Sodium salicylate rewires hepatic metabolic pathways in obesity and attenuates IL-1β secretion from adipose tissue - implications for obesity-impaired reverse cholesterol transport

Mechanism of liver x receptor alpha in intestine, liver and adipose tissues in metabolic associated fatty liver disease

Metabolism associated fatty liver disease (MAFLD) has emerged as a growing global health challenge with limited effective treatments. Research on nuclear receptors offers promising new therapeutic avenues for MAFLD. The liver X receptor (LXR) has gained attention for its roles in tumors and metabolic and inflammatory diseases; However, its effects on MAFLD treatment remain a subject of debate. This review explores the therapeutic role of LXRα in MAFLD, focusing on its functions in the intestine, hepatic and adipose tissue, and summarizes recent advancements in LXRα ligands over the past five years. In the intestine, LXRα activation enhances the efflux of non-biliary cholesterol and reduces inflammation in the gut-liver axis by regulating intestinal high-density lipoprotein synthesis and its interaction with lipopolysaccharide. In the liver, LXRα activation facilitates cholesterol transport, influences hepatic lipid synthesis, and exerts anti-inflammatory effects. In adipose tissue, LXRα helps delay MAFLD progression by managing lipid autophagy and insulin resistance. Ligands that modulate LXRα transcriptional activity show considerable promise for MAFLD treatment.

The effects of saturated fat intake from dairy on CVD markers: the role of food matrices

CVD is the leading cause of death worldwide, and is commonly associated with modifiable risk factors. Most studies to date examining link between food intake and risk of CVD, have focused on modulation of plasma cholesterol concentrations (total cholesterol (TC), LDL-C). However, recent studies suggest LDL particle size is a more sensitive risk marker for CVD with smaller, dense LDL particles reported as more atherogenic than larger, more buoyant LDL. Although dietary guidelines recommend SFA intake of < 10 % of total energy, this does not consider food source, with recent evidence suggesting differing, sometimes beneficial, lipid responses following consumption of SFA from dairy compared to other food sources. This may be from differences in the physical food matrices, the nutrient content of the foods, and/or how these components interact with each other, described as a 'dairy matrix effect'. Dietary fat not only raises LDL-C, but also HDL cholesterol (HDL-C), associated with reduced CVD risk. HDL particles are complex emulsions of lipids, proteins and microRNAs that exhibit atheroprotective properties. In addition, HDL particles exhibit a very heterogeneous proteomic composition, dependent on a person's disease state - with a more pro-inflammatory proteome evident in patients with established CVD. This review will discuss the evidence to date on the importance of the food matrix in modulating response to dietary SFA and impact on CVD risk factors. A focus on potential biomarker properties of lipoprotein particles beyond cholesterol and current use of such biomarkers in human nutrition research will be considered.

Biomarkers of Hepatic Dysfunction and Cardiovascular Risk

PURPOSE OF REVIEW

The objective of this manuscript is to examine the current literature on non-alcoholic fatty liver disease (NAFLD) biomarkers and their correlation with cardiovascular disease (CVD) outcomes and cardiovascular risk scores.

RECENT FINDINGS

There has been a growing appreciation for an independent link between NAFLD and CVD, culminating in a scientific statement by the American Heart Association in 2022. More recently, studies have begun to identify biomarkers of the three NAFLD phases as potent predictors of cardiovascular risk. Despite the body of evidence supporting a connection between hepatic biomarkers and CVD, more research is certainly needed, as some studies find no significant relationship. If this relationship continues to be robust and readily reproducible, NAFLD and its biomarkers may have an exciting role in the future of cardiovascular risk prediction, possibly as risk-enhancing factors or as components of novel cardiovascular risk prediction models.

Yeast β-Glucan Improves Insulin Sensitivity and Hepatic Lipid Metabolism in Mice Humanized with Obese Type 2 Diabetic Gut Microbiota

SCOPE

Gut microbiota alterations are associated with obesity and type 2 diabetes. Yeast β-glucans are potential modulators of the innate immune-metabolic response, by impacting glucose, lipid, and cholesterol homeostasis. The study examines whether yeast β-glucan interacts differentially with either an obese healthy or obese diabetic gut microbiome, to impact metabolic health through hepatic effects under high-fat dietary challenge.

METHODS AND RESULTS

Male C57BL/6J mice are pre-inoculated with gut microbiota from obese healthy (OBH) or obese type 2 diabetic (OBD) subjects, in conjunction with a high-fat diet (HFD) with/without yeast β-glucan. OBD microbiome colonization adversely impacts metabolic health compared to OBH microbiome engraftment. OBD mice are more insulin resistant and display hepatic lipotoxicity compared to weight matched OBH mice. Yeast β-glucan supplementation resolves this adverse metabolic phenotype, coincident with increasing the abundance of health-related bacterial taxa. Hepatic proteomics demonstrates that OBD microbiome transplantation increases HFD-induced hepatic mitochondrial dysfunction, disrupts oxidative phosphorylation, and reduces protein synthesis, which are partly reverted by yeast β-glucan supplementation.

CONCLUSIONS

Hepatic metabolism is adversely affected by OBD microbiome colonization with high-fat feeding, but partially resolved by yeast β-glucan. More targeted dietary interventions that encompass the interactions between diet, gut microbiota, and host metabolism may have greater treatment efficacy.