The risk of inflammatory bowel disease after bariatric surgery

Gut microbiome shifts in adolescents after sleeve gastrectomy with increased oral-associated taxa and pro-inflammatory potential

Bariatric surgery is highly effective in achieving weight loss in children and adolescents with severe obesity, however the underlying mechanisms are incompletely understood, and gut microbiome changes are unknown. Here, we show that adolescents exhibit significant gut microbiome and metabolome shifts several months after laparoscopic vertical sleeve gastrectomy (VSG), with increased alpha diversity and notably with enrichment of oral-associated taxa. To assess causality of the microbiome/metabolome changes in phenotype, pre-VSG and post-VSG stool was transplanted into germ-free mice. Post-VSG stool was not associated with any beneficial outcomes such as adiposity reduction compared pre-VSG stool. However, post-VSG stool exhibited a potentially inflammatory phenotype with increased intestinal Th17 and decreased regulatory T cells. Concomitantly, we found elevated fecal calprotectin and an enrichment of proinflammatory pathways in a subset of adolescents post-VSG. We show that in some adolescents, microbiome changes post-VSG may have inflammatory potential, which may be of importance considering the increased incidence of inflammatory bowel disease post-VSG.

Severe obesity, a susceptibility factor for developing inflammatory bowel disease: results of a population-based study

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) develops in genetically susceptible individuals exposed to certain environmental factors, of which only a few have been established. We aimed to assess whether bariatric surgery (BS) and severe obesity are associated with an increased risk of developing IBD.

METHODS

Adults diagnosed with obesity or severe obesity between 2005 and 2020 were identified from the Catalan Health Surveillance System; those diagnosed with IBD prior to the diagnosis of obesity or severe obesity were excluded. Individuals who had undergone BS and those with a new diagnosis of IBD were identified and their likelihood of developing IBD was analyzed.

RESULTS

A total of 93 473 individuals with severe obesity, 1 009 256 with obesity and 14 698 who underwent BS were identified. The incidence rates of IBD among individuals who had undergone BS prior to IBD diagnosis was 0.84 cases per 1000 person-years, 0.90 cases per 1000 person-years among individuals with severe obesity without BS and 0.60 cases per 1000 person-years in individuals with obesity. In the multivariable regression analysis, severe obesity (hazard ratio [HR] 1.46; 95% confidence interval [95%CI] 1.31-1.62), BS (HR 1.57; 95%CI 1.25-1.97), and smoking habit (HR 1.57; 95%CI 1.46-1.69) were risk factors for developing IBD (as well as for Crohn's disease and ulcerative colitis).

CONCLUSIONS

Severe obesity and BS were independent risk factors for the development of IBD. noninvasive screening for IBD seems to be warranted in this population.

Outcomes of Metabolic and Bariatric Surgery in Patients with Inflammatory Bowel Disease: A Long-Term Retrospective Analysis

Background: Metabolic and bariatric surgery (MBS) is a well-established treatment for severe obesity, yet its effects in patients with inflammatory bowel disease (IBD) are not well understood. MBS in this population presents unique challenges, including the potential for exacerbating inflammatory disease activity and causing complications such as malnutrition and medication malabsorption. This study aims to assess the long-term outcomes of MBS in IBD patients, focusing on both metabolic outcomes and its impact on the course of IBD. Methods: A retrospective analysis was conducted on 20 patients with IBD who underwent MBS at a tertiary center between 2005 and 2019. Data on baseline characteristics, surgical procedures, complications, weight loss, resolution of obesity-related diseases, and IBD-related outcomes were collected. Results: The cohort, primarily female (65%), had a mean preoperative body mass index (BMI) of 40.8 kg/m2. The MBS procedures performed were sleeve gastrectomy (n = 9), Roux-en-Y gastric bypass (n = 6), one-anastomosis gastric bypass (n = 2), and Laparoscopic Adjustable Gastric Banding (n = 3). No major 30-day complications were recorded. At a median follow-up of 91 months, the mean BMI decreased by 9.5 kg/m2, with satisfactory outcomes in terms of resolution of obesity-related diseases. IBD activity scores increased postoperatively, particularly in Crohn's disease (CD) patients, although these changes were not statistically significant. In addition, 30% of patients were hospitalized due to IBD exacerbation, and 15% required surgical intervention for IBD. Conclusions: MBS is an effective treatment for severe obesity and its related diseases in IBD patients. While encountering no major complications or mortality, some long-term complications were observed, with a possible increase in IBD activity, particularly in CD patients. Ongoing challenges, such as the risk of malnutrition, medication malabsorption, and postoperative IBD exacerbations, necessitate careful long-term follow-up.

Reversal of Roux-en-Y Gastric Bypass to Normal Anatomy in a Severely Malnourished Patient After Metabolic Bariatric Surgery

Obesity stands as a prominent health challenge in our society, with metabolic bariatric surgery (MBS) emerging as a solution due to its efficacy in addressing obesity-related type 2 diabetes mellitus (T2DM). Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB) remain the most common MBS after sleeve gastrectomy. Complications from RYGB are uncommon but include anastomotic stricture, marginal ulcers, small bowel obstruction, and nutritional complications. We present a 52-year-old lady with an initial body mass index (BMI) of 27.6 kg/m2 and poorly controlled T2DM who presented with generalized body weakness and uncontrolled weight loss after an RYGB performed four months earlier. She was cachexic with a BMI of 17 kg/m2,with generalized anasarca with a multitude of electrolyte disturbances. After nutritional optimization, she underwent a reversal surgery back to normal anatomy. Reversal of RYGB to normal anatomy is a complex surgical procedure and is often the last resort undertaken in patients experiencing severe complications from the initial surgery. Indications include malnutrition, severe dumping syndrome, excessive weight loss, and recalcitrant marginal ulcers. Our case outlines the importance of proper patient selection for MBS and highlights the preoperative management of RYGB reversal to normal anatomy. We also describe the surgical procedure using a stepwise approach. In conclusion, the reversal of RYGB to normal anatomy should only be undertaken after a careful period of prehabilitation to reduce perioperative complications. The inclusion of dietitians, endocrinologists, and physiotherapists is crucial to ensure the best possible outcome.

The Impact of Gastrectomy on Inflammatory Bowel Disease Risk in Gastric Cancer Patients: A Critical Analysis

Gastrectomy, a prevalent surgical procedure for gastric cancer, results in substantial alterations to the gastrointestinal tract, including reduced gastric acid production and significant modifications to the gut microbiota. These changes can impair postoperative recovery, influence metabolic functions, and predispose patients to inflammatory bowel disease (IBD). Studies have shown an increased risk of IBD, particularly Crohn's disease (CD) and ulcerative colitis (UC), in patients following gastrectomy and bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). For instance, patients undergoing RYGB have a higher hazard ratio for developing CD, while SG patients show an increased risk for UC. The surgical alteration of the gastrointestinal tract promotes dysbiosis, with a significant increase in pathogenic bacteria and a decrease in beneficial microbial populations. This dysbiosis can impair the intestinal mucosal barrier and promote systemic inflammation. Understanding the mechanisms behind these changes and their clinical implications is essential for developing effective postoperative management strategies. Probiotics and enhanced recovery after surgery (ERAS) protocols have shown promise in mitigating these adverse effects, improving gut microbiota balance, and enhancing patient outcomes. Further research is necessary to fully elucidate the long-term impacts of gastrectomy on gastrointestinal health and to refine therapeutic approaches for postoperative care.

Gut microbiome shifts in adolescents after sleeve gastrectomy with increased oral-associated taxa and pro-inflammatory potential

Background

Bariatric surgery is highly effective in achieving weight loss in children and adolescents with severe obesity, however the underlying mechanisms are incompletely understood, and gut microbiome changes are unknown.

Objectives

1) To comprehensively examine gut microbiome and metabolome changes after laparoscopic vertical sleeve gastrectomy (VSG) in adolescents and 2) to assess whether the microbiome/metabolome changes observed with VSG influence phenotype using germ-free murine models.

Design

1) A longitudinal observational study in adolescents undergoing VSG with serial stool samples undergoing shotgun metagenomic microbiome sequencing and metabolomics (polar metabolites, bile acids and short chain fatty acids) and 2) a human-to-mouse fecal transplant study.

Results

We show adolescents exhibit significant gut microbiome and metabolome shifts several months after VSG, with increased alpha diversity and notably with enrichment of oral-associated taxa. To assess causality of the microbiome/metabolome changes in phenotype, pre-VSG and post-VSG stool was transplanted into germ-free mice. Post-VSG stool was not associated with any beneficial outcomes such as adiposity reduction compared pre-VSG stool. However, post-VSG stool exhibited an inflammatory phenotype with increased intestinal Th17 and decreased regulatory T cells. Concomitantly, we found elevated fecal calprotectin and an enrichment of proinflammatory pathways in a subset of adolescents post-VSG.

Conclusion

We show that in some adolescents, microbiome changes post-VSG may have inflammatory potential, which may be of importance considering the increased incidence of inflammatory bowel disease post-VSG.

New Onset Inflammatory Bowel Disease Risk Following Bariatric Surgery: A Systematic Review and Meta-Analysis of Observational Studies

Background: While bariatric surgery may reduce obesity-associated inflammation, alterations in gut microbiome and nutrition could impact inflammatory bowel disease (IBD) risk. This study aimed to investigate the association between bariatric surgery and new onset IBD. Methods: A systematic review and meta-analysis of observational studies was conducted from inception to 31 January 2024. Risk estimates were pooled using a DerSimonian and Laird random-effects model, and adjusted hazards ratios (HRs) with corresponding 95% confidence interval (CI) were reported. The modified Newcastle-Ottawa Quality Assessment Scale (NOS) was used to examine the risk of bias. Results: Of 98 articles screened, four studies comprising 4,727,600 participants were included in the systematic review and two studies in the meta-analysis. Included studies had high quality and low risk of bias according to NOS. The pooled analysis revealed a significant risk of new onset IBD (HR: 1.28, 95% CI: 1.04–1.53, I2 = 74.9%), particularly Crohn’s disease (HR: 1.75, 1.59–1.92, I2 = 0), following bariatric surgery, but no significant risk of ulcerative colitis (HR: 0.93, 0.75–1.11, I2 = 11.5%). Conclusions: This meta-analysis found that bariatric surgery was associated with a higher risk of developing Crohn’s disease. Patients should be counseled on IBD risk pre-surgery, and symptomatic patients should be evaluated post-surgery to enable early diagnosis and management.

Alterations in bile acid kinetics after bariatric surgery in patients with obesity with or without type 2 diabetes

BACKGROUND

Bariatric surgery is an effective treatment option for obesity and provides long-term weight loss and positive effects on metabolism, but the underlying mechanisms are poorly understood. Alterations in bile acid metabolism have been suggested as a potential contributing factor, but comprehensive studies in humans are lacking.

METHODS

In this study, we analysed the postprandial responses of bile acids, C4 and FGF19 in plasma, and excretion of bile acids in faeces, before and after bariatric surgery in patients (n = 38; 74% females) with obesity with or without type 2 diabetes from the BARIA cohort.

FINDINGS

We observed that total fasting plasma bile acid levels increased, and faecal excretion of bile acids decreased after surgery suggesting increased reabsorption of bile acids. Consistent with increased bile acid levels after surgery we observed increased postprandial levels of FGF19 and suppression of the bile acid synthesis marker C4, suggesting increased FXR activation in the gut. We also noted that a subset of bile acids had altered postprandial responses before and after surgery. Finally, fasting plasma levels of 6α-hydroxylated bile acids, which are TGR5 agonists and associated with improved glucose metabolism, were increased after surgery and one of them, HDCA, covaried with diabetes remission in an independent cohort.

INTERPRETATION

Our findings provide new insights regarding bile acid kinetics and suggest that bariatric surgery in humans alters bile acid profiles leading to activation of FXR and TGR5, which may contribute to weight loss, improvements in glucose metabolism, and diabetes remission.

FUNDING

Novo Nordisk Fonden, Leducq Foundation, Swedish Heart-Lung Foundation, Knut and Alice Wallenberg Foundation, the ALF-agreement, ZonMw.

Effect of Bariatric Surgery on Disease Outcomes in Patients With Inflammatory Bowel Disease: A US-based Propensity Matched Cohort Study

INTRODUCTION AND AIM

A growing body of evidence suggests a negative impact of obesity on the disease activity of inflammatory bowel disease (IBD). The primary aim of the study was to evaluate disease outcomes of IBD in patients after bariatric surgery (BS).

METHODS

Patients with IBD and morbid obesity who underwent BS were compared with patients with IBD and morbid obesity without BS in a retrospective, propensity-score matched cohort study using TriNetX, a multi-institutional database. The primary aim was to assess the 2-year risk of a composite of disease-related complications, which included intravenous steroid use or IBD-related surgery. Risk was expressed as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

RESULTS

In all, 482 patients (3.4%) with IBD and morbid obesity underwent BS (mean age 46.9±11.2 y old, mean BMI 42.1±7.72 kg/m 2 , Crohn's disease 60%). After propensity-score matching, the BS cohort had a lower risk (aOR 0.31, 95% CI 0.17-0.56) of a composite of IBD-related complications compared with the control cohort. After propensity-score matching, the BS cohort with sleeve gastrectomy had a decreased risk (aOR 0.45, 95% CI 0.31-0.66) of a composite of IBD-related complications. There was no difference in the risk (aOR 0.77, 95% CI 0.45-1.31) of a composite of IBD-related complications between the BS cohort with Roux-en-Y gastric bypass (RYGB) compared with the control cohort.

CONCLUSION

Sleeve gastrectomy but not Roux-en-Y gastric bypass is associated with improved disease-specific outcomes in patients with IBD and morbid obesity.

The Role of Endoscopy in the Management of Adolescent Bariatric Patients: A Primer For Pediatric Gastroenterologists

PURPOSE OF REVIEW

The prevalence of childhood and adolescent obesity in the United States has reached alarming levels, necessitating effective interventions such as bariatric surgery. This article reviews the current state of bariatric surgery in the adolescent population, highlighting the common complications encountered in post-bariatric patients. Furthermore, it outlines the pivotal role of endoscopy in both the prevention and management of these bariatric complications.

RECENT FINDINGS

Though only a minority of eligible adolescent patients undergo bariatric surgery the number of cases continues to increase. Sleeve gastrectomy has emerged as the preferred type of surgery, with the best balance of safety and efficacy. However, only a small number of pediatric surgeons have additional bariatric training and a number of technical aspects of the surgery itself impact the risk for post-surgical complications. Gastric sleeve stenosis, anastomotic leaks and gastroesophageal reflux are the most common of these complications. Ability to perform dilation of sleeve stenosis, closure of anastomotic leaks and evaluation of reflux are critical tools in the endoscopic toolbox necessary for the management of these complicated patients. Bariatric surgery remains the most effective treatment available for management of morbid obesity in adolescents but has significant associated complications. Pediatric gastroenterologists must be familiar in the endoscopic management of these complications and are crucial in creating a high functioning adolescent bariatric program.

Bariatric Surgery and Inflammatory Bowel Disease: National Trends and Outcomes Associated with Procedural Sleeve Gastrectomy vs Historical Bariatric Surgery Among US Hospitalized Patients 2009-2020

PURPOSE

The association between bariatric surgery and IBD-related inpatient outcomes is not well characterized. We report, analyze, and compare inpatient trends and outcomes among encounters with a history of bariatric surgery (Hx-MBS) compared to those receiving bariatric surgery during index admission (PR-MBS) admitted from 2009 to 2020.

METHODS

Retrospective cohort design: the 2009-2020 National Inpatient Sample (NIS) databases were used to identify hospital encounters with patients aged ≥ 18 years with a history of MBS (Hx-MBS) or with procedure coding indicating MBS procedure (PR-MBS) according to International Classification of Diseases, Ninth (ICD-9-CM/ ICD-9-PCS) or Tenth Revision (ICD-10-CM/ICD-10-PCS) Clinical Modification/Procedure Coding System during index admission (ICD-9-CM: V4586; ICD-10-CM: Z9884; ICD-9-PR: 4382, 4389; ICD-10-PR: 0DB64Z3, 0DB63ZZ). Pearson χ2 analysis, analysis of variance, multivariable regression analyses, and propensity matching on independent variables were conducted to analyze significant associations between variables and for primary outcome inflammatory bowel disease-related admission, and secondary outcomes: diagnosis of nonalcoholic steatohepatitis, nonalcoholic fatty liver disease, or chronic mesenteric ischemia during admission.

RESULTS

We identified 3,365,784 (76.20%) Hx-MBS hospitalizations and 1,050,900 hospitalizations with PR-MBS (23.80%). Propensity score matching analysis demonstrated significantly higher odds of inflammatory bowel disease, and chronic mesenteric ischemia for Hx-MBS compared to PR-MBS, and significantly lower odds of nonalcoholic steatohepatitis and nonalcoholic fatty liver disease for Hx-MBS compared to PR-MBS.

CONCLUSION

In our study, Hx-MBS was associated with significantly increased odds of inflammatory bowel disease and other GI pathologies compared to matched controls. The mechanism by which this occurs is unclear. Additional studies are needed to examine these findings.

Outcomes of bariatric surgery for patients with prevalent inflammatory bowel disease: A nationwide registry-based cohort study

BACKGROUND

Obesity is becoming more prevalent in patients with inflammatory bowel disease. Although bariatric surgery is an effective treatment for obesity, questions remain regarding its safety and effectiveness for patients with inflammatory bowel disease. The aim of this study was to evaluate the safety and effectiveness of bariatric surgery in patients with inflammatory bowel disease.

METHOD

This registry-based, propensity-matched cohort study included all patients who had primary Roux-en-Y gastric bypass or sleeve gastrectomy in Sweden from January 2007 to June 2020 who had an inflammatory bowel disease diagnosis and matched control patients without an inflammatory bowel disease diagnosis. The study included data from the Scandinavian Obesity Surgery Registry, the National Patient Register, the Swedish Prescribed Drugs Register, the Total Population Register, and the Education Register from Statistics Sweden.

RESULTS

In total, 71,093 patients who underwent bariatric surgery, including 194 with Crohn's disease and 306 with ulcerative colitis, were 1:5 matched to non-inflammatory bowel disease control patients. The patients with Crohn's disease had a higher readmission rate within 30 days (10.7% vs 6.1%, odds ratio = 1.84, 95% confidence interval 1.02-3.31) than the control patients, with no significant difference between the surgical methods. The patients with ulcerative colitis had a higher risk for serious postoperative complications after Roux-en-Y gastric bypass (8.0% vs 3.7%, odds ratio = 2.64, 95% confidence interval 1.15-6.05) but not after sleeve gastrectomy compared to control patients (0.8% vs 2.3%). No difference was observed in postoperative weight loss or postoperative health-related quality of life.

CONCLUSION

Sleeve gastrectomy appears to be a safe and effective treatment for obesity in patients with inflammatory bowel disease, whereas Roux-en-Y gastric bypass was associated with a higher risk for postoperative complications in patients with ulcerative colitis.

De Novo Inflammatory Bowel Disease Following Bariatric Surgery: a Systematic Review and Meta-analysis

The incidence of both obesity and inflammatory bowel disease (IBD) is rising globally. The influence of bariatric metabolic surgery (BMS) upon IBD development is largely unknown. This systematic review and meta-analysis aimed to evaluate the relationship between BMS and the risk of de novo IBD development following surgery. A systematic literature search and meta-analysis were performed using PubMed and Scopus databases. Inclusion criteria were any study reporting risk of de novo IBD development following BMS relative to an appropriate control cohort. Pooled odds ratios (POR) were calculated. A total of 31 articles were identified by the literature search. Four studies including 149,385 patients met the inclusion criteria and were included in the meta-analysis. Pooled estimation of a meta-analysis of risk ratios studies demonstrated a POR for the development of IBD following BMS of 1.17 (95% CI, 1.06-1.29). This indicates a 17% increase in relative risk of de novo IBD development for those patients receiving BMS compared to those treated by non-surgical methods. Based on the present data, there appears to be an association between BMS and risk of de novo IBD. Compared to the proven benefits of BMS on other aspects of patient health, this potential risk remains proportionally low but may be an important consideration for patients both pre- and post-operatively.