The Role of Glucagon-Like Peptide-1 in Energy Homeostasis

The role of glucagon-like peptide-1 receptor agonists (GLP1-RAs) in the management of the hypertensive patient with metabolic syndrome: a position paper from the Korean society of hypertension

Obesity is the one of the most important components of metabolic syndrome. Because obesity related hypertension accounts for two thirds of essential hypertension, managing obesity and metabolic syndrome is a crucial task in the management of hypertension. However, the current non-pharmacological therapies have limitations for achieving or maintaining ideal body weight. Recently, glucagon-like peptide-1 receptor agonists (GLP1-RAs) have demonstrated excellent weight control effects, accompanied by corresponding reductions in blood pressure. GLP1-RAs have shown cardiovascular and renal protective effects in cardiovascular outcome trials both in primary and secondary prevention. In this document, the Korean Society of Hypertension intends to remark the current clinical results of GLP1-RAs and recommend the government and health-policy makers to define obesity as a disease and to establish forward-looking policies for GLP1-RA treatment for obesity treatment, including active reimbursement policies.

Gut Microbiota and Metabolic Syndrome: Relationships and Opportunities for New Therapeutic Strategies

Since its discovery, numerous studies have shown the role of the microbiota in well-being and disease. The gut microbiota represents an essential factor that plays a multidirectional role that affects not just the gut but also other parts of the body, including the brain, endocrine system, humoral system, immune system, and metabolic pathways, as well as host-microbiome interactions. Through a comprehensive analysis of existing literature using the desktop research methodology, this review elucidates the mechanisms by which gut microbiota dysbiosis contributes to metabolic dysfunction, including obesity, dyslipidaemia, hypertension, atherosclerosis, hyperuricemia, and hyperglycaemia. Furthermore, it examines the bidirectional communication pathways between gut microbiota and host metabolism, highlighting the role of microbial-derived metabolites, immune modulation, and gut barrier integrity in shaping metabolic homeostasis. Importantly, the review identifies promising therapeutic strategies targeting the gut microbiota as potential interventions for metabolic syndrome, including probiotics, prebiotics, symbiotics, dietary modifications, and faecal microbiota transplantation. By delineating the bidirectional interactions between gut microbiota and metabolic syndrome, the review not only advances our understanding of disease pathophysiology but also underscores the potential for innovative microbiota-based interventions to mitigate the global burden of metabolic syndrome and its associated complications.

Ginseng polysaccharide components attenuate obesity and liver lipid accumulation by regulating fecal microbiota and hepatic lysine degradation

The increasing incidence of obesity has led to widespread attention in the exploration of natural ingredients. Ginseng polysaccharides (PGP), the main components from Panax ginseng, have been reported potential effect to attenuate obesity and regulate lipid metabolism. In this study, we found that PGP inhibited the high-fat diet (HFD)-induced weight gain, fat ratio and fat tissue weight after 8-week administration. Serum and liver lipid analysis showed that PGP decreased the levels of triglyceride and total cholesterol, which was mediated by the inhibition of key genes for fatty acid and cholesterol metabolisms. Metabolomics studies showed that the inhibitory effect of PGP on liver lipid accumulation was significantly correlated with its regulation of citric acid cycle and lysine degradation. PGP regulated the expression of genes related to lysine degradation in both liver tissue and hepatocytes. In addition, PGP reshaped the composition of fecal microbiota at the genus and species levels in obese mice. Spearman's correlation analysis demonstrated that Staphylococcus sciuri, Staphylococcus lentus, and Pseudoflavonifractor sp. An85 may be the potential targets that PGP maintains the abundance of l-lysine against obesity. It concluded that PGP can attenuate obesity and liver lipid accumulation by regulating fecal microbiota and hepatic lysine degradation.

Correlation between intestinal flora and GLP-1 receptor agonist dulaglutide in type 2 diabetes mellitus treatment-A preliminary longitudinal study

GLP-1 receptor agonists (GLP-1 RA) are presently used as the first-line drugs for the clinical treatment of type 2 diabetes mellitus (T2DM). It can regulate blood glucose by stimulating insulin secretion and lowering glucagon levels. We used 16S rRNA amplicon sequencing to detect structural changes in the composition of the intestinal flora of newly diagnosed T2DM after 1 and 48 weeks of dulaglutide administration. Our research found no significant changes in the intestinal flora after the administration of dulaglutide for 1 week to subjects with newly diagnosed T2DM. Nevertheless, after 48 weeks of dulaglutide administration, the composition of the intestinal flora changed significantly, with a significant reduction in the abundance of intestinal flora. Furthermore, we found that fasting glucose levels, fasting c-peptide levels, HbA1c levels, and BMI are also closely associated with intestinal flora. This reveals that intestinal flora may be one of the mechanisms by which dulaglutide treats T2DM.

Physiological functions of poorly absorbed polyphenols via the glucagon-like peptide-1

Polyphenols are compounds of plant origin with several documented bioactivities related to health promotion. Some polyphenols are hard to be absorbed into the body due to their structural characteristics. This review focuses on the health beneficial effects of polyphenols mediated by intestinal hormones, particularly related to the systemic functions through the secretion of glucagon-like peptide-1 (GLP-1), an enteric hormone that stimulates postprandial insulin secretion. GLP-1 is secreted from L cells in the distal small intestine. Therefore, some poorly absorbed polyphenols are known to have the ability to act on the intestines and promote GLP-1 secretion. It has been reported that it not only reduces hyperglycemia but also prevents obesity by reduction of overeating and improves blood vessel function. This review discusses examples of health effects of polyphenols mediated by GLP-1 secretion.

The Characteristics, Mechanisms and Therapeutics: Exploring the Role of Gut Microbiota in Obesity

Presently, obesity has emerged as a significant global public health concern due to its escalating prevalence and incidence rates. The gut microbiota, being a crucial environmental factor, has emerged as a key player in the etiology of obesity. Nevertheless, the intricate and specific interactions between obesity and gut microbiota, along with the underlying mechanisms, remain incompletely understood. This review comprehensively summarizes the gut microbiota characteristics in obesity, the mechanisms by which it induces obesity, and explores targeted therapies centered on gut microbiota restoration.

Fecal fermentation and high-fat diet-induced obesity mouse model confirmed exopolysaccharide from Weissella cibaria PFY06 can ameliorate obesity by regulating the gut microbiota

Obesity associated with diet and intestinal dysbiosis is a worldwide public health crisis, and exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have prebiotic potential to ameliorate obesity. Therefore, the present study obtained LAB with the ability to produce high EPS, examined the structure of EPS, and explained its mechanism of alleviating obesity by in vivo and in vitro models. The results showed that Weissella cibaria PFY06 with a high EPS yield was isolated from strawberry juice, and pure polysaccharide (PFY06-EPS) was purified by Sephadex G-100. The structural characteristics of PFY06-EPS showed that the molecular weight was 8.08 × 10⁶ Da and composed of α-(1,6)-D glucosyl residues. An in vitro simulated human colon fermentation test demonstrated that PFY06-EPS increased the abundance of Prevotella and Bacteroides. Cell tests confirmed that PFY06-EPS after fecal fermentation inhibited fat accumulation by promoting the secretion of endogenous gastrointestinal hormones and insulin and inhibiting the secretion of inflammatory factors. Notably, PFY06-EPS reduced weight gain, fat accumulation, inflammatory reactions and insulin resistance in a high-fat diet-induced obesity mouse model and improved glucolipid metabolism. PFY06-EPS intervention reversed obesity-induced microflora disorders, such as reducing the Firmicutes/Bacteroides ratio and increasing butyrate-producing bacteria (Roseburia and Oscillibacter), and reduced endotoxemia to maintain intestinal barrier integrity. Therefore, in vivo and in vitro models showed that PFY06-EPS had potential as a prebiotic that may play an anti-obesity role by improving the function of the gut microbiota.

Microbiota-gut-brain axis: relationships among the vagus nerve, gut microbiota, obesity, and diabetes

AIMS

The purpose of this review is to explore the interconnected pathways of the microbiota-gut-brain axis (MGBA), focusing on the roles of the vagus nerve and glucagon like peptide-1 in appetite control, and in the development of obesity and diabetes.

METHODS

Type 2 diabetes mellitus (T2DM) and obesity are metabolic disorders whose prevalence has significantly increased in recent decades and is expected to increase every year, to pandemic proportions. These two pathologies often coexist and have substantial public health implications. The term "diabesity" defines the pathophysiological connection between overweight and T2DM. The gut microbiota affects many aspects of the host. Beyond the regulation of intestinal functions and the activation of immune responses, the gut microbiota plays a role in central nervous system functions (i.e., mood, and psychiatric conditions associated with stress and memory) and is a central regulator of metabolism and appetite.

RESULTS

The MGBA involves pathways such as the autonomic and enteric nervous systems, the hypothalamic- pituitary-adrenal axis, the immune system, enteroendocrine cells, and microbial metabolites. Notably, the vagus nerve plays an essential role in eating behavior by modulating appetite and learning nutritional preferences.

CONCLUSIONS

Because of its enteroendocrine cell-mediated interaction with the gut microbiota, the vagus nerve may provide a potential pathway through which gut microorganisms influence host feeding behavior and metabolic control of physiological and pathological conditions.

Extensive Summary of the Important Roles of Indole Propionic Acid, a Gut Microbial Metabolite in Host Health and Disease

Increasing evidence suggests that metabolites produced by the gut microbiota play a crucial role in host-microbe interactions. Dietary tryptophan ingested by the host enters the gut, where indole-like metabolites such as indole propionic acid (IPA) are produced under deamination by commensal bacteria. Here, we summarize the IPA-producing bacteria, dietary patterns on IPA content, and functional roles of IPA in various diseases. IPA can not only stimulate the expression of tight junction (TJ) proteins to enhance gut barrier function and inhibit the penetration of toxic factors, but also modulate the immune system to exert anti-inflammatory and antioxidant effects to synergistically regulate body physiology. Moreover, IPA can act on target organs through blood circulation to form the gut-organ axis, which helps maintain systemic homeostasis. IPA shows great potential for the diagnosis and treatment of various clinical diseases, such as NAFLD, Alzheimer's disease, and breast cancer. However, the therapeutic effect of IPA depends on dose, target organ, or time. In future studies, further work should be performed to explore the effects and mechanisms of IPA on host health and disease to further improve the existing treatment program.

Intake of slow-digesting carbohydrates is related to changes in the microbiome and its functional pathways in growing rats with obesity induced by diet

INTRODUCTION

The main cause of insulin resistance in childhood is obesity, which contributes to future comorbidities as in adults. Although high-calorie diets and lack of exercise contribute to metabolic disease development, food quality rather than the quantity of macronutrients is more important than food density. The purpose of the present study was to examine the effects of changing the quality of carbohydrates from rapidly to slowly digestible carbohydrates on the composition of the gut microbiota and the profiles of the functional pathways in growing rats with obesity due to a high-fat diet (HFD).

METHODS

During the course of 4 weeks, rats growing on an HFD-containing carbohydrates with different digestive rates were fed either HFD-containing carbohydrates with a rapid digestion rate (OBE group) or HFD-containing carbohydrates with a slow digestion rate (OBE-ISR group). A non-obese group (NOB) was included as a reference, and rats were fed on a rodent standard diet (AIN93G). An analysis of gut microbiota was conducted using 16S rRNA-based metagenomics; a linear mixed-effects model (LMM) was used to determine changes in abundance between baseline and 4 weeks of treatment, and functional pathways were identified. Gut microbiota composition at bacterial diversity and relative abundance, at phylum and genus levels, and functional profiles were analyzed by integrating the Integrated Microbial Genomes (IMG) database.

RESULTS

The groups showed comparable gut microbiota at baseline. At the end of the treatment, animals from the ISR group exhibited differences at the phylum levels by decreasing the diversity of Fisher's index and Firmicutes (newly named as Bacillota), and increasing the Pielou's evenness and Bacteroidetes (newly named as Bacteroidota); at the genus level by increasing Alistipes, Bifidobacterium, Bacteroides, Butyricimonas, Lachnoclostridium, Flavonifractor, Ruminiclostridium 5, and Faecalibaculum and decreasing Muribaculum, Blautia, and Ruminiclostridium 9. Remarkably, relative abundances of genera Tyzzerella and Angelakisella were higher in the OBE group compared to NOB and OBE-ISR groups. In addition, some microbiota carbohydrate metabolism pathways such as glycolysis, glucuronic acid degradation, pentose phosphate pathway, methanogenesis, and fatty acid biosynthesis exhibited increased activity in the OBE-ISR group after the treatment. Higher levels of acetate and propionate were found in the feces of the ISR group compared with the NOB and OBE groups.

CONCLUSION

The results of this study demonstrate that replacing rapidly digestible carbohydrates with slowly digestible carbohydrates within an HFD improve the composition of the gut microbiota. Consequently, metabolic disturbances associated with obesity may be prevented.

Role of brain-gut-muscle axis in human health and energy homeostasis

The interrelationship between brain, gut and skeletal muscle plays a key role in energy homeostasis of the body, and is becoming a hot topic of research. Intestinal microbial metabolites, such as short-chain fatty acids (SCFAs), bile acids (BAs) and tryptophan metabolites, communicate with the central nervous system (CNS) by binding to their receptors. In fact, there is a cross-talk between the CNS and the gut. The CNS, under the stimulation of pressure, will also affect the stability of the intestinal system, including the local intestinal transport, secretion and permeability of the intestinal system. After the gastrointestinal tract collects information about food absorption, it sends signals to the central system through vagus nerve and other channels to stimulate the secretion of brain-gut peptide and produce feeding behavior, which is also an important part of maintaining energy homeostasis. Skeletal muscle has receptors for SCFAs and BAs. Therefore, intestinal microbiota can participate in skeletal muscle energy metabolism and muscle fiber conversion through their metabolites. Skeletal muscles can also communicate with the gut system during exercise. Under the stimulation of exercise, myokines secreted by skeletal muscle causes the secretion of intestinal hormones, and these hormones can act on the central system and affect food intake. The idea of the brain-gut-muscle axis is gradually being confirmed, and at present it is important for regulating energy homeostasis, which also seems to be relevant to human health. This article focuses on the interaction of intestinal microbiota, central nervous, skeletal muscle energy metabolism, and feeding behavior regulation, which will provide new insight into the diagnostic and treatment strategies for obesity, diabetes, and other metabolic diseases.

The Role of Nutritional Status, Gastrointestinal Peptides, and Endocannabinoids in the Prognosis and Treatment of Children with Cancer

Neoplastic diseases in children are the second most frequent cause of death among the young. It is estimated that 400,000 children worldwide will be diagnosed with cancer each year. The nutritional status at diagnosis is a prognostic indicator and influences the treatment tolerance. Both malnutrition and obesity increase the risk of mortality and complications during treatment. It is necessary to constantly search for new factors that impair the nutritional status. The endocannabinoid system (ECS) is a signaling system whose best-known function is regulating energy balance and food intake, but it also plays a role in pain control, embryogenesis, neurogenesis, learning, and the regulation of lipid and glucose metabolism. Its action is multidirectional, and its role is being discovered in an increasing number of diseases. In adults, cannabinoids have been shown to have anti-cancer properties against breast and pancreatic cancer, melanoma, lymphoma, and brain tumors. Data on the importance of both the endocannabinoid system and synthetic cannabinoids are lacking in children with cancer. This review highlights the role of nutritional status in the oncological treatment process, and describes the role of ECS and gastrointestinal peptides in regulating appetite. We also point to the need for research to evaluate the role of the endocannabinoid system in children with cancer, together with a prospective assessment of nutritional status during oncological treatment.

Gut microbiota in obesity

Obesity is a major global health problem determined by heredity and environment, and its incidence is increasing yearly. In recent years, increasing evidence linking obesity to the gut microbiota has been reported. Gut microbiota management has become a new method of obesity treatment. However, the complex interactions among genetics, environment, the gut microbiota, and obesity remain poorly understood. In this review, we summarize the characteristics of the gut microbiota in obesity, the mechanism of obesity induced by the gut microbiota, and the influence of genetic and environmental factors on the gut microbiota and obesity to provide support for understanding the complex relationship between obesity and microbiota. At the same time, the prospect of obesity research related to the gut microbiota is proposed.

Ramulus Mori (Sangzhi) Alkaloids (SZ-A) Ameliorate Glucose Metabolism Accompanied by the Modulation of Gut Microbiota and Ileal Inflammatory Damage in Type 2 Diabetic KKAy Mice

The novel Traditional Chinese Medicine Ramulus Mori (Sangzhi) alkaloid tablets (SZ-A) are approved by The China National Medical Products Administration for the treatment of type 2 diabetes mellitus (T2DM). However, the extensive pharmacological characteristics and the underlying mechanism are unknown. This study investigated the mechanisms by which SZ-A ameliorates glucose metabolism in KKAy mice, an animal model of T2DM. Diabetic KKAy mice were treated intragastrically with SZ-A once daily for 8 weeks, after which glucose levels, lipid metabolism, gut microbiome, systemic inflammatory factors, luminal concentrations of short-chain fatty acids (fecal samples), and ileal proteomic changes were evaluated. The ileum tissues were collected, and the effects of SZ-A on pathological inflammatory damage were evaluated by hematoxylin and eosin staining, immunofluorescence, and immunohistochemistry. The mRNA and protein expression levels of various inflammatory markers, including monocyte chemoattractant protein-1 and phosphorylated nuclear factor kappa B p65, were detected in the ileum tissues. SZ-A improved glucose metabolism with enhanced insulin response and elevated glucagon-like peptide 1 (GLP-1) nearly 2.7-fold during the glucose tolerance test in diabetic KKAy mice. Gut microbiota analysis demonstrated that SZ-A administration elevated the abundance of Bacteroidaceae and Verrucomicrobia, reduced the levels of Rikenellaceae and Desulfovibrionaceae; and increased the concentrations of fecal acetic and propionic acids compared to the diabetic model group. Additionally, SZ-A markedly improved ileal inflammatory injury and pro-inflammatory macrophage infiltration and improved intestinal mucosal barrier function in diabetic KKAy mice. SZ-A also attenuated the levels of circulating endotoxin, pro-inflammatory cytokines, and chemokines in the mice sera. Collectively, SZ-A ameliorated the overall metabolic profile including glucose and lipid metabolism in KKAy mice, which may be associated with an improvement in GLP-1 and insulin secretion, at least in part by modulating the gut microbiome and relieving the degree of ileal and systemic inflammation.

An Exploration of the Role of Sugar-Sweetened Beverage in Promoting Obesity and Health Disparities

PURPOSE OF REVIEW

The mechanistic role of sugar-sweetened beverage (SSB) in the etiology of obesity is undetermined. We address whether, compared to other foods, does consumption of SSB (1) automatically lead to failure to compensate for the energy it contains? (2) fail to elicit homeostatic hormone responses? (3) promote hedonic eating through activation of the brain's reward pathways? We followed the evidence to address: (4) Would restriction of targeted marketing of SSB and other unhealthy foods to vulnerable populations decrease their prevalence of obesity?

RECENT FINDINGS

The data are lacking to demonstrate that SSB consumption promotes body weight gain compared with isocaloric consumption of other beverages or foods and that this is linked to its failure to elicit adequate homeostatic hormone responses. However, more recent data have linked body weight gain to reward activation in the brain to palatable food cues and suggest that sweet tastes and SSB consumption heightens the reward response to food cues. Studies investigating the specificity of these responses have not been conducted. Nevertheless, the current data provide a biological basis to the body of evidence demonstrating that the targeted marketing (real life palatable food cues) of SSB and other unhealthy foods to vulnerable populations, including children and people of color and low socioeconomic status, is increasing their risk for obesity. While the mechanisms for the association between SSB consumption and body weight gain cannot be identified, current scientific evidence strongly suggests that proactive environmental measures to reduce exposure to palatable food cues in the form of targeting marketing will decrease the risk of obesity in vulnerable populations.

Resveratrol Modulates the Gut-Brain Axis: Focus on Glucagon-Like Peptide-1, 5-HT, and Gut Microbiota

Resveratrol is a natural polyphenol that has anti-aging and anti-inflammatory properties against stress condition. It is reported that resveratrol has beneficial functions in various metabolic and central nervous system (CNS) diseases, such as obesity, diabetes, depression, and dementia. Recently, many researchers have emphasized the connection between the brain and gut, called the gut-brain axis, for treating both CNS neuropathologies and gastrointestinal diseases. Based on previous findings, resveratrol is involved in glucagon-like peptide 1 (GLP-1) secreted by intestine L cells, the patterns of microbiome in the intestine, the 5-hydroxytryptamine (5-HT) level, and CNS inflammation. Here, we review recent evidences concerning the relevance and regulatory function of resveratrol in the gut-brain axis from various perspectives. Here, we highlight the necessity for further study on resveratrol's specific mechanism in the gut-brain axis. We present the potential of resveratrol as a natural therapeutic substance for treating both neuropathology and gastrointestinal dysfunction.

Sennoside A Induces GLP-1 Secretion Through Activation of the ERK1/2 Pathway in L-Cells

PURPOSE

Glucagon-like peptide-1 (GLP-1) is secreted from the intestinal L-cells to stimulate insulin secretion in the blood glucose control. Our previous study indicates that Sennoside A (SA) can increase the plasma GLP-1 level in a mouse model of type 2 diabetes. However, the mechanism of SA activity remains largely unknown. This issue was explored in this study.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into four groups: a control group without drug treatment, and the other groups with different SA dosages, respectively. Blood glucose was assayed by oral glucose tolerance test (OGTT). Plasma GLP-1 and insulin were investigated. Colon tissues were collected for mRNA or Western blot analysis. Immunofluorescence staining assays were performed to evaluate the number of β-cells and L-cells. In NCI-H716 cells, extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitors were employed to investigate the SA-induced GLP-1 secretion mechanism.

RESULTS

In this work, the SA was found to improve OGTT in mice. Plasma GLP-1 and insulin were markedly elevated by SA at the dosage of 45 mg/kg/day. Meanwhile, the increased phosphorylation status of EKR1/2 and prohormone convertase 1/3 (PC1/3) proteins were observed in the colon of SA-treated mice. The number of L-cells exhibited no change in each group. In the NCI-H716 cells, GLP-1 secretion induced by SA was blocked by the ERK1/2 inhibitor.

CONCLUSION

The present study provides a direct evidence for the interaction between SA and L cells for induction of GLP-1 secretion. These data suggest that GLP-1 secretion induced by SA is dependent on the ERK1/2 signaling pathway. Therefore, the SA is a new drug candidate for the type 2 diabetes treatment by induction of GLP-1 secretion.