What is the Mechanism Behind Weight Loss Maintenance with Gastric Bypass?

Safety and Efficacy of Single Anastomosis Sleeve Ileal (SASI) Bypass Surgery on Obese Patients with Type II Diabetes Mellitus during a One-Year Follow-up Period: A Single Center Cohort Study

BACKGROUND

We aimed to evaluate the safety and efficacy of single anastomosis sleeve ileal (SASI) bypass surgery on obese patients with type II diabetes mellitus during a one-year follow-up period.

METHODS

We included patients with a body mass index (BMI) more than 35 kg/m2 and at least one-year history of type II diabetes mellitus. We excluded patients aged under 25 or above 66 years, those who were not candidates for surgery, needed another bariatric surgery, and those not willing to participate in the study. All the patients were visited in the outpatient office on the 10th and 45th days as well as the 3rd month of the post-operative period until the end of the first year.

RESULTS

in this study, we investigated 14 male (23.0%) and 47 female (77.0%) morbidly obese patients with type II diabetes mellitus who underwent SASI bypass. The mean excess weight loss (%EWL) was 60.99±15.69 and the mean total weight loss (%TWL) was 30.39±6.52 at the end of the one-year follow up. Finally, 44 patients (72.1%) had a complete and 15 patients (24.6%) had partial remission of type II diabetes mellitus. Of note, severe complications were recorded in two patients (3.2%). Paired t test analysis demonstrated a significant decrease for fasting plasma sugar (FBS) after one-year follow-up in comparison with FBS before surgery (P<0.0001). Furthermore, this difference was observed in HbA1c (P<0.0001).

CONCLUSION

SASI bypass is an effective method for weight loss and controlling type II diabetes mellitus.

The implication of gut microbiota in recovery from gastrointestinal surgery

Recovery from gastrointestinal (GI) surgery is often interrupted by the unpredictable occurrence of postoperative complications, including infections, anastomotic leak, GI dysmotility, malabsorption, cancer development, and cancer recurrence, in which the implication of gut microbiota is beginning to emerge. Gut microbiota can be imbalanced before surgery due to the underlying disease and its treatment. The immediate preparations for GI surgery, including fasting, mechanical bowel cleaning, and antibiotic intervention, disrupt gut microbiota. Surgical removal of GI segments also perturbs gut microbiota due to GI tract reconstruction and epithelial barrier destruction. In return, the altered gut microbiota contributes to the occurrence of postoperative complications. Therefore, understanding how to balance the gut microbiota during the perioperative period is important for surgeons. We aim to overview the current knowledge to investigate the role of gut microbiota in recovery from GI surgery, focusing on the crosstalk between gut microbiota and host in the pathogenesis of postoperative complications. A comprehensive understanding of the postoperative response of the GI tract to the altered gut microbiota provides valuable cues for surgeons to preserve the beneficial functions and suppress the adverse effects of gut microbiota, which will help to enhance recovery from GI surgery.

Neural signalling of gut mechanosensation in ingestive and digestive processes

Eating and drinking generate sequential mechanosensory signals along the digestive tract. These signals are communicated to the brain for the timely initiation and regulation of diverse ingestive and digestive processes - ranging from appetite control and tactile perception to gut motility, digestive fluid secretion and defecation - that are vital for the proper intake, breakdown and absorption of nutrients and water. Gut mechanosensation has been investigated for over a century as a common pillar of energy, fluid and gastrointestinal homeostasis, and recent discoveries of specific mechanoreceptors, contributing ion channels and the well-defined circuits underlying gut mechanosensation signalling and function have further expanded our understanding of ingestive and digestive processes at the molecular and cellular levels. In this Review, we discuss our current understanding of the generation of mechanosensory signals from the digestive periphery, the neural afferent pathways that relay these signals to the brain and the neural circuit mechanisms that control ingestive and digestive processes, focusing on the four major digestive tract parts: the oral and pharyngeal cavities, oesophagus, stomach and intestines. We also discuss the clinical implications of gut mechanosensation in ingestive and digestive disorders.

Is Revisional Gastric Bypass as Effective as Primary Gastric Bypass for Weight Loss and Improvement of Comorbidities?

BACKGROUND

Revisional gastric bypass (R-RYGB) surgery is utilized for the management of inadequate weight loss or weight regain observed after some cases of bariatric surgeries. Data on the mid-term effectiveness of primary gastric bypass (P-RYGB) compared with R-RYGB (e.g., post sleeve gastrectomy/gastric banding) are controversial.

METHODS

Retrospective chart review of all patients who received P-RYGB and R-RYGB (January 2011-June 2015) at our center. One hundred twenty patients who underwent P-RYGB and 34 R-RYGB who completed 18 months follow-up were included. We compared the effectiveness of P-RYGB with R-RYGB by assessing four anthropometric, two glycemic, and four lipid parameters, as well as the control of type 2 diabetes (T2DM), hypertension, dyslipidemia (remission, improvement, persistence, relapse, de novo), mortality and complications rates.

RESULTS

A comparison of the effectiveness of P-RYGB with R-RYGB at 18 months revealed no significant differences in patients' age, gender, and preoperative BMI between groups. However, patients who received P-RYGB had lower mean weight (P = 0.001) and BMI (P < 0.001), reflected by a higher mean delta BMI (P = 0.02), total weight loss percentage (TWL%) (P < 0.0001) and excess weight loss percentage (EWL%) (P < 0.0001). No differences in glycemic parameters, lipid profiles, control of T2DM, hypertension, and dyslipidemia were observed. No death is reported and complication rates were comparable.

CONCLUSIONS

Although R-RYGB effectively addressed inadequate weight loss, weight regain, and recurrence of comorbidities after restrictive bariatric surgery, R-RYGB resulted in inferior weight loss compared with P-RYGB. Neither procedure differed in their clinical control of T2DM, hypertension, and dyslipidemia. Both procedures exhibited comparable complication rates.

Effects of vitamin D deficiency on the improvement of metabolic disorders in obese mice after vertical sleeve gastrectomy

Vertical sleeve gastrectomy (VSG) is one of the most commonly performed clinical bariatric surgeries for the remission of obesity and diabetes. Its effects include weight loss, improved insulin resistance, and the improvement of hepatic steatosis. Epidemiologic studies demonstrated that vitamin D deficiency (VDD) is associated with many diseases, including obesity. To explore the role of vitamin D in metabolic disorders for patients with obesity after VSG. We established a murine model of diet-induced obesity + VDD, and we performed VSGs to investigate VDD's effects on the improvement of metabolic disorders present in post-VSG obese mice. We observed that in HFD mice, the concentration of VitD3 is four fold of HFD + VDD one. In the post-VSG obese mice, VDD attenuated the improvements of hepatic steatosis, insulin resistance, intestinal inflammation and permeability, the maintenance of weight loss, the reduction of fat loss, and the restoration of intestinal flora that were weakened. Our results suggest that in post-VSG obese mice, maintaining a normal level of vitamin D plays an important role in maintaining the improvement of metabolic disorders.

Weight management strategies for patients with PCOS: current perspectives

INTRODUCTION

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of reproductive-aged women. Overweight and obesity commonly accompany the syndrome at the clinic and are significant concerns for women with PCOS.

AREAS COVERED

Herein, we provide an overview of the relevant literature on weight management strategies in women with PCOS. We performed an electronic-based search using PubMed until February 2021. We aimed to summarize available evidence of different weight-reducing interventions in PCOS and outline the gaps in our current knowledge and recommend areas for further research.

EXPERT OPINION

PCOS is closely linked to obesity and increased adiposity enhances severity and expression of PCOS phenotype. Current data suggest that weight loss is associated with improved metabolic, endocrine, reproductive, cardiovascular and psychological features in overweight and obese women with PCOS. Lifestyle interventions including diet and exercise, anti-obesity medications and bariatric surgery have been used as therapeutic approaches for short-term management of obesity in PCOS with varying success rates. Large and sufficiently powered studies are required in order to determine long-term effects of weight management strategies and potential benefits beyond weight loss in the syndrome. This would allow informing the guidelines to make PCOS specific evidence-based recommendations.

Midterm Outcomes of Gastric Pouch Resizing for Weight Regain After Roux-en-Y Gastric Bypass

PURPOSE

Resizing of the gastric pouch, with eventually resizing of the gastrojejunal anastomosis, has been proposed as revisional procedure to treat weight regain after Roux-en-Y gastric bypass (RYGB), in patients with large gastric pouch and/or large gastrojejunal (GJ) anastomosis. The aim of this study is to determine the midterm results and the safety of laparoscopic resizing of the gastric pouch after RYGB in cases where gastric pouch is > 200 ml and/or GJ anastomosis > 20 mm.

MATERIALS AND METHODS

All patients who underwent gastric pouch resizing between January 2009 and December 2016 were retrospectively reviewed from a prospective database. The gastric pouch was resized to a volume of 30-40 ml.

RESULTS

A total of 48 patients had gastric pouch resizing after RYGB. The mean initial BMI was 42.9 ± 4.8 kg/m². Perioperative morbidity was 8.3% in this series. Mean follow-up was 5.4 years. The mean BMI was 30.0 ± 7.3 kg/m² at 1 year, 30.0 ± 6.0 kg/m² at 3 years, and 30.9 ± 5.7 kg/m² at 5 years. Mean %EBMIL at 1-, 3-, and 5-year follow-up was 51.9%, 55.1%, and 39%, respectively, in 48% follow-up rate. The obesity-related comorbidities disappeared in 67.3% of cases at maximum follow-up.

CONCLUSIONS

In carefully selected patients with gastric pouch size > 200 ml and/or GJ anastomosis > 20 mm, and after extensive preoperative evaluation, gastric pouch resizing is a potentially effective option to treat weight regain due to anatomical factors after RYGB, with complication rate of 8%.

Therapeutic Landscape for NAFLD in 2020

Lifestyle modifications focused on healthy eating and regular exercise are the primary recommendations for patients with nonalcoholic steatohepatitis (NASH). However, for multiple societal, psychological, physical, genetic, and epigenetic reasons, the ability of people to adopt and sustain such changes is challenging and typically not successful. To end the epidemic of NASH and prevent its complications, including cirrhosis and hepatocellular carcinoma, pharmacological interventions are now being evaluated in clinical trials. Treatments include drugs targeting energy intake, energy disposal, lipotoxic liver injury, and the resulting inflammation and fibrogenesis that lead to cirrhosis. It is likely that patients develop the phenotype of NASH by multiple mechanisms, and thus the optimal treatments of NASH will likely evolve to personalized therapy once we understand the mechanistic underpinnings of NASH in each patient. Reviewed here is the treatment landscape in this rapidly evolving field with an emphasis on drugs in Phase 2 and Phase 3 trials.

Influence of post-Roux-en-Y gastric bypass weight recidivism on insulin resistance: a 3-year follow-up

BACKGROUND

Although some early metabolic benefits provided by bariatric surgery are known to occur regardless of weight loss, the impact of mid- to long-term weight recidivism after Roux-en-Y gastric bypass (RYGB) on metabolic outcomes is not profoundly understood.

OBJECTIVE

To investigate the effect of weight recidivism on insulin resistance among nondiabetic individuals with morbid obesity after RYGB during a 3-year follow-up.

SETTING

Public tertiary university hospital.

METHODS

This is a cohort study based on a prospectively collected database of a public tertiary university hospital, which enrolled individuals with morbid obesity who underwent RYGB and were followed-up for 3 years. Weight loss was classified into the following 3 categories: (1) no weight regain; (2) expected regain (regain ≤20% of the maximum weight loss); and (3) obesity recidivism (regain >20% of the maximum weight loss). Homeostasis model assessment (HOMA) values were compared over time.

RESULTS

Of 100 patients, 20% presented obesity recidivism and 52% an expected regain after 3 years of surgery; 28% showed no regain. The recidivism group presented a significant increase in HOMA 3 years after surgery (P = .02). The recidivism group presented a significantly higher HOMA 3 years after surgery than the observed in the other groups (P < .001), as well as a significantly higher percentage of HOMA variation throughout the follow-up (P = .02).

CONCLUSION

Weight recidivism after RYGB was significantly associated with a worsening of insulin resistance among nondiabetic individuals with morbid obesity. Thus, weight loss seems to play a significant role in the maintenance of the early metabolic improvement achieved after RYGB.

Phosphatidylcholine and its relation to apolipoproteins A-1 and B changes after Roux-en-Y gastric bypass: a cohort study

Background

Phosphatidylcholine (PC), the most abundant of the phospholipids, has several metabolic functions in organs such as the liver and the intestine, important structural- and signaling functions in biological membranes, and might have a role in the effects of Roux-en-Y gastric bypass (RYGB), an operation known to ameliorate metabolic diseases, including type 2 diabetes. We hypothesized that serum PC, as a reflection of phospholipid metabolism, changes after RYGB, and that changes are related to weight loss and possibly to changes in glucose metabolism (reflected in the HbA1c-level) as well as to changes in serum Apo A1, Apo B and Apo B/Apo A1 ratio.

Methods

In a cohort of 220 RYGB patients, we studied changes in serum PC after RYGB in relation to serum Apo A1 and Apo B, the main apolipoproteins in HDL- and LDL/VLDL-particles, respectively, up to 2 years following RYGB-surgery.

Results

Serum PC reached its lowest levels 3 months postoperatively to later rebound to preoperative levels 24 months after RYGB. No difference was seen between patients with or without type 2 diabetes. Serum Apo A1 showed a similar pattern whereas serum Apo B concentrations stayed low after the initial decrease after RYGB. As a result, the Apo B / Apo A1 ratio constantly decreased during follow-up. There was a strong positive correlation between PC and Apo A1, and between PC and Apo B, but none between Apo A1 and Apo B. After RYGB surgery, both PC and Apo A1, but not Apo B, correlated positively to weight loss. In relation to total cholesterol, the molar ratio between serum PC and plasma cholesterol increased steadily after RYGB.

Conclusions

We conclude that changes in PC and apolipoproteins after RYGB are highly dynamic, reflecting a large plasticity and capability of accommodating lipid metabolism including PC-, cholesterol- and apolipoprotein metabolism imposed by RYGB surgery, independent of glucose tolerance. We suggest that after RYGB and major weight loss, PC and Apo A1 might have a special role in the altered metabolism of lipoproteins.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1111-7) contains supplementary material, which is available to authorized users.

Care for patients who have undergone one anastomosis gastric bypass surgery

Thousands of bariatric surgery procedures are performed in the UK each year, including gastric bypass surgery. The one anastomosis gastric bypass (OAGB) is increasingly performed in the UK, and nurses may find themselves providing care for patients who have undergone this procedure. This article outlines the anatomical and physiological changes associated with OAGB, routine care of these patients in the short and long term, and the identification and management of complications.

Weight Regain 10 Years After Roux-en-Y Gastric Bypass

OBJECTIVE

This study aims to investigate weight regain and the associated variables 10 years after Roux-en-Y gastric bypass.

METHOD

This retrospective study recruited patients submitted to Roux-en-Y gastric bypass (N = 166) for a 10-year follow-up. The following variables were investigated: body mass index (BMI), percentage of excess weight loss (%EWL), weight regain (WR), and percentage of weight regain (%WG). The chi-squared test or Fisher's exact test compared proportions, and the Mann-Whitney test compared numerical measurements between the groups. Analysis of variance (ANOVA) compared the measurements over time. The significance level was set at 5 %.

RESULTS

The sample had a mean age of 39.59 ± 11.69 years, and females prevailed (71.7 %). In the long-term follow-up, 41 % of the patients had weight regain. Seventy-two months after surgery, excess weight, preoperative BMI, gender, age, nutritional monitoring, and iron deficiency did not explain weight regain. Younger patients had regained significantly more weight 96 (p = 0.008) and 120 months (p = 0.004) after surgery than older patients. Patients who regained weight had ferritin <15 μg/dL 96 months after surgery (p = 0.019).

CONCLUSION

Patients submitted to Roux-en-Y gastric bypass presented weight regain, which increased over time. Age, iron deficiency, and time since surgery were associated with weight regain in the long-term follow-up.

Body Weight Reduction and Biochemical Parameters of the Patients After RYGB and SG Bariatric Procedures in 12-Month Observation

Background

The aim of this study was to evaluate the effect of sleeve gastrectomy (SG) and Roux-en-Y-bypass (RYGB) on anthropometric and biochemical parameters, including changes in glucose levels, lipid profile and liver function. Drastic decrease in all lipid fractions a few weeks or months after the surgery could be regarded as favourable, but low level of HDL is an independent risk factor for heart diseases. Extreme load on the liver without preparation of the patient to the surgery can have negative consequences.

Methods

The test group comprised of 40 female patients at the age of 42.96 with average body weight of 131.56 kg and BMI 46.49. Biochemical analyses were performed using calorimetric method.

Results

No statistically significant differences were observed in glucose levels between the two types of procedures. The highest differences were noted for triglycerides levels, which decreased, as well as all cholesterol fractions, after RYGB, but were increasing during the first months after SG procedure. Changes in lipid profile, caused by the reduction of all lipid fractions, were more visible after RYGB. The decrease in total cholesterol directly and activity of liver enzymes after the procedure was as higher after RYGB as after SG. Increased activity of transaminases indicates significant liver overload.

Conclusions

With the selection of groups of patients with similar initial parameters, it is not clear whether the differences between the two procedures when assessing the improvement of glycaemia are significant. However, due to invasive character of RYGB, liver overload lasting several months and lifelong limited absorption of nutrients, the possibility of SG procedure should be considered as a first option.

Neuroendocrine regulation of energy balance: Implications on the development and surgical treatment of obesity

INTRODUCTION

Obesity, a serious public health problem, occurs mainly when food consumption exceeds energy expenditure. Therefore, energy balance depends on the regulation of the hunger-satiety mechanism, which involves interconnection of the central nervous system and peripheral signals from the adipose tissue, pancreas and gastrointestinal tract, generating responses in short-term food intake and long-term energy balance. Increased body fat alters the gut- and adipose-tissue-derived hormone signaling, which promotes modifications in appetite-regulating hormones, decreasing satiety and increasing hunger senses. With the failure of conventional weight loss interventions (dietary treatment, exercise, drugs and lifestyle modifications), bariatric surgeries are well-accepted tools for the treatment of severe obesity, with long-term and sustained weight loss. Bariatric surgeries may cause weight loss due to restriction/malabsorption of nutrients from the anatomical alteration of the gastrointestinal tract that decreases energy intake, but also by other physiological factors associated with better results of the surgical procedure.

OBJECTIVE

This review discusses the neuroendocrine regulation of energy balance, with description of the predominant hormones and peptides involved in the control of energy balance in obesity and all currently available bariatric surgeries.

CONCLUSIONS

According to the findings of our review, bariatric surgeries promote effective and sustained weight loss not only by reducing calorie intake, but also by precipitating changes in appetite control, satiation and satiety, and physiological changes in gut-, neuro- and adipose-tissue-derived hormone signaling.

Type 2 diabetes mellitus outcomes after laparoscopic gastric bypass in patients with BMI <35 kg/m2 using strict remission criteria: early outcomes of a prospective study among Mexicans

BACKGROUND

Mild obesity (BMI 30-34.9 kg/m²) is highly prevalent worldwide and is associated with type 2 diabetes mellitus. The efficacy of bariatric surgery remains unclear, including among Mexicans. The criteria for diabetes remission are inconsistent, as they are based on different thresholds for glycated hemoglobin, with remission rates ranging from 43 to 73%.

METHODS

Mildly obese patients with type 2 diabetes mellitus who underwent laparoscopic gastric bypass were prospectively analyzed. The primary objective was to determine the impact of surgery on their metabolic profiles. Demographic, clinical, and biochemical parameters were measured at baseline and at 3, 6, 9, 12, and 18 months. Diabetes remission rate was defined as an HbA1c <5.7%. Complications within 30 days and weight loss (% total weight loss) were also analyzed.

RESULTS

Twenty-three Mexican patients underwent surgery. Of the 19 patients, evaluable at 18 months, nine (47.4%) achieved complete diabetes remission, seven (36.8%) showed partial remission, and three (15.8%) showed improvement. Significant improvements in lipid profile, cardiovascular risk, blood pressure, and every metabolic parameter were observed, beginning at the first month and throughout the study. The final total percentage weight loss was 24.9%. Three patients (13%) experienced complications, but none required reoperation or died.

CONCLUSION

Laparoscopic gastric bypass is a safe and effective method to improve the metabolic profile of mildly obese Mexican patients with type 2 diabetes mellitus, inducing high remission rates even when the strictest model is used.

Diarrhea after bariatric procedures: Diagnosis and therapy

Diarrhea after bariatric procedures, mainly those with malabsorptive elements including Roux-Y Gastric Bypass and Biliopancreatic Diversion, is common and an essential determinant of quality of life and micro- and macronutrient deficiencies. Bariatric surgery is the only sustainably successful method to address morbid obesity and its comorbidities, particularly gaining more and more importance in the specific treatment of diabetic patients. Approximately half a million procedures are annually performed around the world, with numbers expected to rise drastically in the near future. A multitude of factors exert their influence on bowel habits; preoperative comorbidities and procedure-related aspects are intertwined with postoperative nutritional habits. Diagnosis may be challenging owing to the characteristics of post-bariatric surgery anatomy with hindered accessibility of excluded segments of the small bowel and restriction at the gastric level. Conventional testing measures, if available, generally yield low accuracy and are usually not validated in this specific population. Limited trials of empiric treatment are a practical alternative and oftentimes an indispensable part of the diagnostic process. This review provides an overview of causes for chronic post-bariatric surgery diarrhea and details the particularities of its diagnosis and treatment in this specific patient population. Topics of current interest such as the impact of gut microbiota and the influence of bile acids on morbid obesity and especially their role in diarrhea are highlighted in order to provide a better understanding of the specific problems and chances of future treatment in post-bariatric surgery patients.

Transoral outlet reduction with full thickness endoscopic suturing for weight regain after gastric bypass: a large multicenter international experience and meta-analysis

BACKGROUND AND AIMS

Many patients who undergo bariatric surgery will experience weight regain and effective strategies are needed to help these patients. A dilated gastrojejunal anastomosis (GJA) has been associated with weight recidivism after Roux-en-Y gastric bypass surgery (RYGB). Endoscopic transoral outlet reduction (TORe) with a full thickness endoscopic suturing device (Overstitch, Apollo Endosurgery, Austin, TX) is a minimally invasive therapeutic option. The primary aim of this project was to examine the safety and long-term efficacy data from three bariatric surgery centers and to conduct a systematic review and meta-analysis of the existing literature.

METHODS

Patients who underwent TORe with the Overstitch device from Jan 2013 to Nov 2016 at 3 participating bariatric surgery centers were included in the multicenter analysis. For the systematic review and meta-analysis, a comprehensive search of multiple English databases was conducted. Random effects model was used.

RESULTS

130 consecutive patients across three centers underwent TORe with an endolumenal suturing device. These patients (mean age 47; mean BMI 36.8) had experienced 24.6% weight regain from nadir weight after RYGB. Average weight lost at 6, 12, and 18 months after TORe was 9.31 ± 6.7 kg (N = 84), 7.75 ± 8.4  kg (N = 70), 8 ± 8.8 kg (N = 46) (p < 0.01 for all three time points), respectively. The meta-analysis included 330 patients. The pooled weight lost at 12 months was 8.4 kg (95% CI 6.5-10.3) with no significant heterogeneity across included studies (p = 0.07). Overall, 14% of patients experienced nausea, 18% had pain and 8% required a repeat EGD. No serious adverse events reported.

CONCLUSION

When implemented as part of a multidisciplinary intervention, TORe using endolumenal suturing is safe, reproducible, and effective approach to manage weight recidivism after RYGB and should be utilized early in the management algorithm of these patients.

Metabolic and Bariatric Surgery for Obesity

Metabolic and bariatric surgery (MBS) leads to weight loss in obese individuals and reduces comorbidities such as type 2 diabetes. MBS is superior to medical therapy in reducing hyperglycemia in persons with type 2 diabetes, and has been associated with reduced mortality and incidences of cardiovascular events and cancer in obese individuals. New guidelines have been proposed for the use of MBS in persons with type 2 diabetes. We review the use of MBS as a treatment for obesity and obesity-related conditions and, based on recent evidence, propose that health care systems make the appropriate changes to increase accessibility for eligible patients.

The gut microbiota and gastrointestinal surgery

Surgery involving the gastrointestinal tract continues to prove challenging because of the persistence of unpredictable complications such as anastomotic leakage and life-threatening infections. Removal of diseased intestinal segments results in substantial catabolic stress and might require complex reconstructive surgery to maintain the functional continuity of the intestinal tract. As gastrointestinal surgery necessarily involves a breach of an epithelial barrier colonized by microorganisms, preoperative intestinal antisepsis is used to reduce infection-related complications. The current approach to intestinal antisepsis varies widely across institutions and countries with little understanding of its mechanism of action, effect on the gut microbiota and overall efficacy. Many of the current approaches to intestinal antisepsis before gastrointestinal surgery run counter to emerging concepts of intestinal microbiota contributing to immune function and recovery from injury. Here, we review evidence outlining the role of gut microbiota in recovery from gastrointestinal surgery, particularly in the development of infections and anastomotic leak. To make surgery safer and further reduce complications, a molecular, genetic and functional understanding of the response of the gastrointestinal tract to alterations in its microbiota is needed. Methods can then be developed to preserve the health-promoting functions of the microbiota while at the same time suppressing their harmful effects.

The Surgical Management of Obesity

In the United States, more than one-third of the population is obese. Currently, bariatric surgery is the best known treatment for obesity, and multiple meta-analyses have shown bariatric surgery to be more effective for treating obesity than diet and exercise or pharmacologic treatment. The modern era of bariatric surgery began in 2005, which is defined by a drastic increase in the use of laparoscopy. Bariatric surgery has the potential to improve obesity-related comorbidities, such as type 2 diabetes, cardiovascular disease, and sleep apnea. The effect of bariatric surgery on weight loss and comorbidities varies by the type of procedure.

[Evolution of type 2 diabetes and carbohydrate intolerance following bariatric surgery in a Mexican mestizo population]

BACKGROUND

Bariatric surgery continues to be the best treatment for weight loss and control of obesity related comorbidities. Gastric bypass and sleeve gastrectomy have demonstrated to be the most effective surgeries, but this has not been established in a Mexican (non-American) population.

OBJECTIVE

To analyse the improvement in type 2 diabetes mellitus and carbohydrate intolerance in obese patients after bariatric surgery.

MATERIAL AND METHODS

A retrospective analysis was performed on the data collected prospectively between 2013 and 2015 on every obese patient with diabetes and carbohydrate intolerance submitted for bariatric surgery. Analysis was performed at baseline, and at 1, 3, 6, 9 and 12 months, and included metabolic, clinical, lipid, and anthropometrical parameters. A peri-operative and morbidity and mortality analysis was also performed. Remission rates for patients with diabetes were also established.

RESULTS

The analysis included 73 patients, 46 with diabetes and 27 with carbohydrate intolerance. Sixty-two patients were female with a mean age of 42 years. Baseline glucose and glycosylated haemoglobin were 123±34mg/dl and 6.8±1.6%, and at 12 months they were 90.1±8mg/dl and 5.4±0.3%, respectively. Diabetes remission was observed in 68.7% of patients, including 9.3% with partial remission and 21.8% with an improvement. There was also a significant improvement in all metabolic and non-metabolic parameters.

CONCLUSIONS

Bariatric surgery safely improves the metabolic status of patients with diabetes mellitus or carbohydrate intolerance during the first year, inducing high rates of complete remission. It has also shown a significant improvement on blood pressure, lipid, and anthropometric parameters during the first year of follow-up.

Vertical sleeve gastrectomy activates GPBAR-1/TGR5 to sustain weight loss, improve fatty liver, and remit insulin resistance in mice

Vertical sleeve gastrectomy (VSG) is one of the most commonly performed clinical bariatric surgeries used for the remission of obesity and diabetes. However, the precise molecular mechanism by which VSG exerts its beneficial effects remains elusive. We report that the membrane-bound G protein-coupled bile acid receptor, GPBAR-1 (also known as TGR5), is required to mediate the effects of anti-obesity, anti-hyperglycemia, and improvements of fatty liver of VSG in mice. In the absence of TGR5, the beneficial metabolic effects of VSG in mice are lost. Moreover, we found that the expression of TGR5 increased significantly after VSG, and VSG alters both BA levels and composition in mice, resulting in enhancement of TGR5 signaling in the ileum and brown adipose tissues, concomitant with improved glucose control and increased energy expenditure.

CONCLUSION

Our study elucidates a novel underlying mechanism by which VSG achieves its postoperative therapeutic effects through enhanced TGR5 signaling. (Hepatology 2016;64:760-773).

Microbial perturbations and modulation in conditions associated with malnutrition and malabsorption

The intestinal microbiota is a complex ecosystem, which can be considered an accessory organ. It involves complex microbe-microbe and host-microbe interactions with indispensable functions for the human host with regard to the intestinal epithelium and barrier function, the innate and adaptive immune system, and its large metabolic capacity. Saccharolytic fermentation results in the production of short chain fatty acids, which exert an array of beneficial effects, while proteolytic fermentation leads to an increase in potentially harmful metabolites. In addition, numerous other microbial metabolites are being produced with various intestinal as well as extra-intestinal effects. Their generation depends on the composition of the microbiota as well as the availability of substrates, which both vary along the GI tract. Diet impacts the intestinal microbiota composition and activity in early infancy as well as in adults. Microbial perturbations have been demonstrated in subjects with under-nutrition and/or malabsorption. The bidirectional interactions between the microbiome, nutrient availability and GI function, can contribute to a vicious circle, further impairing health outcome in conditions associated with malnutrition and/or malabsorption. Integrated multivariate approaches are needed to further unravel the complex interaction between microbiome, diet and host factors, as well as possible modulation thereof by prebiotics or probiotics. The present overview will briefly outline the composition and function of the intestinal microbiota, its association with nutrient intake and availability, and will address the role of the intestinal microbiota in malnutrition and malabsorption.