a domestic commercially available mixed nut formula(HFD + MN2),a high NRF index mixed nut formula(HFD + MN3),walnuts only(HFD + Wal)or ellagic acid(HFD + EA)(positive control).After 11 weeks of feeding,the plasma and liver-related metabolic indicators,gut microbiota,and metabolites of mice in each diet group were measured.Among the three mixed nut formulations,the total NRF index of MN3 was the highest at 4.15.The results of animal experiments showed that,compared with the HFD group,adding MN3 significantly reduced plasma total cholesterol(P < 0.05)and insulin resistance index(P < 0.05),while MN1 and MN2 had no statistical difference.In the oral glucose tolerance test of mice fed a high-fat diet,the addition of MN3 reduced the area under the blood glucose curve(P < 0.001)and maintained blood glucose homeostasis.MN3 treatment decreased lipid droplet rate and white adipocyte area in mice fed a high-fat diet(P < 0.001).MN3 treatment reduced plasma endotoxin lipopolysaccharide(LPS)and liver high sensitivity C-reactive protein levels(P < 0.01),and the effect was better than that of MN1 and MN2.MN3 treatment decreased the number of Kupffer cells in the liver(P < 0.001),the level of the membrane receptor CD14 of LPS(P < 0.05),and down-regulated the LPSmediated MAPK pathway in the liver(P < 0.01)and monocyte differentiation(P < 0.001).MN3 treatment up-regulated cholesterol metabolism in the ileum(P < 0.01)and increased fecal cholesterol and bile acid excretion.MN3 treatment increased the expression of colonic tight junction protein Occludin and ZO-1(P = 0.053,P = 0.058)and strengthened the mucosal barrier.16 S r RNA amplicon sequencing analysis showed that MN3 treatment increased the α-diversity of the cecal microbiota,but the difference was not statistically significant,and significantly changed the β-diversity(P < 0.05)and increased the abundance of the genus Lachnospiraceae＿NK4A136(P < 0.001)compared to the HFD group,while MN1 and MN2 were not statistically different.Non-targeted metabolomics results showed that MN3 treatment increased the contents of plasma metabolites docosahexaenoic acid,α-linolenic acid,sphingosine,and cinnamic acid(P < 0.05),and decreased the contents of arachidonic acid and methionine(P < 0.05),and promote the excretion of kynurenine,isoleucine,glycerophospholipids and glycosphingolipids(P <0.05).In conclusion,the NRF index model and LP technology can optimize the mixed nut formulation and obtain a mixed nut formulation with a high NRF index,which can play a role in regulating the disorders of glucose and lipid metabolism in mice on a high-fat diet,and the effect is better than the foreign classic mixed nut research formulation and the domestic commercially available mixed nut formulation.The mixed nuts with a high NRF index could reduce plasma total cholesterol,homeostatic model assessment of insulin resistance,plasma and liver pro-inflammatory cytokines,and LPS levels in mice on a highfat diet,possibly by inhibiting the hepatic MAPK pathway,activating ileum cholesterol metabolism,remodeling gut microbiota,strengthening the mucosal barrier,and activating tryptophan metabolism,α-linolenic acid,and sphingolipid metabolism.