Safety and efficacy of hydrothermal duodenal mucosal resurfacing in patients with type 2 diabetes: the randomised, double-blind, sham-controlled, multicentre REVITA-2 feasibility trial

American Society for Gastrointestinal Endoscopy-European Society of Gastrointestinal Endoscopy guideline on primary endoscopic bariatric and metabolic therapies for adults with obesity

This joint ASGE-ESGE guideline provides an evidence-based summary and recommendations regarding the role of endoscopic bariatric and metabolic therapies (EBMTs) in the management of obesity. The document was developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. It evaluates the efficacy and safety of EBMT devices and procedures that currently have CE mark or FDA-clearance/approval, or that had been approved within five years of document development. The guideline suggests the use of EBMTs plus lifestyle modification in patients with a BMI of ≥ 30 kg/m2, or with a BMI of 27.0-29.9 kg/m2 with at least 1 obesity-related comorbidity. Furthermore, it suggests the utilization of intragastric balloons and devices for endoscopic gastric remodeling (EGR) in conjunction with lifestyle modification for this patient population.

A look at duodenal mucosal resurfacing: Rationale for targeting the duodenum in type 2 diabetes

Affecting 5%-10% of the world population, type 2 diabetes (T2DM) is firmly established as one of the major health burdens of modern society. People with T2DM require long-term therapies to reduce blood glucose, an approach that can mitigate the vascular complications. However, fewer than half of those living with T2DM reach their glycaemic targets despite the availability of multiple oral and injectable medications. Adherence and access to medications are major barriers contributing to suboptimal diabetes treatment. The gastrointestinal tract has recently emerged as a target for treating T2DM and altering the underlying disease course. Preclinical and clinical analyses have elucidated changes in the mucosal layer of the duodenum potentially caused by dietary excess and obesity, which seem to be prevalent among individuals with metabolic disease. Supporting these findings, gastric bypass, a surgical procedure which removes the duodenum from the intestinal nutrient flow, has remarkable effects that improve, and often cause remission of, diabetes. From this perspective, we explore the rationale for targeting the duodenum with duodenal mucosal resurfacing (DMR). We examine the underlying physiology of the duodenum and its emerging role in T2DM pathogenesis, the rationale for targeting the duodenum by DMR as a potential treatment for T2DM, and current data surrounding DMR. Importantly, DMR has been demonstrated to change mucosal abnormalities common in those with obesity and diabetes. Given the multifactorial aetiology of T2DM, understanding proximate contributors to disease pathogenesis opens the door to rethinking therapeutic approaches to T2DM, from symptom management toward disease modification.

American Society for Gastrointestinal Endoscopy-European Society of Gastrointestinal Endoscopy guideline on primary endoscopic bariatric and metabolic therapies for adults with obesity

This joint ASGE-ESGE guideline provides an evidence-based summary and recommendations regarding the role of endoscopic bariatric and metabolic therapies (EBMTs) in the management of obesity. The document was developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. It evaluates the efficacy and safety of EBMT devices and procedures that currently have CE mark or FDA-clearance/approval, or that had been approved within five years of document development. The guideline suggests the use of EBMTs plus lifestyle modification in patients with a BMI of ≥30 kg/m2, or with a BMI of 27.0-29.9 kg/m2 with at least 1 obesity-related comorbidity. Furthermore, it suggests the utilization of intragastric balloons and devices for endoscopic gastric remodeling (EGR) in conjunction with lifestyle modification for this patient population.

Role of the Intestine and Its Gut Microbiota in Metabolic Syndrome and Obesity

The metabolic syndrome (MetSyn) is currently one of the biggest global health challenges because of its impact on public health. MetSyn includes the cluster of metabolic disorders including obesity, high blood pressure, hyperglycemia, high triglyceride levels, and hepatic steatosis. Together, these abnormalities increase the cardiovascular risk of individuals and pose a threat to healthcare systems worldwide. To better understand and address this complex issue, recent research has been increasingly focusing on unraveling the delicate interplay between metabolic disorders and the intestines and more specifically our gut microbiome. The gut microbiome entails all microorganisms inhabiting the gastrointestinal tract and plays a pivotal role in metabolic processes and overall health of its host. Emerging evidence proves an association between the gut microbiome composition and aspects of MetSyn, such as obesity. Understanding these relationships is crucial because they offer valuable insights into the mechanisms underlying development and progression of metabolic disorders and possible treatment options. Yet, how should we interpret this relationship? This review focuses on the interplay between the gut and MetSyn. In addition, we have reviewed the existing evidence of the gut microbiome and its association with and impact on metabolic disorders, in an attempt to understand the complex interactions and nature of this association. We also explored potential therapeutic options targeting the gut to modify metabolic disorders and obesity.

Endoscopic transoral outlet reduction induces enterohormonal changes in patients with weight regain after Roux-en-Y gastric bypass

Background and study aims Transoral outlet reduction (TORe) has long been employed in treating weight regain after Roux-en-Y gastric bypass. However, its impact on gut hormones and their relationship with weight loss remains unknown. Patients and methods This was a substudy of a previous randomized clinical trial. Adults with significant weight regain and dilated gastrojejunostomy underwent TORe with argon plasma coagulation (APC) alone or APC plus endoscopic suturing (APC-suture). Serum levels of ghrelin, GLP-1, and PYY were assessed at fasting, 30, 60, 90, and 120 minutes after a standardized liquid meal. Results were compared according to allocation group, clinical success, and history of cholecystectomy. Results Thirty-six patients (19 APC vs. 17 APC-suture) were enrolled. There were no significant baseline differences between groups. In all analyses, the typical postprandial decrease in ghrelin levels was delayed by 30 minutes, but no other changes were noted. GLP-1 levels significantly decreased at 12 months in both allocation groups. Similar findings were noted after dividing groups according to the history of cholecystectomy and clinical success. The APC cohort presented an increase in PYY levels at 90 minutes, while the APC-suture group did not. Naïve patients had significantly lower PYY levels at baseline ( P = 0.01) compared with cholecystectomized individuals. This latter group experienced a significant increase in area under the curve (AUC) for PYY levels, while naïve patients did not, leading to a higher AUC at 12 months ( P = 0.0001). Conclusions TORe interferes with the dynamics of gut hormones. APC triggers a more pronounced enteroendocrine response than APC-suture, especially in cholecystectomized patients.

Bariatrics and endoscopic therapies for the treatment of metabolic disease: Past, present, and future

The burden of chronic metabolic diseases such as obesity, type 2 diabetes mellitus (T2DM), and metabolic dysfunction-associated steatotic liver disease (MASLD) and the urgency of the epidemiological situation necessitate the development of therapies that enhance metabolic health and alter the trajectory of metabolic disease in society. Certain bariatric-metabolic surgeries have proven to be effective approaches for treating metabolic dysfunction, showing remission or significant improvements in obesity, T2DM, and MASLD-related outcomes, suggesting that these interventions might be able to "reset" a pathologically calibrated metabolic setpoint. However, considering the challenges and invasiveness of surgery, endoscopic bariatric metabolic therapies (EBMTs) have emerged with a primary focus to reconstruct or mimic anatomical and/or functional changes observed with bariatric surgery in a more broadly accessible manner. These innovative approaches offer a potentially promising solution to address significant unmet medical need in the large segment of society, which remains at risk for the consequences of metabolic diseases. In this review, we discuss therapeutic options within the EBMT space in the context of the metabolic setpoint intellectual model and provide a brief overview of current knowledge surrounding their mechanisms of action and impact on metabolic health. Finally, we explore future perspectives and directions in this exciting field.

Endoscopic duodenal mucosa ablation techniques for diabetes and nonalcoholic fatty liver disease: A systematic review

BACKGROUND

Type 2 diabetes mellitus (T2DM) is increasing at an alarming rate, and only 50% of patients with T2DM achieve or maintain adequate glycemic control with pharmacological therapies. Metabolic surgery demonstrated superior efficacy compared to medical therapy but is unfeasible for most patients with T2DM. Duodenal mucosal resurfacing (DMR) by hydrothermal mucosal ablation, recellularization via electroporation therapy (ReCET), and photodynamic therapy are novel endoscopic procedures that use thermal, electrical, and photochemical energy, respectively, to ablate and reset dysfunctional duodenal mucosa. We assessed the data on the effects of these techniques on glycemic control and nonalcoholic fatty liver disease (NAFLD).

METHODS

We systematically searched independently and in duplicate English and non-English language publications through January 31st, 2024. Outcomes assessed were an improvement in different metabolic health parameters and the safety of duodenal mucosal ablation (DMA) procedures. Outcomes were presented descriptively.

FINDINGS

We selected 12 reports reporting results from 3 randomized and 6 uncontrolled trials (seven evaluating DMR, two evaluating ReCET, all with a low risk of bias) for a total of 317 patients enrolled. DMA reduced HbA1c, fasting plasma glucose, and liver fat. When combined with newer antidiabetic drugs, it allowed insulin discontinuation in up to 86% patients. No major safety signal emerged.

CONCLUSIONS

All DMA techniques improve glucose homeostasis; DMR and ReCET appear to be safe in patients with T2DM. If confirmed by future randomized trials and by trials with histological endpoints in NAFLD, then DMA appears to be a promising alternative or complement option to medications for T2DM and NAFLD treatment.

FUNDING

This study received no funding.

Updates in metabolic bariatric endoscopy

Obesity and its associated comorbid conditions have been increasing globally. Endoscopic bariatric and metabolic therapies (EBMTs) were initially designed to replicate bariatric surgery physiology for those who are not or choose not to be surgical candidates. Now, newer procedures target the complicated pathophysiology underlying obesity and its comorbidities. EBMT has been categorized based on its therapeutic target (stomach or small intestine), but innovations have expanded to include extraintestinal organs including the pancreas. Gastric EBMTs, namely space-occupying balloons, gastroplasty with suturing or plication, and aspiration therapy, are primarily used for weight loss. Small bowel EBMTs are designed to cause malabsorption, epithelial endocrine remodeling, and other changes to intestinal physiology to ultimately improve the metabolic comorbidities of obesity rather than induce weight loss alone. These include duodenal mucosal resurfacing, endoluminal bypass sleeves, and incisionless anastomosis systems. Extraluminal or pancreatic EBMT is aimed to restore the production of normal pancreatic proteins that are involved in the progression of type 2 diabetes. This review discusses the current and new technologies of metabolic bariatric endoscopy, their pros and cons, and areas for future research.

Chronic Stress as a Risk Factor for Type 2 Diabetes: Endocrine, Metabolic, and Immune Implications

BACKGROUND

Chronic stress is a condition of pressure on the brain and whole body, which in the long term may lead to a frank disease status, even including type 2 diabetes (T2D). Stress activates the hypothalamus-pituitary-adrenal axis with release of glucocorticoids (GCs) and catecholamines, as well as activation of the inflammatory pathway of the immune system, which alters glucose and lipid metabolism, ultimately leading to beta-cell destruction, insulin resistance and T2D onset. Alteration of the glucose and lipid metabolism accounts for insulin resistance and T2D outcome. Furthermore, stress-related subversion of the intestinal microbiota leads to an imbalance of the gut-brain-immune axis, as evidenced by the stress-related depression often associated with T2D. A condition of generalized inflammation and subversion of the intestinal microbiota represents another facet of stress-induced disease. In fact, chronic stress acts on the gut-brain axis with multiorgan consequences, as evidenced by the association between depression and T2D. Oxidative stress with the production of reactive oxygen species and cytokine-mediated inflammation represents the main hallmarks of chronic stress. ROS production and pro-inflammatory cytokines represent the main hallmarks of stress-related disorders, and therefore, the use of natural antioxidant and anti-inflammatory substances (nutraceuticals) may offer an alternative therapeutic approach to combat stress-related T2D. Single or combined administration of nutraceuticals would be very beneficial in targeting the neuro-endocrine-immune axis, thus, regulating major pathways involved in T2D onset. However, more clinical trials are needed to establish the effectiveness of nutraceutical treatment, dosage, time of administration and the most favorable combinations of compounds. Therefore, in view of their antioxidant and anti-inflammatory properties, the use of natural products or nutraceuticals for the treatment of stress-related diseases, even including T2D, will be discussed. Several evidences suggest that chronic stress represents one of the main factors responsible for the outcome of T2D.

MASLD treatment-a shift in the paradigm is imminent

MASLD prevalence is growing towards the leading cause of end-stage liver disease. Up to today, the most effective treatment is weight loss. Weight loss interventions are moving from lifestyle changes to bariatric surgery or endoscopy, and, more recently, to a new wave of anti-obesity drugs that can compete with bariatric surgery. Liver-targeted therapy is a necessity for those patients who already present liver fibrosis. The field is moving fast, and in the near future, we will testify to a disruptive change in MASLD treatment, similar to the paradigm-shift that occurred for hepatitis C almost one decade ago with direct antiviral agents.

Duodenal mucosal resurfacing with photodynamic therapy using methylene blue in a mouse model

BACKGROUND

The duodenum has emerged as a key player in metabolic diseases. The objective was to evaluate the safety and efficacy of intra-duodenal PDT using methylene blue in managing glycemic control and weight reduction.

METHODS

Optimal concentration of methylene blue and conditions for intra-duodenal PDT were determined through in vitro experiments. After injecting methylene blue into the duodenum, we performed intra-duodenal PDT. High-fat diet rats were used to assess the efficacy of intra-duodenal PDT through measures of oral glucose tolerance, insulin sensitivity, and weight change. Immunohistochemical staining was also conducted to examine GLP-1 and GIP-producing cells in the ileum and duodenum, respectively.

RESULTS

Introduodenal PDT reduced villous height of duodenum at 48 h, which was fully recovered at 30 days without complications. Rats treated with PDT showed significantly lower blood glucose levels with glucose loading and improved insulin sensitivity than rats in the sham-treatment group. The PDT group also had a significant reduction in body weight compared to the sham-treatment group at 30 days after intervention, although food intake was not significantly different between the two groups. Numbers of GLP-1 and GIP producing cells in the ileum and irradiated area were significantly higher in the PDT group than in the sham-treatment group.

CONCLUSIONS

Intra-duodenal PDT using methylene blue showed a feasible therapeutic modality in improving metabolic parameters. However, large animal experiments and mechanism studies are needed to determine the clinical relevance. The possibility of repeating this treatment every 30 days and its accompanying complications should be further studied.

Unraveling the link between insulin resistance and Non-alcoholic fatty liver disease (or metabolic dysfunction-associated steatotic liver disease): A Narrative Review

Objective

Non-alcoholic fatty liver disease (NAFLD) is rapidly becoming a significant global health concern, representing the leading cause of chronic liver disease and posing a substantial public health challenge. NAFLD is associated with higher insulin resistance (IR) levels, a key pathophysiological mechanism contributing to its development and progression. To counter this growing trend, it is crucial to raise awareness about NAFLD and promote healthy lifestyles to mitigate the impact of this disease.

Methods

Relevant studies regarding IR and NAFLD published until May 30, 2023, were extracted from Google PubMed, Scopus, and Web Of Science web databases. The following keywords were used: IR, diabetes mellitus, Non-alcoholic fatty liver disease, and metabolic syndrome.

Results

IR leads to an accumulation of fatty acids within liver cells, resulting from increased glycolysis and decreased apolipoprotein B-100. Furthermore, the manifestations of NAFLD extend beyond liver-related morbidity and mortality, affecting multiple organs and giving rise to various non-communicable disorders such as diabetes mellitus, metabolic syndrome, polycystic ovary syndrome, obstructive sleep apnea, and cardiovascular disease. Although lifestyle modification remains the primary treatment approach for NAFLD, alternative therapies, including pharmacological, herbal, and surgical interventions, may be considered. By implementing early and simple measures, cirrhosis, end-stage liver disease, and hepatocellular carcinoma can be prevented.

Conclusions

There is a clear association between NAFLD and elevated levels of IR. Several metabolic conditions, such as obesity, type 2 diabetes mellitus, dyslipidemia, and metabolic syndrome, are closely interrelated with NAFLD and IR. Raising awareness about NAFLD and promoting a healthy lifestyle are crucial steps to reverse the impact of this disease.

Surfactant-like photosensitizer for endoscopic duodenal ablation: Modulating meal-stimulated incretin hormones in obese and type 2 diabetes

Duodenal ablation improves glycaemic control and weight loss, so it has been applied using hydrothermal catheters in obese and type 2 diabetes patients, indicating similar mechanisms and therapeutic effects as bariatric surgeries. Endoscopic photodynamic therapy is an innovative procedure that easily accessible to endocrine or gastrointestinal organs, so it is critical for the sprayed photosensitizer (PS) to long-term interact with target tissues for enhancing its effects. Surfactant-like PS was more stable in a wide range of pH and 2.8-fold more retained in the duodenum at 1 h than hydrophilic PS due to its amphiphilic property. Endoscopic duodenal ablation using surfactant-like PS was performed in high fat diet induced rat models, demonstrating body weight loss, enhanced insulin sensitivity, and modulation of incretin hormones. Locoregional ablation of duodenum could affect the profiles of overall intestinal cells secreting meal-stimulated hormones and further the systemic glucose and lipid metabolism, regarding gut-brain axis. Our strategy suggests a potential for a treatment of minimally invasive bariatric and metabolic therapy if accompanied by detailed clinical trials.

The metabolic influence of duodenal mucosal resurfacing for nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease worldwide with decreased life expectancy. Duodenal mucosal resurfacing (DMR) has been associated with metabolic improvement in glycemic and hepatic parameters of type 2 diabetes, but the metabolic impact of DMR for NAFLD/NASH remains inconclusive. We conducted a meta-analysis to investigate metabolic effects of DMR in patients with NAFLD/NASH.

METHODS

Three major bibliographic databases were reviewed for enrollment of trials prior to January 28, 2022. We included adults with biopsy-proven NAFLD/NASH or liver magnetic resonance imaging proton density fat fraction (MRI-PDFF) >5% at baseline and focused on the metabolic difference of MRI-PDFF at 12 weeks, and HbA1c or homeostatic model assessment index for insulin resistance (HOMA-IR) at 24 weeks.

RESULTS

Two studies involved a total of 67 participants for analysis. When compared with pre-intervention status, mean difference of MRI-PDFF, HbA1c, and HOMA-IR after DMR were -2.22 (95% CI: -12.79~8.34), -0.32% (95% CI: -0.80~0.16), and 0.15 (95% CI: -5.11~5.41) without statistical significance.

CONCLUSIONS

For patients with NAFLD/NASH, DMR has the trend to improve liver fat at 12 weeks, and glycemic control in terms of HbA1c level at 24 weeks based on a very low quality of evidence.

Metabolic and Bariatric Endoscopy: A Mini-Review

We are currently in a worldwide obesity pandemic, which is one of the most significant health problems of the 21st century. As the prevalence of obesity continues to rise, new and innovate treatments are becoming available. Metabolic and bariatric endoscopic procedures are exciting new areas of gastroenterology that have been developed as a direct response to the obesity crisis. These novel interventions offer a potentially reversible, less invasive, safer, and more cost-effective method of tackling obesity compared to traditional bariatric surgery. Minimally invasive endoscopic treatments are not entirely novel, but as technology has rapidly improved, many of the procedures have been proven to be extremely effective for weight loss and metabolic health, based on high-quality clinical trial data. This mini-review examines the existing evidence for the most prominent metabolic and bariatric procedures, followed by a discussion on the future trajectory of this emerging subspecialty.

Small intestine-targeted endoscopic bariatrics: Current status and future perspectives

The global obesity epidemic shows no signs of slowing down. Endoscopic bariatric and metabolic therapies (EBMTs) are being increasingly adopted as treatment options for obesity and obesity-related comorbidities, due to their minimally invasive nature and ease of delivery. According to the site of action along the gastrointestinal tract, EBMTs can be divided into two categories: gastric EBMTs, and small intestine-targeted EBMTs. Unlike gastric EBMTs, which work through a volume-restricting mechanism leading to early satiety and reduced caloric intake, small intestine-targeted EBMTs can be metabolically beneficial through foregut and/or hindgut pathways independent of weight loss, and therefore have great potential for the treatment of obesity-related metabolic comorbidities such as type 2 diabetes. Although none of the small intestine-targeted EBMTs have been approved by the US Food and Drug Administration to date, their clinical efficacy and safety have been extensively explored in investigational trials. This review aims to summarize and provide a comprehensive understanding of small intestine-targeted EBMTs in clinical and preclinical settings, and to further discuss their potential mechanisms of action.

Removable Transduodenal Bypass: Development of a New Endoscopic Concept

Introduction

Obesity and obesity-related disease such as diabetes mellitus type 2 are a permanently rising concern worldwide. Current effective therapeutic options mostly include medication and surgery, but there is a lack of effective treatment options between medication and surgery. Previously, devices such as EndoBarrier® have been placed on the market. However, high complication rates, especially liver abscesses, were seen in patients after implantation of the device. Nevertheless, duodenal lining seems to be an effective therapy for type 2 diabetes in obese patients and can lead to weight loss.

Methods

A new removable transduodenal bypass was developed and tested on a porcine model. In this course, the device evolved in its mechanism and handling. The device is designed to avoid typical complications seen in previous duodenal liners.

Results

After further development of the device, implantation and use were feasible and safe in the porcine model. Autopsies showed that the device stayed in place and remained intact.

Discussion

The new removable transduodenal bypass aims to be a removable therapeutic option for diabetes mellitus type 2 and obesity, replacing previous duodenal lining devices. Use and handling of the device, however, are yet to be tested in the human model in the future.

Advances in endobariatrics: past, present, and future

The obesity epidemic in the USA and worldwide is well documented and continues to grow. Endoscopic metabolic and bariatric therapies may offer a less invasive approach than surgical intervention. This article will review advances in endobariatrics over the last several decades, addressing the past and current state of bariatric and metabolic endoscopy. Food and Drug Administration-cleared devices and interventions currently under investigation are described including gastric devices, gastric remodeling procedures, small-bowel devices, duodenal ablation, as well as procedures to address weight regain after bariatric surgery. Future studies evaluating gastric and duodenal combination therapy, adjunctive pharmacotherapy, as well as individualized precision-health algorithms are underway.

The Role Bariatric Surgery and Endobariatric Therapies in Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Disease spectrum varies from steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved medical therapies, and weight loss through lifestyle modifications remains a mainstay of therapy. Bariatric surgery is the most effective therapy for weight loss and has been shown to improve liver histology. Recently, endoscopic bariatric metabolic therapies have also emerged as effective treatments for patients with obesity and NAFLD. This review summarizes the role of bariatric surgery and endoscopic therapies in the management of patients with NAFLD.

A Comprehensive Review on Bariatric Endoscopy: Where We Are Now and Where We Are Going

Background: Obesity is a chronic disease that impairs quality of life and leads to several comorbidities. When conservative therapies fail, bariatric surgical options such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the most effective therapies to induce persistent weight loss. Over the last two decades, bariatric endoscopy has become a valid alternative to surgery in specific settings. Primary bariatric endoscopic therapies: Restrictive gastric procedures, such as intragastric balloons (IGBs) and endoscopic gastroplasty, have been shown to be effective in inducing weight loss compared to diet modifications alone. Endoscopic gastroplasty is usually superior to IGBs in maintaining weight loss in the long-term period, whereas IGBs have an established role as a bridge-to-surgery approach in severely obese patients. IGBs in a minority of patients could be poorly tolerated and require early removal. More recently, novel endoscopic systems have been developed with the combined purpose of inducing weight loss and improving metabolic conditions. Duodenal mucosal resurfacing demonstrated efficacy in this field in its early trials: significant reduction from baseline of HbA1c values and a modest reduction of body weight were observed. Other endoscopic malabsorptive have been developed but need more evidence. For example, a pivotal trial on duodenojejunal bypasses was stopped due to the high rate of severe adverse events (hepatic abscesses). Optimization of these more recent malabsorptive endoscopic procedures could expand the plethora of bariatric patients that could be treated with the intention of improving their metabolic conditions. Revisional bariatric therapies: Weight regain may occur in up to one third of patients after bariatric surgery. Different endoscopic procedures are currently performed after both RYGB and SG in order to modulate post-surgical anatomy. The application of argon plasma coagulation associated with endoscopic full-thickness suturing systems (APC-TORe) and Re-EndoSleeve have shown to be the most effective endoscopic treatments after RYGB and SG, respectively. Both procedures are usually well tolerated and have a very low risk of stricture. However, APC-TORe may sometimes require more than one session to obtain adequate final results. The aim of this review is to explore all the currently available primary and revisional endoscopic bariatric therapies focusing on their efficacy and safety and their potential application in clinical practice.

What's New in the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem due to its high incidence and consequences. In view of the existing controversies, new therapeutic options for NAFLD are still being sought. Therefore, the aim of our review was to evaluate the recently published studies on the treatment of NAFLD patients. We searched for articles in the PubMed database using appropriate terms, including "non-alcoholic fatty liver disease", "nonalcoholic fatty liver disease", "NAFLD", "diet", "treatment", "physical activity", "supplementation", "surgery", "overture" and "guidelines". One hundred forty-eight randomized clinical trials published from January 2020 to November 2022 were used for the final analysis. The results show significant benefits of NAFLD therapy associated with the use of not only the Mediterranean but also other types of diet (including low-calorie ketogenic, high-protein, anti-inflammatory and whole-grain diets), as well as enrichment with selected food products or supplements. Significant benefits in this group of patients are also associated with moderate aerobic physical training. The available therapeutic options indicate, above all, the usefulness of drugs related to weight reduction, as well as the reduction in insulin resistance or lipids level and drugs with anti-inflammatory or antioxidant properties. The usefulness of therapy with dulaglutide and the combination of tofogliflozin with pioglitazone should be emphasized. Based on the results of the latest research, the authors of this article suggest a revision of the therapeutic recommendations for NAFLD patients.

[Endoscopic treatment for obesity and diabetes]

Obesity and diabetes are associated with increased mortality and morbidity. After failure of conservative therapy such as pharmacotherapy and lifestyle management, bariatric treatment is indicated for selected patients. Endoscopic techniques for weight reduction are well-established treatment for obese population who do not qualify for or are not willing to undergo bariatric surgery. This article is an overview of currently applied endoscopic techniques and summarized current published data.

Duodenal Mucosa: A New Target for the Treatment of Type 2 Diabetes

OBJECTIVE

After a high-fat and high-sugar diet, the duodenal mucosa of rodents proliferate and trigger the signal of insulin resistance, which may be the cause of type 2 diabetes (T2D). In response to this phenomenon, researchers have designed the duodenal mucosal resurfacing (DMR) procedure, mainly through the hydrothermal ablation procedure, to restore the normal mucosal surface, thereby correcting this abnormal metabolic signal. This article aims to understand the changes in duodenum before and after the onset or treatment of T2D, and the potential mechanisms of DMR procedure.

METHODS

A literature search of PubMed and Web of Science was conducted using appropriate keywords.

RESULTS

Both animal and clinical studies have shown that the villus thickness, intestinal cells, glucose transporters, enteric nerves, and gut microbiota and their metabolites in the duodenum undergo corresponding changes before and after the onset or treatment of T2D. These changes may be related to the pathogenesis of T2D. DMR procedure may produce beneficial glycemic and hepatic metabolic effects by regulating these changes.

CONCLUSION

The duodenum is an important metabolic signaling center, and limiting nutrient exposure to this critical region will have powerful metabolic benefits. The DMR procedure may regulate glycemic and hepatic parameters through various mechanisms, which needs to be further confirmed by a large number of animal and clinical studies.

GIE Editorial Board Top 10: advances in GI endoscopy in 2021

The 9-member Editorial Board of the American Society for Gastrointestinal Endoscopy performed a systematic literature search of original articles published during 2021 in Gastrointestinal Endoscopy and 10 other high-impact medical and gastroenterology journals on endoscopy-related topics. Votes from each editorial board member were tallied to identify a consensus list of the 10 most significant topic areas in GI endoscopy over the calendar year of study, with a focus on 3 criteria: significance, novelty, and global impact on clinical practice. The 10 areas identified collectively represent advances in the following endoscopic topics: colonoscopy optimization, bariatric endoscopy, endoscopic needle sampling and drainage, peroral endoscopic myotomy, endoscopic defect closure, meeting systemic challenges in endoscopic training and practice, endohepatology, FNA versus fine-needle biopsy sampling, endoscopic mucosal and submucosal procedures, and cold snare polypectomy. Each board member contributed a summary of important articles relevant to 1 to 2 of the consensus topic areas, leading to a collective summary that is presented in this document of the "top 10" endoscopic advances of 2021.

Duodenal mucosal resurfacing for nonalcoholic fatty liver disease

Content available: Author Interview and Audio Recording.

A Gut-Centric Model of Metabolic Homeostasis

Modern changes in diet and lifestyle have led to an explosion of insulin resistance and metabolic diseases around the globe which, if left unchecked, will become a principal driver of morbidity and mortality in the 21st century. The nature of the metabolic homeostatic shift within the body has therefore become a topic of considerable interest. While the gut has long been recognized as an acute nutrient sensor with signaling mechanisms to the other metabolic organs of the body, its role in regulating the body's metabolic status over longer periods of time has been underappreciated. Recent insights from bariatric surgery and intestinal nutrient stimulation experiments provide a window into the adaptive role of the intestinal mucosa in a foregut/hindgut metabolic balance model that helps to define metabolic parameters within the body-informing the metabolic regulation of insulin resistance versus sensitivity, hunger versus satiety, energy utilization versus energy storage, and protection from hypoglycemia versus protection from hyperglycemia. This intestinal metabolic balance model provides an intellectual framework with which to understand the distinct roles of proximal and distal intestinal segments in metabolic regulation. The model may also aid in the development of novel disease-modifying therapies that can correct the dysregulated metabolic signals from the intestine and stem the tide of metabolic diseases in society.

Endoscopic Bariatric and Metabolic Therapies for Liver Disease: Mechanisms, Benefits, and Associated Risks

Nonalcoholic fatty liver disease (NAFLD), including advanced-stage nonalcoholic steatohepatitis (NASH), is currently the most common chronic liver disease worldwide and is projected to become the leading indication for liver transplantation (LT). However, there are no effective pharmacological therapies for NAFLD. Endoscopic bariatric and metabolic therapies (EBMTs) are less invasive procedures for the treatment of obesity and its metabolic comorbidities. Several recent studies have demonstrated the beneficial effects of EBMTs on NAFLD/NASH. In this review, we summarize the major EBMTs and their mechanisms of action. We further discuss the current evidence on the efficacy and safety of EBMTs in people with NAFLD/NASH and obese cirrhotic LT candidates. The potential utility of EBMTs in reducing liver volume and perioperative complications in bariatric surgery candidates is also discussed. Moreover, we review the development of liver abscesses as a common serious adverse event in duodenal-jejunal bypass liner implantation.

Eliminating exogenous insulin therapy in patients with type 2 diabetes by duodenal ablation and GLP-1RA decreases risk scores for cardiovascular events

Introduction

Duodenal Mucosal Resurfacing (DMR) is an endoscopic ablation technique aimed at improving glycaemia and metabolic health in patients with type 2 diabetes mellitus (T2DM). DMR has an insulin sensitizing effect in patients with T2DM. Reducing hyperinsulinemia can improve cardiovascular health. In the INSPIRE trial, we combined a single DMR with a glucagon-like-peptide-1 receptor agonist (GLP-1RA) and demonstrated elimination of insulin treatment in 69% of patients at 6 months and 53% of patients at 18 months while improving glycaemic control and metabolic health. We hypothesized that this treatment approach is associated with improved cardiovascular health, by reducing hyperinsulinemia.

Methods

Before and 6 months after starting the combination treatment to replace insulin, the following assessments were performed to evaluate cardiovascular health: magnetic resonance imaging (MRI) to measure abdominal visceral adipose tissue volume, ambulatory 24 h blood pressure (ABPM) analysis, postprandial insulin and triglycerides, fasting lipid panel and urine microalbumin. The Atherosclerotic Cardiovascular Disease (ASCVD) score was calculated to estimate 10-year risk of cardiovascular disease or stroke and the diabetes lifetime-perspective prediction (DIAL) score was calculated to estimate years free of cardiovascular disease.

Results

Six months after replacing exogenous insulin by DMR and GLP-1RA, visceral adipose tissue decreased significantly by 24%. Postprandial triglyceride and insulin concentrations decreased significantly (p < 0.001), as did total cholesterol (from median 3.64 (IQR 3.34–4.89) to 3.48 (3.18–3.97) mmol/l, p = 0.008), LDL (from median 1.92 (IQR 1.49–2.30) to 1.79 (1.49–2.08 mmol/l, p = 0.044), and urine microalbumin (from median 7 (IQR 3–27) to 4 (3–8) mg/l, p = 0.018). All daytime blood pressure values decreased significantly. The ASCVD 10-year risk score decreased (from median 13.6 (IQR 5.7–26.0) to 11.5 (4.2–22.5) %, p = 0.030)) and the DIAL score increased (from median 82 (IQR 81–83) to 83 (81–84) years, (p = 0.039)).

Discussion

The combination of DMR and GLP-1RA to replace insulin therapy in patients with T2DM is associated with a positive effect on multiple parameters of cardiovascular health. Taken together, they show a pattern of overall improvement in cardiovascular health, as evidenced by decreased risk scores for cardiovascular complications. However, it is not yet clear whether these improvements will translate into a true reduction in cardiovascular events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01628-z.

Urine Proteome in Distinguishing Hepatic Steatosis in Patients with Metabolic-Associated Fatty Liver Disease

Background: In patients with metabolic-associated fatty liver disease (MAFLD), hepatic steatosis is the first step of diagnosis, and it is a risk predictor that independently predicts insulin resistance, cardiovascular risk, and mortality. Urine biomarkers have the advantage of being less complex, with a lower dynamic range and fewer technical challenges, in comparison to blood biomarkers. Methods: Hepatic steatosis was measured by magnetic resonance imaging (MRI), which measured the proton density fat fraction (MRI-PDFF). Mild hepatic steatosis was defined as MRI-PDFF 5−10% and severe hepatic steatosis was defined as MRI-PDFF > 10%. Results: MAFLD patients with any kidney diseases were excluded. There were 53 proteins identified by mass spectrometry with significantly different expressions among the healthy control, mild steatosis, and severe steatosis patients. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of these significantly changed urinary molecular features correlated with the liver, resulting in the dysregulation of carbohydrate derivative/catabolic/glycosaminoglycan/metabolic processes, insulin-like growth factor receptor levels, inflammatory responses, the PI3K−Akt signaling pathway, and cholesterol metabolism. Urine alpha-1-acid glycoprotein 1 (ORM1) and ceruloplasmin showed the most significant correlation with the clinical parameters of MAFLD status, including liver fat content, fibrosis, ALT, triglycerides, glucose, HOMA-IR, and C-reactive protein. According to ELISA and western blot (30 urine samples, normalized to urine creatinine), ceruloplasmin (ROC 0.78, p = 0.034) and ORM1 (ROC 0.87, p = 0.005) showed moderate diagnostic accuracy in distinguishing mild steatosis from healthy controls. Ceruloplasmin (ROC 0.79, p = 0.028) and ORM1 (ROC 0.81, p = 0.019) also showed moderate diagnostic accuracy in distinguishing severe steatosis from mild steatosis. Conclusions: Ceruloplasmin and ORM1 are potential biomarkers in distinguishing mild and severe steatosis in MAFLD patients.

Endoscopic Bariatric and Metabolic Therapies and Their Effects on Metabolic Syndrome and Non-alcoholic Fatty Liver Disease - A Systematic Review and Meta-Analysis

Background

Endoscopic bariatric and metabolic therapies (EBMTs) are procedures that utilize instruments that require flexible endoscopy or placement of devices for inducing weight loss. We perform a systematic review and meta-analysis to evaluate four modalities – intragastric balloon (IGB), endoscopic sleeve gastroplasty (ESG), duodeno-jejunal bypass liner (DJBL), and duodenal mucosa resurfacing (DMR), for their efficacy and safety on weight loss, non-alcoholic fatty liver disease, and metabolic syndrome.

Methods

Databases MEDLINE via PubMed, and EMBASE are searched and relevant publications up to January 26, 2022 are assessed. Studies are included if they involved human participants diagnosed with obesity and obesity-related comorbid conditions who are treated with any of the 4 EBMTs. IGB and DJBL were chosen as the interventions for the meta-analysis with weight loss (percentage total body weight loss or body mass index) and glycemic control (fasting plasma glucose or HbA1c) as the two main outcomes analyzed.

Results

Six hundred and forty-eight records are reviewed, of which 15 studies are found to be duplicates. Of the 633 records screened, 442 studies are excluded. One hundred and ninety-one articles are assessed for eligibility, for which 171 are excluded. A total of 21 publications are included. Twelve studies are on IGB, two studies on ESG, five studies on DJBL, and two studies on DMR. In these studies with appropriate control, IGB, ESG, and DJBL showed promising benefits on weight loss reduction compared to standard medical therapy (SMT), while DMR appeared to have the least weight reduction benefit. However, the impact on glycemic control featured more prominently in DMR as compared to the rest of the modalities. Different EBMTs have different adverse effect profiles, although device-related adverse events are featured more prominently in DJBL. In the IGB group, there was a significant reduction in 6-month %TBWL [weighted mean difference (WMD) 5.45 (3.88, 7.05)] and FPG WMD −4.89 mg/dL (−7.74, −2.04) compared to the SMT group. There was no significant reduction in BMI between the DJBL and SMT group WMD −2.73 (−5.52, 0.07) kg/m2.

Conclusion

EBMTs have demonstrated a significant impact on weight loss and metabolic comorbidities, and reasonable safety profiles in the studies reviewed. Some data is available to demonstrate reduction of hepatic steatosis, but there is no high-quality data supporting benefits on hepatic lobular inflammation or fibrosis.

Effects of Bariatric Endoscopy on Non-Alcoholic Fatty Liver Disease: A Comprehensive Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Endoscopic bariatric and metabolic therapies (EBMTs) are emerging minimally invasive therapeutic options for obesity and its related complications, including non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the effects of EBMTs on NALFD in patients with obesity.

METHODS

Four databases were searched until Nov 2021. Randomized controlled trials (RCTs) and observational studies reporting liver-related outcomes following Food and Drug Administration (FDA)-approved and non-FDA-approved EBMTs were included. Liver parameters, metabolic parameters, and weight loss were evaluated. Risk of bias was assessed using the "risk of bias" tool in the Cochrane Collaboration for RCTs and the Methodological Index for Non-Randomized Studies criteria for observational studies.

RESULTS

Thirty-three studies with 1710 individuals were included. Regarding the effects of EBMTs on liver fibrosis, a significant decline of NAFLD Fibrosis Score, but not transient elastography-detected liver stiffness or Fibrosis-4 Index, was observed. EBMTs significantly improved liver steatosis (control attenuation parameter and Hepatic Steatosis Index), NAFLD Activity Score, and Homeostasis Model Assessment of Insulin Resistance. EBMTs reduced serum levels of alanine transaminase, aspartate aminotransferase, and gamma-glutamyl transpeptidase considerably. Moreover, EBMTs had reducing effects on the serum levels of triglycerides and total cholesterol as well as body weight.

CONCLUSIONS

Our meta-analysis suggested that EBMTs could ameliorate NAFLD based on the evidence of improved liver steatosis, liver function, and insulin resistance. Large-scale, prospective, long-term studies are warranted to clarify the role of EBMTs in patients with different stages of NAFLD.

Bariatric/Metabolic Surgery

Bariatric surgery is a gastro-intestinal surgery aimed at obtaining weight loss in obesity. The rapid metabolic effects of this type of operations provided a rational to change its name to metabolic surgery, in fact often the improvement of metabolic diseases is observed before a meaningful weight reduction.In this review, we examine the effects of laparoscopic metabolic surgery on life expectancy, type 2 diabetes, hypertension, cardiovascular disease and cancer.Furthermore, we review the surgical endoscopy approaches to obesity including primary obesity procedures and revision procedures that address weight regain after bariatric surgery.Finally, as a bridge to the specific chapter, we summarize the effects on weight reduction of new anti-obesity medications.

Mechanisms of action of duodenal mucosal resurfacing in insulin resistant women with polycystic ovary syndrome

BACKGROUND

Duodenal mucosal resurfacing (DMR) is a novel day-case endoscopic intervention which results in weight loss-independent reductions in HbA1c in patient with type 2 diabetes mellitus (T2DM). We hypothesized that DMR works by increasing insulin sensitivity and we aimed to investigate the mechanism of action of DMR through longitudinal metabolic phenotyping in humans.

METHODS

Thirty-two insulin-resistant women with polycystic ovary syndrome (PCOS) and obesity were randomised in a double-blinded manner to DMR or sham endoscopy. They underwent measurements of insulin sensitivity using euglycaemic hyperinsulinaemic clamps, insulin secretion using oral glucose tolerance tests and reproductive function using weekly reproductive hormone profiles and ovarian ultrasonography for 6 months post-intervention.

RESULTS

A small increase in total body insulin sensitivity measured by the clamp was observed in both groups at week 12. An increase in insulin sensitivity, as measured by HOMA-IR, was observed in both groups at week 24. There was an increase in the number of menses (median 2 DMR, 0.5 sham). There were no significant differences between the two groups in these outcomes or insulin secretion.

CONCLUSIONS

These findings suggest that DMR does not work by increasing insulin sensitivity in euglycaemic, insulin resistant women with PCOS. The procedure may exert its effects only in the context of hyperglycaemia or pathologically hyperplastic, insulin-desensitised duodenal mucosa.

Endoscopic duodenal mucosal resurfacing for nonalcoholic steatohepatitis (NASH): a pilot study

Background and study aims  Nonalcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease worldwide with limited treatment options. Duodenal mucosal resurfacing (DMR) has been associated with improvement in glycaemic parameters and liver function tests (LFTs) in type 2 diabetes. This study aimed to assess the effect of DMR in patients with NASH. Patients and methods  This was a single-center, open-label pilot study. Patients with definite, biopsy-proven NASH (nonalcoholic fatty liver disease activity score [NAS] ≥ 4) underwent a single DMR procedure followed by a 2-week postprocedural diet, without lifestyle intervention. The primary outcome was either resolution of NASH with no worsening of fibrosis or improvement in fibrosis (≥ 1 stage) with no worsening of NASH at 12 months. Secondary outcomes were changes in key histological parameters of NASH, surrogate markers of fibrosis, LFTs, and metabolic factors at 12 months. Results  From 2017 to 2019, 14 patients underwent successful DMR, of whom 11 were included in the analysis. After 12 months, no resolution of NASH was observed, while three patients (27 %) had marginal improvement in fibrosis with no worsening of NASH. Serious adverse events related to the procedure were reported in two patients out of 14 (14 %). Neither weight loss nor improvement in NAS score, or in the other secondary outcomes, were observed at 12 months. Conclusions  In this small and heterogenous study population, we found that DMR, in the absence of lifestyle intervention, did not induce NASH resolution and marginally improved liver fibrosis at 12 months.

Molecular and Cellular Mediators of the Gut-Liver Axis in the Progression of Liver Diseases

The gut-liver axis covers the bidirectional communication between the gut and the liver, and thus includes signals from liver-to-gut (e.g., bile acids, immunoglobulins) and from gut-to-liver (e.g., nutrients, microbiota-derived products, and recirculating bile acids). In a healthy individual, liver homeostasis is tightly controlled by the mostly tolerogenic liver resident macrophages, the Kupffer cells, capturing the gut-derived antigens from the blood circulation. However, disturbances of the gut-liver axis have been associated to the progression of varying chronic liver diseases, such as non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, and primary sclerosing cholangitis. Notably, changes of the gut microbiome, or intestinal dysbiosis, combined with increased intestinal permeability, leads to the translocation of gut-derived bacteria or their metabolites into the portal vein. In the context of concomitant or subsequent liver inflammation, the liver is then infiltrated by responsive immune cells (e.g., monocytes, neutrophils, lymphoid, or dendritic cells), and microbiota-derived products may provoke or exacerbate innate immune responses, hence perpetuating liver inflammation and fibrosis, and potentiating the risks of developing cirrhosis. Similarly, food derived antigens, bile acids, danger-, and pathogen-associated molecular patterns are able to reshape the liver immune microenvironment. Immune cell intracellular signaling components, such as inflammasome activation, toll-like receptor or nucleotide-binding oligomerization domain-like receptors signaling, are potent targets of interest for the modulation of the immune response. This review describes the current understanding of the cellular landscape and molecular pathways involved in the gut-liver axis and implicated in chronic liver disease progression. We also provide an overview of innovative therapeutic approaches and current clinical trials aiming at targeting the gut-liver axis for the treatment of patients with chronic liver and/or intestinal diseases.

Non-alcoholic fatty liver disease: A patient guideline

This patient guideline is intended for all patients at risk of or living with non-alcoholic fatty liver disease (NAFLD). NAFLD is the most frequent chronic liver disease worldwide and comes with a high disease burden. Yet, there is a lot of unawareness. Furthermore, many aspects of the disease are still to be unravelled, which has an important impact on the information that is given (or not) to patients. Its management requires a close interaction between patients and their many healthcare providers. It is important for patients to develop a full understanding of NAFLD in order to enable them to take an active role in their disease management. This guide summarises the current knowledge relevant to NAFLD and its management. It has been developed by patients, patient representatives, clinicians and scientists and is based on current scientific recommendations, intended to support patients in making informed decisions.