Metabolic Effects of Endoscopic Duodenal Mucosal Resurfacing: a Systematic Review and Meta-analysis

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.

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.

Effects of dietary fibre on metabolic health and obesity

Obesity and metabolic syndrome represent a growing epidemic worldwide. Body weight is regulated through complex interactions between hormonal, neural and metabolic pathways and is influenced by numerous environmental factors. Imbalances between energy intake and expenditure can occur due to several factors, including alterations in eating behaviours, abnormal satiation and satiety, and low energy expenditure. The gut microbiota profoundly affects all aspects of energy homeostasis through diverse mechanisms involving effects on mucosal and systemic immune, hormonal and neural systems. The benefits of dietary fibre on metabolism and obesity have been demonstrated through mechanistic studies and clinical trials, but many questions remain as to how different fibres are best utilized in managing obesity. In this Review, we discuss the physiochemical properties of different fibres, current findings on how fibre and the gut microbiota interact to regulate body weight homeostasis, and knowledge gaps related to using dietary fibres as a complementary strategy. Precision medicine approaches that utilize baseline microbiota and clinical characteristics to predict individual responses to fibre supplementation represent a new paradigm with great potential to enhance weight management efficacy, but many challenges remain before these approaches can be fully implemented.

Role of endoscopic duodenojejunal bypass liner in obesity management and glycemic control

The treatment of obesity and its comorbidities ranges from clinical management involving lifestyle changes and medications to bariat-ric and metabolic surgery. Various endoscopic bariatric and metabolic therapies recently emerged to address an important therapeutic gap by offering a less invasive alternative to surgery that is more effective than conservative therapies. This article compre-hensively reviews the technical aspects, mechanism of action, outcomes, and future perspectives of one of the most promising endoscopic bariatric and metabolic therapies, named duodenojejunal bypass liner. The duodenojejunal bypass liner mimics the mechanism of Roux-en-Y gastric bypass by preventing food contact with the duodenum and proximal jejunum, thereby initiating a series of hormonal changes that lead to delayed gastric emptying and malabsorptive effects. These physiological changes result in significant weight loss and improved metabolic control, leading to better glycemic levels, preventing dyslipidemia and non-alcoholic fatty liver disease, and mitigating cardiovascular risk. However, concern ex-ists regarding the safety profile of this device due to the reported high rates of severe adverse events, particularly liver abscesses. Ongo-ing technical changes aiming to reduce adverse events are being evaluated in clinical trials and may provide more reliable data to sup-port its routine use in clinical practice.

Clinical Classification of Obesity and Implications for Metabolic Dysfunction-Associated Fatty Liver Disease and Treatment

Obesity,and metabolic dysfunction-associated fatty liver disease (MAFLD) have reached epidemic proportions globally. Obesity and MAFLD frequently coexist and act synergistically to increase the risk of adverse clinical outcomes (both hepatic and extrahepatic). Type 2 diabetes mellitus (T2DM) is the most important risk factor for rapid progression of steatohepatitis and advanced fibrosis. Conversely, the later stages of MAFLD are associated with an increased risk of T2DM incident. According to the proposed criteria, MAFLD is diagnosed in patients with liver steatosis and in at least one in three: overweight or obese, T2DM, or signs of metabolic dysregulation if they are of normal weight. However, the clinical classification and correlation between obesity and MAFLD is more complex than expected. In addition, treatment for obesity and MAFLD are associated with a reduced risk of T2DM, suggesting that liver-based treatments could reduce the risk of developing T2DM. This review describes the clinical classification of obesity and MAFLD, discusses the clinical features of various types of obesity and MAFLD, emphasizes the role of visceral obesity and insulin resistance (IR) in the development of MAFLD,and summarizes the existing treatments for obesity and MAFLD that reduce the risk of developing T2DM.

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.

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.

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.

[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.

Obesity and type 2 diabetes mellitus: connections in epidemiology, pathogenesis, and treatments

The prevalence of obesity and diabetes mellitus (DM) has been consistently increasing worldwide. Sharing powerful genetic and environmental features in their pathogenesis, obesity amplifies the impact of genetic susceptibility and environmental factors on DM. The ectopic expansion of adipose tissue and excessive accumulation of certain nutrients and metabolites sabotage the metabolic balance via insulin resistance, dysfunctional autophagy, and microbiome-gut-brain axis, further exacerbating the dysregulation of immunometabolism through low-grade systemic inflammation, leading to an accelerated loss of functional β-cells and gradual elevation of blood glucose. Given these intricate connections, most available treatments of obesity and type 2 DM (T2DM) have a mutual effect on each other. For example, anti-obesity drugs can be anti-diabetic to some extent, and some anti-diabetic medicines, in contrast, have been shown to increase body weight, such as insulin. Meanwhile, surgical procedures, especially bariatric surgery, are more effective for both obesity and T2DM. Besides guaranteeing the availability and accessibility of all the available diagnostic and therapeutic tools, more clinical and experimental investigations on the pathogenesis of these two diseases are warranted to improve the efficacy and safety of the available and newly developed treatments.

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.

Duodenal mucosal resurfacing for nonalcoholic fatty liver disease

Content available: Author Interview and Audio Recording.

Novel Endoscopic Bariatric Therapies for the Management of Nonalcoholic Steatohepatitis

Obesity is strongly associated with nonalcoholic fatty liver disease as well as advanced forms of the disease such as nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma. While lifestyle and diet modifications have been the cornerstone of treatment for NASH thus far, they are only effective for less than half of the patients. New endoscopic bariatric therapies (EBTs) have already proved to be safe and effective for the treatment of obesity and type 2 diabetes mellitus, and may provide an intermediate, less invasive, cost-effective option for patients with NASH. In this review, we aim to describe the data and evidence as well as outline future areas of development for endobariatric therapies for the treatment of NASH. In conclusion, EBTs present an effective and safe therapeutic modality for use in the growing pandemic of obesity-related liver disease and should be investigated further with large-scale trials in this patient population.

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.

Future of Metabolic Endoscopy

Obesity has been escalating as one of the worst public health epidemics. Conservative therapies including lifestyle modifications and weight loss medications have limited efficacy and long-term sustainability. Bariatric surgeries, although effective, remain underutilized due to their cost, safety concerns, and patient acceptance. In the past two decades, endoscopic bariatric and metabolic therapies (EBMTs) have emerged as safe, effective, and less invasive options for the treatment of obesity and its comorbidities, with recent studies reporting favorable outcomes in terms of weight loss and metabolic parameters. This article reviews the major and newly developed EBMTs, with emphasis on their metabolic effects and potential use in the management of metabolic conditions.

Primary Bariatric Procedures

Obesity is pandemic. It is estimated that by 2030, half of the U.S. population will have obesity. Current treatment options for obesity includes lifestyle modification, pharmacotherapy, endoscopic bariatric and metabolic therapy (EBMT) and bariatric surgery. Over the past decades, an increasing number of EBMTs have been developed and become available. As a gastroenterologist, it is therefore important to become familiar with the available EBMTs as well as their safety and efficacy profiles in order to educate and expeditiously refer patients for the appropriate therapy when eligible. This chapter will review currently available and upcoming EBMTs. Details on how the procedures are performed, their mechanisms of action as well as data from pivotal studies will be summarized.

Management of Obesity and Nonalcoholic Fatty Liver Disease: A Literature Review

With the recent urbanization and globalization, the adult obesity rate has been increasing, which was paralleled with a dramatic surge in the incidence and prevalence of nonalcoholic fatty liver disease (NAFLD). NAFLD poses a growing threat to human health as it represents the most common cause of chronic liver disease in developed countries. It encompasses a wide spectrum of conditions starting from a build-up of fat in hepatocytes (steatosis), to developing inflammation (steatohepatitis), and reaching up to cirrhosis. It is also associated with higher rates of cardiovascular mortalities. Therefore, proper timely treatment is essential and weight loss remains the cornerstone in the treatment of obesity-related liver diseases. When diet, exercise, and lifestyle changes are not successful, the current recommendation for weight loss includes antiobesity medications and bariatric endoscopic and surgical interventions. These interventions have shown to result in significant weight loss and improve liver steatosis and fibrosis. In the current literature review, we highlight the expected outcomes and side effects of the currently existing options to have a weight-centric NAFLD approach.

Effects of intragastric balloon placement in metabolic dysfunction-associated fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease corresponds to a clinical entity that affects liver function triggered by the accumulation of fat in the liver and is linked with metabolic dysregulation.

AIM

To evaluate the effects of the intragastric balloon (IGB) in patients with metabolic dysfunction-associated fatty liver disease through the assessment of liver enzymes, imaging and several metabolic markers.

METHODS

A comprehensive search was done of multiple electronic databases (MEDLINE, EMBASE, LILACS, Cochrane and Google Scholar) and grey literature from their inception until February 2021. Inclusion criteria involved patients with a body mass index > 25 kg/m² with evidence or previous diagnosis of hepatic steatosis. Outcomes analyzed before and after 6 mo of IGB removal were alanine aminotransferase (IU/L), gamma-glutamyltransferase (IU/L), glycated hemoglobin (%), triglycerides (mg/dL), systolic blood pressure (mmHg), homeostatic model assessment, abdominal circumference (cm), body mass index (kg/m²) and liver volume (cm³).

RESULTS

Ten retrospective cohort studies evaluating a total of 508 patients were included. After 6 mo of IGB placement, this significantly reduced alanine aminotransferase [mean difference (MD): 10.2, 95% confidence interval (CI): 8.12-12.3], gamma-glutamyltransferase (MD: 9.41, 95%CI: 6.94-11.88), glycated hemoglobin (MD: 0.17%, 95%CI: 0.03-0.31), triglycerides (MD: 38.58, 95%CI: 26.65-50.51), systolic pressure (MD: 7.27, 95%CI: 4.79-9.76), homeostatic model assessment (MD: 2.23%, 95%CI: 1.41-3.04), abdominal circumference (MD: 12.12, 95%CI: 9.82-14.41) and body mass index (MD: 5.07, 95%CI: 4.21-5.94).

CONCLUSION

IGB placement showed significant efficacy in improving alanine aminotransferase and gamma-glutamyltransferase levels in patients with metabolic dysfunction-associated fatty liver disease as well as improving metabolic markers related to disease progression.