Circulating Levels of microRNA-122 and Hepatic Fat Change in Response to Weight-Loss Interventions: CENTRAL Trial

A review on cell-free RNA profiling: Insights into metabolic diseases and predictive value for bariatric surgery outcomes

BACKGROUND

The advent of liquid biopsies presents a novel, minimally invasive methodology for the detection of disease biomarkers, offering a significant advantage over traditional biopsy techniques. Particularly, the analysis of cell-free RNA (cfRNA) has garnered interest due to its dynamic expression profiles and the capability to study various RNA species, including messenger RNA (mRNA) and long non-coding RNA (lncRNA). These attributes position cfRNA as a versatile biomarker with broad potential applications in clinical research and diagnostics.

SCOPE OF REVIEW

This review delves into the utility of cfRNA biomarkers as prognostic tools for obesity-related comorbidities, such as diabetes, dyslipidemia, and non-alcoholic fatty liver disease.

MAJOR CONCLUSIONS

We evaluate the efficacy of cfRNA in forecasting metabolic outcomes associated with obesity and in identifying patients likely to experience favorable clinical outcomes following bariatric surgery. Additionally, this review synthesizes evidence from studies examining circulating cfRNA across different physiological and pathological states, with a focus on its role in diabetes, including disease progression monitoring and treatment efficacy assessment. Through this exploration, we underscore the emerging relevance of cfRNA signatures in the context of obesity and its comorbidities, setting the stage for future investigative efforts in this rapidly advancing domain.

Nutritional Modulation of Hepcidin in the Treatment of Various Anemic States

Twenty years after its discovery, hepcidin is still considered the main regulator of iron homeostasis in humans. The increase in hepcidin expression drastically blocks the flow of iron, which can come from one's diet, from iron stores, and from erythrophagocytosis. Many anemic conditions are caused by non-physiologic increases in hepcidin. The sequestration of iron in the intestine and in other tissues poses worrying premises in view of discoveries about the mechanisms of ferroptosis. The nutritional treatment of these anemic states cannot ignore the nutritional modulation of hepcidin, in addition to the bioavailability of iron. This work aims to describe and summarize the few findings about the role of hepcidin in anemic diseases and ferroptosis, as well as the modulation of hepcidin levels by diet and nutrients.

Role of MicroRNAs in Dietary Interventions for Obesity and Obesity-Related Diseases

Obesity and related metabolic syndromes pose a serious threat to human health and quality of life. A proper diet is a safe and effective strategy to prevent and control obesity, thus maintaining overall health. However, no consensus exists on the connotations of proper diet, and it is attributed to various factors, including "nutritional dark matter" and the "matrix effect" of food. Accumulating evidence confirms that obesity is associated with the in vivo levels of miRNAs, which serve as potential markers and regulatory targets for obesity onset and progression; food-derived miRNAs can regulate host obesity by targeting the related genes or gut microbiota across the animal kingdom. Host miRNAs mediate food nutrient-gut microbiota-obesity interactions. Thus, miRNAs are important correlates of diet and obesity onset. This review outlines the recent findings on miRNA-mediated food interventions for obesity, thereby elucidating their potential applications. Overall, we provide new perspectives and views on the evaluation of dietary nutrition, which may bear important implications for dietary control and obesity prevention.

Circulating thrifty microRNA is related to insulin sensitivity, adiposity, and energy metabolism in adults with overweight and obesity: the POUNDS Lost trial

BACKGROUND

MicroRNA 128-1 (miR-128-1) was recently linked to the evolutionary adaptation to famine and identified as a thrifty microRNA that controls energy expenditure, contributing to obesity and impaired glucose metabolism.

OBJECTIVES

We investigated whether circulating miR-128-1-5p and its temporal changes in response to weight-loss diet interventions were related to regulating insulin resistance, adiposity, and energy expenditure in adults with overweight and obesity. We also examined whether habitual physical activity (PA) and different macronutrient intakes modified associations of changes in miR-128-1-5p with improved metabolic outcomes.

METHODS

This study included 495 adults who consumed weight-loss diets with different macronutrient intakes. Circulating levels of miR-128-1-5p were assessed at baseline and 6 mo after the interventions. Outcome measurements included changes in insulin resistance HOMA-IR, adiposity, and resting energy expenditure.

RESULTS

We observed significant relations between circulating miR-128-1-5p and the positive selection signals at the 2q21.3 locus assessed by the single nucleotide polymorphisms rs1446585 and rs4988235. Higher miR-128-1-5p levels were associated with greater HOMA-IR (β per 1 SD: 0.08 [SE 0.03]; P = 0.009), waist circumference (β, 1.16 [0.55]; P = 0.036), whole-body total % fat mass (β, 0.75 [0.30]; P = 0.013), and REE (β, 23 [11]; P = 0.037). In addition, higher miR-128-1-5p level was related to lower total PA index (β, -0.23 [0.07]; P = 0.001) and interacted with PA (Pinteraction < 0.05) on changes in HOMA-IR and adiposity. We found that greater increases in miR-128-1-5p levels after the interventions were associated with lesser improvements in HOMA-IR and adiposity in participants with no change/decreases in PA. Furthermore, we found that dietary fat (Pinteraction = 0.027) and protein (Pinteraction= 0.055) intakes modified relations between changes in miR-128-1-5p and REE.

CONCLUSIONS

Circulating thrifty miRNA was linked to regulating body fat, insulin resistance, and energy metabolism. Temporal changes in circulating miR-128-1-5p were associated with better weight-loss outcomes during the interventions; habitual PA and dietary macronutrient intake may modify such relations. This trial was registered at clinicaltrials.gov as NCT00072995.

Nutrition for precision health: The time is now

Precision nutrition has emerged as a boiling area of nutrition research, with a particular focus on revealing the individual variability in response to diets that is determined mainly by the complex interactions of dietary factors with the multi-tiered "omics" makeups. Reproducible findings from the observational studies and diet intervention trials have lent preliminary but consistent evidence to support the fundamental role of gene-diet interactions in determining the individual variability in health outcomes including obesity and weight loss. Recent investigations suggest that the abundance and diversity of the gut microbiome may also modify the dietary effects; however, considerable instability in the results from the microbiome research has been noted. In addition, growing studies suggest that a complicated multiomics algorithm would be developed by incorporating the genome, epigenome, metabolome, proteome, and microbiome in predicting the individual variability in response to diets. Moreover, precision nutrition would also scrutinize the role of biological (circadian) rhythm in determining the individual variability of dietary effects. The evidence gathered from precision nutrition research will be the basis for constructing precision health dietary recommendations, which hold great promise to help individuals and their health care providers create precise and effective diet plans for precision health in the future.

Epigenetics in Precision Nutrition

Precision nutrition is an emerging area of nutrition research, with primary focus on the individual variability in response to dietary and lifestyle factors, which are mainly determined by an individual’s intrinsic variations, such as those in genome, epigenome, and gut microbiome. The current research on precision nutrition is heavily focused on genome and gut microbiome, while epigenome (DNA methylation, non-coding RNAs, and histone modification) is largely neglected. The epigenome acts as the interface between the human genome and environmental stressors, including diets and lifestyle. Increasing evidence has suggested that epigenetic modifications, particularly DNA methylation, may determine the individual variability in metabolic health and response to dietary and lifestyle factors and, therefore, hold great promise in discovering novel markers for precision nutrition and potential targets for precision interventions. This review summarized recent studies on DNA methylation with obesity, diabetes, and cardiovascular disease, with more emphasis put in the relations of DNA methylation with nutrition and diet/lifestyle interventions. We also briefly reviewed other epigenetic events, such as non-coding RNAs, in relation to human health and nutrition, and discussed the potential role of epigenetics in the precision nutrition research.