Changes in Gut Microbiota and Hormones After Bariatric Surgery: a Bench-to-Bedside Review

The relationship between oxidative stress markers and temporomandibular disorders: A systematic review and meta-analysis

Background

Oxidative stress has a role in many pathologic conditions, including oral diseases and temporomandibular joint disorders (TMDs) pathophysiology. This study compared the selected oxidative biomarkers' levels in TMD patients and healthy controls in a systematic review and meta-analysis.

Materials and Methods

Medline/PubMed, Scopus, Web of Science, Google Scholar, and Embase were systematically searched for English articles up to October 2022 using MeSH and free keywords. Joanna Briggs Institute checklist was used to assess the risk of bias. Differences between biomarker levels in TMD patients were compared to the control group.

Results

Ten case-control studies were included based on inclusion and exclusion criteria with a total of 659 patients: 314 with TMD and 345 healthy controls. The studies investigated 15 markers, including total oxidant status (TOS), total antioxidant status, and malondialdehyde (MDA). There was a significant difference in the salivary MDA of patients with TMD in comparison with healthy people; standard mean difference = 3.22 (95% confidence interval [CI]: 0.28-6.16); I 2 = 96.0%). The Antioxidant status in serum was significantly lower in patients with TMD in comparison with healthy people; weighted mean difference = -0.52 (95% CI: -0.90 to -0.14; I 2 = 97.0%). The result of TOS was inconclusive.

Conclusion

Salivary MDA and serum total antioxidative status measurements may be used as a biomarker for diagnosing TMD. Due to the lack of sufficient evidence, it is not possible to express a definite relation between the amount and type of marker and TMD diagnosis, which suggests that more case-control studies with larger sample sizes are required.

Relationships Between Changes in Serum Ketone Body Levels and Metabolic Effects in Patients with Severe Obesity Who Underwent Laparoscopic Sleeve Gastrectomy

BACKGROUND

Serum ketone bodies increase due to dynamic changes in the lipid metabolisms of patients undergoing bariatric surgery. However, there have been few studies on the role of ketone bodies after bariatric surgery. We aimed to clarify the role of and relationship between the changes in serum ketone bodies and weight loss, as well as between those changes and the metabolic effects after laparoscopic sleeve gastrectomy (LSG).

METHODS

We recruited 52 patients with severe obesity who underwent LSG. We measured acetoacetic acid (AcAc) and β-hydroxybutyric acid (β-OHB) at the baseline, 1 month, and 6 months after LSG. Subsequently, we compared the changes in the serum ketone bodies with weight-loss effects and various metabolic parameters.

RESULTS

At 1 month after LSG, β-OHB significantly increased (p = 0.009), then significantly decreased 6 months after LSG (p = 0.002). In addition, β-OHB in patients without Type 2 diabetes (T2D) and metabolic dysfunction-associated steatohepatitis (MASH) was notably higher than in patients with T2D at 1 month after LSG (p < 0.001). In the early phase, both AcAc and β-OHB mainly had strong positive correlations with changes in T2D- and MASH-related parameters. In the middle term after LSG, changes in both AcAc and β-OHB were positively correlated with changes in lipid parameters and chronic kidney disease-related parameters.

CONCLUSION

We demonstrated that the postoperative surge of ketone bodies plays a crucial function in controlling metabolic effects after LSG. These findings suggest the cause- and consequence-related roles of ketone bodies in the metabolic benefits of bariatric surgery.

Irritable bowel syndrome-like symptoms before and after bariatric surgery and association with short-chain fermentable carbohydrates consumption: an observational prospective study

Background and aims

Irritable Bowel Syndrome (IBS)-like symptoms are frequent following bariatric surgery. This study aims to evaluate the frequency of IBS symptoms severity before and after bariatric surgery and their association with short-chain fermentable carbohydrates (FODMAPs) consumption.

Patients and methods

IBS symptoms severity in a cohort of obese patients was evaluated prospectively before, 6 and 12 months after bariatric surgery by validated questionnaires and tools (Irritable Bowel Syndrome Severity Scoring System (IBS SSS), Bristol Stool Scale (BSS), Quality of Life Short- Form-12 (SF-12), Hospital Anxiety and Depression scale (HAD)). FODMAPs consumption and its association with IBS symptom severity was evaluated by using a food frequency questionnaire focused on high-FODMAPs food consumption.

Results

Fifty-one patients were included (41 female; mean age 41 years (SD: 12)), 84% received a sleeve gastrectomy, and 16% a Roux-en-Y gastric bypass. Symptoms compatible with IBS were observed in 43% of patients before surgery, in 58% of patients at 6 months and 33% at 12 months (NS, p-value=0,197 and 0,414). In a multivariate model, a significant association was found between the IBS SSS score and lactose consumption at 6 months (β = + 58, 1; p = 0.03), and with polyols consumption at 12 months (β = + 112,6; p = 0.01).

Conclusions

Mild to moderate IBS symptoms are frequent in obese patients before bariatric surgery. A significant association between lactose and polyols consumption and IBS SSS score was observed after bariatric surgery, suggesting a potential link between the severity of IBS symptoms and some specific FODMAPs consumption.

A single, peri-operative antibiotic can persistently alter the post-operative gut microbiome after Roux-en-Y gastric bypass

INTRODUCTION

Roux-en-Y gastric bypass (RYGB) significantly alters the gut microbiome and may be a mechanism for post-operative cardiovascular disease improvement. We have previously found an association between the class of peri-operative, intravenous antibiotic administered at the time of RYGB and the resolution rate of hypertension suggesting the gut microbiome as a mechanism. In this study, we performed a prospective study of RYGB to determine if a single intravenous antibiotic could alter the gastrointestinal microbial composition.

METHODS

Patients undergoing RYGB were randomized to a single, peri-operative antibiotic of intravenous cefazolin (n = 8) or clindamycin (n = 8). Stool samples were collected from four-time points: 2 weeks pre-op (- 2w), 2 days pre-op (- 2d), 2 weeks post-op (+ 2w) and 3 months post-op (+ 3m). Stool samples were processed for genomic DNA followed by Illumina 16S rRNA gene sequencing and shotgun metagenomic sequencing (MGS).

RESULTS

A total of 60 stool samples (- 2w, n = 16; - 2d, n = 15; + 2w, n = 16; + 3m, n = 13) from 16 patients were analyzed. 87.5% of patients were female with an average age of 48.6 ± 12.2 years and pre-operative BMI of 50.9 ± 23.3 kg/m². RYGB induced statistically significant differences in alpha and beta diversity. There were statistically significant differences in alpha diversity at + 2w and beta diversity at + 3m due to antibiotic treatment. MGS revealed significantly distinct gut microbiota with 11 discriminatory metagenomic assembled genomes driven by antibiotic treatment at 3 months post-op, including increased Bifidobacterium spp. with clindamycin.

CONCLUSION

RYGB induces significant changes in the gut microbiome at 2 weeks that are maintained 3 months after surgery. However, the single peri-operative dose of antibiotic administered at the time of RYGB induces unique and persisting changes to the gut microbiome that are antibiotic-specific. Increased Bifidobacterium spp. with clindamycin administration may improve the metabolic efficacy of RYGB when considering gut-microbiome driven mechanisms for blood pressure resolution.

Gut microbiota modulation in patients with non-alcoholic fatty liver disease: Effects of current treatments and future strategies

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with metabolic disorders, being highly prevalent in obese and diabetic patients. Many concomitant factors that promote systemic and liver inflammation are involved in NAFLD pathogenesis, with a growing body of evidence highlighting the key role of the gut microbiota. Indeed, the gut-liver axis has a strong impact in the promotion of NAFLD and in the progression of the wide spectrum of its manifestations, claiming efforts to find effective strategies for gut microbiota modulation. Diet is among the most powerful tools; Western diet negatively affects intestinal permeability and the gut microbiota composition and function, selecting pathobionts, whereas Mediterranean diet fosters health-promoting bacteria, with a favorable impact on lipid and glucose metabolism and liver inflammation. Antibiotics and probiotics have been used to improve NAFLD features, with mixed results. More interestingly, medications used to treat NAFLD-associated comorbidities may also modulate the gut microbiota. Drugs for the treatment of type 2 diabetes mellitus (T2DM), such as metformin, glucagon-like peptide-1 (GLP-1) agonists, and sodium-glucose cotransporter (SGLT) inhibitors, are not only effective in the regulation of glucose homeostasis, but also in the reduction of liver fat content and inflammation, and they are associated with a shift in the gut microbiota composition towards a healthy phenotype. Even bariatric surgery significantly changes the gut microbiota, mostly due to the modification of the gastrointestinal anatomy, with a parallel improvement in histological features of NAFLD. Other options with promising effects in reprogramming the gut-liver axis, such as fecal microbial transplantation (FMT) and next-generation probiotics deserve further investigation for future inclusion in the therapeutic armamentarium of NAFLD.

Obesity and Its Multiple Clinical Implications between Inflammatory States and Gut Microbiotic Alterations

Obesity is a chronic multifactorial disease that has become a serious health problem and is currently widespread over the world. It is, in fact, strongly associated with many other conditions, including insulin resistance, type 2 diabetes, cardiovascular and neurodegenerative diseases, the onset of different types of malignant tumors and alterations in reproductive function. According to the literature, obesity is characterized by a state of low-grade chronic inflammation, with a substantial increase in immune cells, specifically macrophage infiltrates in the adipose tissue which, in turn, secrete a succession of pro-inflammatory mediators. Furthermore, recent studies on microbiota have postulated new possible mechanisms of interaction between obesity and unbalanced nutrition with inflammation. This intestinal "superorganism" complex seems to influence not only the metabolic balance of the host but also the immune response, favoring a state of systemic inflammation and insulin resistance. This review summarizes the major evidence on the interactions between the gut microbiota, energetic metabolism and host immune system, all leading to a convergence of the fields of immunology, nutrients physiology and microbiota in the context of obesity and its possible clinical complications. Finally, possible therapeutic approaches aiming to rebalance the intestinal microbial ecosystem are evaluated to improve the alteration of inflammatory and metabolic states in obesity and related diseases.

The role of bile acids and intestinal microbiota in metabolic transformations after gastric bypass surgery

Today, the positive impact of bariatric surgery on the course of type 2 diabetes mellitus has been studied in detail. At the same time, not only the effect of direct weight loss and the incretin theory, but also other mechanisms for normalizing glycemia are being actively discussed. Thus, special attention is paid to the metabolism of bile acids and their influence on various indicators of homeostasis, including carbohydrate metabolism. After bariatric interventions of the bypass type, the passage of bile through the gastrointestinal tract, as well as its interaction with food masses, changes significantly, which served as the basis for studying this phenomenon. The information accumulated to date indicates enormous changes occurring not only in the anatomy, but also in the biology of the gastrointestinal tract after bariatric bypass surgery. The composition of the intestinal microbiota and the composition of bile masses undergo significant changes. Most of the works available today suggest that these changes are the cause of a number of metabolic rearrangements, and directly affect carbohydrate metabolism. This issue is still under study and accumulation of the necessary information, but today it can be stated with confidence that the role of bile passage, bile acid circulation and restructuring of the intestinal microbiota in the regulation of carbohydrate metabolism and energy balance after bariatric bypass surgery is of extreme importance.

The changes in cognitive function following bariatric surgery considering the function of gut microbiome

Background

There is a correlation between gut microbiota and cognitive function. The mechanisms and pathways explain why the incidence of Alzheimer's disease in subjects undergoing bariatric surgery is lower than in other people with obesity.

Methods

In this review article, we aim to discuss the association of obesity, cognitive impairment, and physiological changes after bariatric surgery.

Results

Bariatric surgery has a series of physiological benefits which may lead to an improvement in cognitive functions in individuals who are prone to later developing Alzheimer's disease. Also, taxonomical change in the gut microbiome profile provides a healthy condition for living with better levels of cognition without neuropathological damages in older ages.

Conclusion

It can be concluded that there is a possible correlation between cognitive dysfunction and increased risk of cognitive dysfunction in people with a BMI higher than 40 kg/m2. Bariatric surgery may increase neurotransmitters and improve the gut bacteria, leading to a significant reduction in the risk of Alzheimer's disease.

Fecal Metabolome and Bacterial Composition in Severe Obesity: Impact of Diet and Bariatric Surgery

The aim of this study was to monitor the impact of a preoperative low-calorie diet and bariatric surgery on the bacterial gut microbiota composition and functionality in severe obesity and to compare sleeve gastrectomy (SG) versus Roux-en-Y gastric bypass (RYGB). The study also aimed to incorporate big data analysis for the omics results and machine learning by a Lasso-based analysis to detect the potential markers for excess weight loss. Forty patients who underwent bariatric surgery were recruited (14 underwent SG, and 26 underwent RYGB). Each participant contributed 4 fecal samples (baseline, post-diet, 1 month after surgery and 3 months after surgery). The bacterial composition was determined by 16S rDNA massive sequencing using MiSeq (Illumina). Metabolic signatures associated to fecal concentrations of short-chain fatty acids, amino acids, biogenic amines, gamma-aminobutyric acid and ammonium were determined by gas and liquid chromatography. Orange 3 software was employed to correlate the variables, and a Lasso analysis was employed to predict the weight loss at the baseline samples. A correlation between Bacillota (formerly Firmicutes) abundance and excess weight was observed only for the highest body mass indexes. The low-calorie diet had little impact on composition and targeted metabolic activity. RYGB had a deeper impact on bacterial composition and putrefactive metabolism than SG, although the excess weight loss was comparable in the two groups. Significantly higher ammonium concentrations were detected in the feces of the RYGB group. We detected individual signatures of composition and functionality, rather than a gut microbiota characteristic of severe obesity, with opposing tendencies for almost all measured variables in the two surgical approaches. The gut microbiota of the baseline samples was not useful for predicting excess weight loss after the bariatric process.

Extracellular vesicles and pasteurized cells derived from Akkermansia muciniphila protect against high-fat induced obesity in mice

Background

Several studies have shown that probiotics have beneficial effects on weight control and metabolic health. In addition to probiotics, recent studies have investigated the effects of paraprobiotics and postbiotics. Therefore, we evaluated the preventive effects of live and pasteurized Akkermansia muciniphila MucT (A. muciniphila) and its extracellular vesicles (EVs) on HFD-induced obesity.

Results

The results showed that body weight, metabolic tissues weight, food consumption, and plasma metabolic parameters were increased in the HFD group, whereas A. muciniphila preventive treatments inhibited these HFD. The effects of pasteurized A. muciniphila and its extracellular vesicles were more noticeable than its active form. The HFD led to an increase in the colonic, adipose tissue, and liver inflammations and increased the expression of genes involved in lipid metabolism and homeostasis. Nevertheless, these effects were inhibited in mice that were administered A. muciniphila and its EVs. The assessment of the gut microbiota revealed significant differences in the microbiota composition after feeding with HFD. However, all treatments restored the alterations in some bacterial genera and closely resemble the control group. Also, the correlation analysis indicated that some gut microbiota might be associated with obesity-related indices.

Conclusions

Pasteurized A. muciniphila and its EVs, as paraprobiotic and postbiotic agents, were found to play a key role in the regulation of metabolic functions to prevent obesity, probably by affecting the gut-adipose-liver axis.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01709-w.

Current Insights: The Impact of Gut Microbiota on Postoperative Complications in Visceral Surgery-A Narrative Review

Postoperative complications are a major problem occurring in up to 50% of patients undergoing major abdominal surgery. Occurrence of postoperative complications is associated with a significantly higher morbidity and mortality in affected patients. The most common postoperative complications are caused by an infectious genesis and include anastomotic leakage in case of gastrointestinal anastomosis and surgical site infections. Recent research highlighted the importance of gut microbiota in health and disease. It is plausible that the gut microbiota also plays a pivotal role in the development of postoperative complications. This narrative review critically summarizes results of recent research in this particular field. The review evaluates the role of gut microbiota alteration in postoperative complications, including postoperative ileus, anastomotic leakage, and surgical site infections in visceral surgery. We tried to put a special focus on a potential diagnostic value of pre- and post-operative gut microbiota sampling showing that recent data are inhomogeneous to identify a high-risk microbial profile for development of postoperative complications.

Changes in clinical depression following Sleeve Gastrectomy

INTRODUCTION

Bariatric surgery is safe and efficient surgical method for weight loss, but it is not free from complications. We aim to evaluate the prevalence of depression after Sleeve Gastrectomy (SG) in a narrow period of time on Iranian ethnicity.

METHODS

307 cases that underwent SG in Erfan Niayesh hospital were included. The questionnaire was based on International Classification of Diseases, Ninth Revision (ICD-9) codes to define diagnoses. Screening follow-up period was 20 to 24 months. The level of statistical significance was set at p < .05.

RESULTS

Of 307 subjects, preoperative depression was 30.2% and post-operative depression was 37.7% (p = .025). Besides, BMI, dyslipidaemia, good feelings about body size and weight loss were statistically significant at p < .05.There was an increased risk of depression following the procedure mainly in divorced cases.

CONCLUSION

The prevalence of clinical depression after sleeve gastrectomy was statistically significant and dependent on other variables. We provided guidance for people considering SG and their clinicians in terms of evaluating potential risks and benefits of surgery.

Evaluation of Helicobacter pylori Genotypes in Obese Patients with Gastric Ulcer, Duodenal Ulcer, and Gastric Cancer: An Observational Study

INTRODUCTION

Obesity is a well-known risk factor for a variety of gastrointestinal disorders (GID). Helicobacter pylori is associated with different GID, such as gastric cancer and chronic gastritis. In this study, we investigated the prevalence of dominant genotypes in H. pylori isolated from obese patients diagnosed with gastric ulcer, duodenal ulcer, and gastric cancer.

METHODS

A total of 222 H. pylori-positive samples were collected from patients with obesity. GID and gastric cancer were identified by endoscopy and histopathology, respectively. Three biopsy specimens from the gastric antrum were obtained from each patient for culture tests, histological examination, and identification of vacuolating cytotoxin A (vacA) (vacA s1, vacA s2, vacA m1, vacA m2, vacA s1m1 vacA s1m2, vacA s2m1, and vacA s2m2), cagA, cagE, iceA1, oipA, dupA, and babA2 using polymerase chain reaction.

RESULTS

vacA, cagE, cagA, iceA1, oipA, dupA, and babA2 genes were detected in 222 (100%), 171 (77%), 161 (72.5%), 77 (34.6%), 77 (34.6%), 137 (61%), and 69 (31%) patients with obesity, respectively. Our findings revealed that vacA, iceA1, oipA, and babA2 were significantly associated with a higher risk of GID, while cagE, cagA, and dupA indicated no correlation with the development of GID. Also, in the combination of s- and m-region genotypes, s1m2 (79%) was the most frequently identified genotype in patients with obesity. A significant association was also found between cagA and the presence of vacA genotypes (except for vacA m1 and babA2).

CONCLUSIONS

This study indicated the high prevalence of different virulence genes in H. pylori isolated from obese patients and supported the significant role of H. pylori in the development of GID.

Significance of intestinal microbiota in implementing metabolic effects of bariatric surgery

Bariatric surgery is among successful methods of obesity treatment, with effects going beyond weight reduction alone, but rather involving improved glucose tolerance, along with control or remission of the type 2 diabetes mellitus. The precise mechanisms causing metabolic effects of bariatric surgery are not fully elucidated, even though substantial evidence suggest that they include changes in the gut microbiota, bile acid homeostasis, and the close interactions of these factors. Intestinal microflora is directly involved in the energy metabolism of a host human. Obesity and type 2 diabetes mellitus are associated with certain changes in the species composition and diversity of intestinal microflora, which are considered important factors in the development and progression of these ailments. Bariatric surgery leads to significant and persistent changes in the composition of the intestinal microbiota, often bringing it closer to the characteristics of the microbiota of an average person with a normal weight. An important role in implementing the metabolic effects of bariatric surgery, primarily in the improvement of glucose metabolism, belongs to postoperative changes in homeostasis of bile acids. These changes imply close metabolism. Moreover, changes in the bile acid metabolism after bariatric surgery affect the microbiota of the host. Further study of these relationships would clarify the mechanisms underlying metabolic surgery, make it more predictable, targeted and controlled, as well as open new therapeutic targets in the treatment of obesity and associated conditions.

Modulation of the Gut Microbiota and Serum Biomarkers After Laparoscopic Sleeve Gastrectomy: a 1-Year Follow-Up Study

PURPOSE

Bariatric surgery is a treatment option for those affected by severe obesity. This study investigated changes in gut microbiota and serum biomarkers after laparoscopic sleeve gastrectomy (LSG).

MATERIALS AND METHODS

A total of 126 patients with morbid obesity who underwent LSG were enrolled in this study. Routine biochemical tests, hormonal (insulin and glucagon), and cytokine levels (IL-6, IL-1β, TNF-α, IL-10, and TGF-β 1) were measured, in addition, real-time PCR (quantitative PCR, qPCR) quantitated gut microbiota. All the parameters were measured pre-operatively, 3, and 12 months post-surgery (F0, F3, and F12, respectively).

RESULTS

At F3, the level of FBS, HbA1c, HOMA-IR, triglyceride, cholesterol, LDL, BUN, creatinine, urea, SGOT, SGPT, IL-1β, IL-6, IFNγ, insulin, glucagon, the abundance of Prevotella and Bacteroides fragilis group, as well as the concentration of Firmicutes spp. showed significant decrease (P < 0.01), and HDL level, Akkermansia muciniphila and Roseburia spp. abundance, and Bacteroidetes and Bifidobacterium spp. concentration showed significant increase (P < 0.0001). The observed pattern continued or remained stable at F12 for all of these variables. IL-10 and TGF-β1 remained unchanged until F3 and showed a significant drop at F12. At F3, Clostridium cluster IV increased significantly and remained at that level afterward. Moreover, concentration of Phylum Actinobacteria showed an initial drop at F3 and a later increase at F12 (P < 0.0001).

CONCLUSION

LSG is associated with a significant improvement in serum biomarkers, as well as significant changes in fecal microbiota. Future systems biology analyses would shed more light on the underlying interactions of these parameters, and could help in developing novel diagnostic and therapeutic strategies for obesity management.

Gut Microbiota and Serum Biomarker Analyses in Obese Patients Diagnosed with Diabetes and Hypothyroid Disorder

Background: Variations of serum biomarkers and bacterial diversity of the gastrointestinal tract in obese patients with diabetes or hypothyroid are poorly understood. The aim of this study was to provide recent findings in this regard. Methods: A total of 119 obese patients [17 with diabetes, 23 with hypothyroid, and 79 patients without either diabetes or hypothyroid (control)] were recruited in this study. Serum biomarkers such as biochemical, hormonal (insulin and glucagon), and cytokine levels [interleukin (IL)-6, IL-1β, tumor necrosis factor-alpha, IL-10, and transforming growth factor beta-1 (TGF-β1)] were measured under fasting conditions. Bacterial abundance of gut microbiota was also quantitated by real-time polymerase chain reaction using 16S rRNA gene-based specific primers. Results: Average value of blood sugar (P: 0.0184), hemoglobin A1c, insulin, homeostasis model assessment insulin resistance, TGF-β 1, IL-6, IL-1β, interferon gamma (P_{for each} < 0.001), and phylum Actinobacteria [odds ratio (OR): 1.5, P: 0.032] was significantly higher in diabetic versus control group. In contrast, the levels of IL-10 (P < 0.001), Firmicutes (OR: 0.6, P: 0.058), and Akkermansia muciniphila (OR: 0.4, P: 0.053) were significantly lower in diabetic versus control group. However, there was no statistically significant difference between the values in hypothyroid versus control group either in crude or adjusted models. Conclusion: While there are some relationships between serum biomarkers or bacterial abundance with diabetes prediction in obese patients, this prognostication is less likely in obese patients with hypothyroid. Further investigation is warranted in the application of identified preclinical biomarkers in the diagnosis of diabetes or hypothyroid in obese patients.

Comparison of methodological approaches to human gut microbiota changes in response to metabolic and bariatric surgery: A systematic review

Substantial differences in the response of gut microbial composition to metabolic and bariatric surgery have been reported. Therefore, the goal of the present review is to evaluate if methodological differences could be driving this lack of consistency. A search was conducted using PUBMED, Web of Science, Science Direct and COCHRANE using the following inclusion criteria: human studies written in English with a baseline sampling point, using gut microbiota as an outcome and either Roux-n-Y gastric bypass or sleeve gastrectomy. Sixteen articles were selected (total 221 participants). Roux-n-Y gastric bypass caused more alterations in gut microbial composition in comparison with sleeve gastrectomy. Substantial variability was found in study designs, data collection and analyses across studies. Increases in several families and genera from the phylum Proteobacteria and Bacteroidetes, the family Streptococcaceae, the species Akkermansia muciniphila and Streptococcus salivarius and a decrease in the phylum Firmicutes and the family Bifidobacteriaceae were reported. There is a need for standardization not only of microbial analysis but also of study designs when analysing the effect of bariatric surgery on the human gut microbiome. In addition, outcomes from different surgical procedures should not be combined as they produce distinctive effects on gut microbial composition.

The advantages and disadvantages of sleeve gastrectomy; clinical laboratory to bedside review

Sleeve gastrectomy is a surgical technique and a leading method in metabolic surgery. Sleeve gastrectomy gained ever-increasing popularity among laparoscopic surgeons involved in bariatric surgery and has proved to be a successful method in achieving considerable weight loss in a short time. There are some disparate effects that patients may experience after sleeve gastrectomy including a reduction in BMI, weight, blood pressure, stroke, and cancer and also a significant remission in obesity-related diseases including type 2 diabetes (T2D), Non-alcoholic fatty liver (NAFLD), cardiovascular disease, obstructive sleep apnea, and craniopharyngioma-related hypothalamic obesity as well as non-obesity-related diseases such as gout, musculoskeletal problems, ovarian disorders and urinary incontinence. The most common complications of sleeve gastrectomy are bleeding, nutrient deficiencies, and leakage. There are several studies on the impact of gender and ethnic disparities on post-operative complications. This study collects state of the art of reports on sleeve gastrectomy. The aim of this study was to analyze recent studies and review the advantages and disadvantages of sleeve gastrectomy.

Positional Vertigo and Unilateral Gradual Hearing Loss Following Sleeve Gastrectomy: A Case Report

Laparoscopic sleeve gastrectomy (LSG) is an effective treatment option in patients with morbid obesity, with rare long-term sideeffects. In this report, we present a 42-year-old woman who reported positional vertigo and unilateral gradual hearing loss plus continuous tinnitus after LSG. The patient had no signs or symptoms of mental health disorders and the results of the haematological and serum biochemical tests were normal. However, audiometric test revealed mild sensorineural hearing loss with magnitude in high-frequency tones. Also, acoustic reflex threshold showed neural pathway damage, particularly at high frequencies, with no reflex. Pure tone audiometry showed signs of nerve damage in the inner ear. One possible justification for these complications might be eustachian tube dysfunction due to muscle relaxation. Muscle relaxation itself may occur as a result of adipose tissue loss around the ear muscles. Further evidence, however, would be required to better determine whether these complications are attributable to LSG, and to illuminate exact underlying reasons for such complications.

Incidence and Determinants of Mental Health Service Use After Bariatric Surgery

Importance

Obesity is associated with an increased prevalence of psychiatric disorders. The association of bariatric surgery with mental health outcomes is poorly understood.

Objective

To investigate the association of bariatric surgery with the incidence of outpatient, emergency department (ED), and inpatient mental health service use.

Design, Setting, and Participants

This statewide, mirror-image, longitudinal cohort study used data from Western Australian Department of Health Data Linkage Branch records from all patients undergoing index (ie, first) bariatric surgery in Western Australia over a 10-year period (January 2007-December 2016), with mean (SD) follow-up periods of 10.2 (2.9) years before and 5.2 (2.9) years after index bariatric surgery. The data analysis was performed between November 2018 and March 2019.

Exposures

Index bariatric surgery.

Main Outcomes and Measures

The incidence and predictors for mental health presentations, deliberate self-harm, and suicide in association with the timing of bariatric surgery.

Results

A total of 24 766 patients underwent index bariatric surgery; of these, the mean (SD) age was 42.5 (11.7) years and 19 144 (77.3%) were women. Use of at least 1 mental health service occurred in 3976 patients (16.1%), with 1401 patients (35.2%) presenting only before surgery, 1025 (25.8%) presenting before and after surgery, and 1550 patients (39.0%) presenting only after surgery. There was an increase in psychiatric illness presentations after bariatric surgery (outpatient clinic attendance: incidence rate ratio [IRR], 2.3; 95% CI, 2.3-2.4; ED attendance: IRR, 3.0; 95% CI, 2.8-3.2; psychiatric hospitalization: IRR, 3.0; 95% CI, 2.8-3.1). There was also a 5-fold increase in deliberate self-harm presentations to an ED after surgery (IRR, 4.7; 95% CI, 3.8-5.7), with 25 of 261 postoperatives deaths (9.6%) due to suicide. Complications after bariatric surgery requiring further surgical intervention and a history of mental health service provision before surgery were the most important associations with subsequent mental health presentations after surgery. Deliberate self-harm and mental and behavioral disorders due to psychoactive substance use before bariatric surgery were the main associations with subsequent deliberate self-harm or suicide after surgery.

Conclusions and Relevance

We observed an increase in mental health service presentations after bariatric surgery, particularly among those who had prior psychiatric illnesses or developed surgical complications requiring further surgery. These findings caution the hypothesis that weight reduction by bariatric surgery will improve mental health in patients with obesity.

Akkermansia muciniphila-Derived Extracellular Vesicles as a Mucosal Delivery Vector for Amelioration of Obesity in Mice

Recent evidence suggests that probiotics can restore the mucosal barrier integrity, ameliorate inflammation, and promote homeostasis required for metabolism in obesity by affecting the gut microbiota composition. In this study, we investigated the effect of Akkermansia muciniphila and its extracellular vesicles (EVs) on obesity-related genes in microarray datasets and evaluated the cell line and C57BL/6 mice by conducting RT-PCR and ELISA assays. A. muciniphila-derived EVs caused a more significant loss in body and fat weight of high-fat diet (HFD)-fed mice, compared with the bacterium itself. Moreover, treatment with A. muciniphila and EVs had significant effects on lipid metabolism and expression of inflammatory markers in adipose tissues. Both treatments improved the intestinal barrier integrity, inflammation, energy balance, and blood parameters (i.e., lipid profile and glucose level). Our findings showed that A. muciniphila-derived EVs contain various biomolecules, which can have a positive impact on obesity by affecting the involved genes. Also, our results showed that A. muciniphila and its EVs had a significant relationship with intestinal homeostasis, which highlights their positive role in obesity treatment. In conclusion, A. muciniphila-derived EVs can be used as new therapeutic strategies to ameliorate HFD-induced obesity by affecting various mechanisms.

Metabolic and Endocrine Consequences of Bariatric Surgery

Obesity is one of the most serious worldwide epidemics of the twenty-first century according to the World Health Organization. Frequently associated with a number of comorbidities, obesity threatens and compromises individual health and quality of life. Bariatric surgery (BS) has been demonstrated to be an effective treatment to achieve not only sustained weight loss but also significant metabolic improvement that goes beyond mere weight loss. The beneficial effects of BS on metabolic traits are so widely recognized that some authors have proposed BS as metabolic surgery that could be prescribed even for moderate obesity. However, most of the BS procedures imply malabsorption and/or gastric acid reduction which lead to nutrient deficiency and, consequently, further complications could be developed in the long term. In fact, BS not only affects metabolic homeostasis but also has pronounced effects on endocrine systems other than those exclusively involved in metabolic function. The somatotropic, corticotropic, and gonadal axes as well as bone health have also been shown to be affected by the various BS procedures. Accordingly, further consequences and complications of BS in the long term in systems other than metabolic system need to be addressed in large cohorts, taking into account each bariatric procedure before making generalized recommendations for BS. In this review, current data regarding these issues are summarized, paying special attention to the somatotropic, corticotropic, gonadal axes, and bone post-operative health.