Changes in adipokine levels and metabolic profiles following bariatric surgery

Impact of surgical intervention on obstructive sleep apnea (OSA) and body-mass index: a scoping review

BACKGROUND

Upper airway surgery for obstructive sleep apnea (OSA) offers an alternative to CPAP, but its impact on weight changes is poorly studied.

PURPOSE

To systematically review published literature on the relationship between surgical intervention for OSA and changes in body mass index (BMI).

METHODS

A literature search was conducted from 2013-2024 in five databases. Full-text English articles which examined BMI changes in adults with OSA pre- and post-surgery were included. The quality of each study was assessed independently by two researchers using the Newcastle-Ottawa Scale. This study was reported according to the PRISMA-ScR.

RESULTS

Eleven studies, involving 406 patients from six countries were included. Most patients were males (88.4%) with a mean age of 40 years old. The pre-operative BMI were higher [27.8 kg/m2 (SD = 2.6)] compared to a BMI of 27.7 kg/m2 (SD = 1.3) at 21.0 months post-operation. The pre-operative Epworth Sleepiness Score was 13.28 (SD = 6.36), while the apnea-hypopnea index was 41.2 (SD = 16.88), indicating that most patients were diagnosed with severe OSA. The average oxygen desaturation index was 35.63 (SD = 11.17). The meta-analysis showed no significant BMI changes after surgery (mean difference:-0.29; 95% CI:-0.80 to 0.21; I2 = 30%). Findings were consistent with no publication bias found.

CONCLUSIONS

Upper airway surgery for OSA does not significantly affect BMI. The authors propose closer monitoring of weight changes following upper airway surgery, as weight fluctuations can impact the outcomes of surgery. Unchanged weight post-surgery may be attributed to suboptimal OSA treatment.

Sleeve Gastrectomy and Gastric Bypass Impact in Patient's Metabolic, Gut Microbiome, and Immuno-inflammatory Profiles-A Comparative Study

BACKGROUND

Bariatric surgery is the most long-term effective treatment option for severe obesity. The role of gut microbiome (GM) in either the development of obesity or in response to obesity management strategies has been a matter of debate. This study aims to compare the impact of two of the most popular procedures, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (GB), on metabolic syndrome parameters and gut bacterial microbiome and in systemic immuno-inflammatory response.

METHODS

A prospective observational study enrolled 24 patients with severe obesity, 14 underwent SG and 10 GB. Evaluations before (0 M) and 6 months (6 M) after surgical procedures included clinical and biochemical parameters, expression of 17 immuno-inflammatory genes in peripheral blood leukocytes, and assessment of gut microbiome profile using 16 s rRNA next-generation sequencing approach. Statistical significance was set to a p value < 0.05 with an FDR < 0.1.

RESULTS

A significant and similar decrease in weight-associated parameters and for most metabolic markers was achieved with both surgeries. Considering the gut microbiome in the whole study population, there was an increase in alpha diversity at family-level taxa. Beta diversity between SG and GB at 6 M showed near significant differences (p = 0.042) at genus levels. Analysis of the relative abundance of individual taxonomic groups highlighted differences between pre- and post-surgical treatment and between both approaches, namely, a higher representation of family Enterobacteriaceae and genera Veillonella and Enterobacteriaceae_unclassified after GB. Increased expression of immune-inflammatory genes was observed mainly for SG patients.

CONCLUSIONS

We conclude that SG and GB have similar clinical and metabolic outcomes but different impacts in the gut bacterial microbiome. Results also suggest reactivation of immune response after bariatric surgery.

Depression and obesity: Focus on factors and mechanistic links

Major depressive disorder (MDD) is defined as mood disorder causing a persistent loss of interest and despair for two weeks or greater, with related symptoms. Depression can interfere with daily life and can cause those affected to not work, study, eat, sleep, and enjoy previously enjoyed hobbies and life events as they did previously. If untreated, it can become a serious health condition. Depression is multifactorial with a variety of factors influencing the condition. These factors include: (1) poor diet and exercise, (2) socioeconomic status, (3) gender, (4) biological clocks, (5) genetics and epigenetics, and (6) personal stressors. Treatment of depressive disorders is thus also multifactorial and utilizes the following therapies: (1) diet and exercise, (2) bright light therapy, (3) cognitive behavioral therapy, and (4) pharmaceutical therapy. Obesity is defined as body mass index over 30 and above, is believed to be causally linked to MDD through both psychological and molecular means. Atypical depression, a common form of MDD, is most strongly correlated with a high proclivity for obesity. Obesity and depression have a bidirectional relationship, a patient experiencing either condition singularly is more likely to develop the other due to the neural links between the two, including emotional lability, physical health of the brain, hormones, cytokine secretion, appetite, diet and feeding habits, inflammatory state. In individuals consuming a high fat diet (HFD) commonly ingested by those with obesity, the gut-microbiome is altered leading to systemic inflammation and the dysregulation of mood and the HPA axis impacting their neural health. The purpose of this paper is to examine the interplay of potential molecular, psychological, societal, and environmental causal factors of depressive disorders and how obesity perpetuates depression. A secondary aim of this paper is to examine current interventions that may help improve those affected by both conditions.

The effect of ketogenic diet on adipokines levels: a systematic review and meta-analysis of randomized-controlled trials

BACKGROUND

Considering the impact of adipokines on metabolic syndrome-related disorders and even chronic illnesses, it would appear vital to look for efficient treatments for these variables. The goal of this study was to thoroughly examine how the ketogenic diet (KD) affects adipokines.

METHODS

Using standard keywords, the databases Scopus, PubMed/Medline, Web of Science, Cochrane, and Embase were searched to find all controlled trials looking into how KD affected adipokines (leptin, adiponectin, and ghrelin). By using a random-effects model analysis, pooled weighted mean difference and 95% confidence intervals were obtained.

RESULTS

This article featured twenty-two studies. The combined results demonstrated that, as compared to the control group, leptin levels in all populations are significantly lower when KD is adhered to (WMD: - 0.14 ng/ml, 95% CI: - 8.66, - 3.61, P < 0.001). On the other hand, no discernible impact of this diet on ghrelin and adiponectin concentrations was noted. The subgroup analysis results demonstrated that the drop in leptin levels was considerably higher in persons with BMI > 30 kg/m2 and in trials that followed the KD for ≤ 8 weeks than in the other groups.

CONCLUSIONS

Generally speaking, this diet can be utilized as a potentially helpful supplementary therapy to improve this adipokine, given the significance that leptin plays on numerous metabolic illnesses.

Changes in serum ghrelin and resistin levels after sleeve gastrectomy versus one anastomosis gastric bypass: prospective cohort study

INTRODUCTION

Humoral factors and neural mechanisms play a central role in the pathogenesis of obesity and in weight loss following bariatric surgery. Although various hormones and adipokines, including ghrelin and resistin, are linked to obesity, studies analyzing the changes in fasting ghrelin and resistin levels in patients following one anastomosis gastric bypass (OAGB) are lacking.

AIM

The authors aimed to investigate resistin and ghrelin levels before and after two commonly used bariatric procedures with different mechanisms of action: sleeve gastrectomy (SG) and OAGB.

PATIENTS AND METHODS

Fasting serum ghrelin and resistin levels were evaluated by using ELISA in a nonrandomized, prospective cohort study for the pattern of changes in the preoperative period and 1 week, 1 month, 3 months and, 12 months after surgery in age and sex-matched patients with BMI ≥40 kg/m 2 undergoing either SG ( n =40) or OAGB ( n =40). Their relationships with demographic parameters such as body weight, BMI, presence of T2DM, HbA 1 C, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index were also evaluated.

RESULTS

OAGB was superior in weight control compared to the SG group. There were significant differences in resistin and ghrelin levels between the OAGB and SG groups. Ghrelin decreased more in the SG group than the preoperative values. This change in ghrelin levels was more significant at 1 year after SG [preoperative mean (range) level of 334.2 (36.6-972.1) pg/ml decreased to 84 (9.1-227) pg/ml at 1 year] whereas in the OAGB group no significant change was observed [preoperative mean (range) level of 310 (146-548) pg/ml decreased to 264 (112-418) pg/ml at 1 year]. Resistin levels decreased in both groups, especially after 3 months and onward following both operations [the mean (range) resistin levels were 2.6 (0.87-5.4) ng/ml and decreased to 1.1 (0.5-2.4) ng/ml in the SG group vs 2.48 (0.89-6.43) ng/ml decreased to 0.72 (0.35-1.8) ng/ml in OAGB group at 1 year], which was in parallel with changes in HOMA-IR index, body weight, and BMI changes at 1st year. HOMA-IR index changes were similar, but more prominent after OAGB. OAGB was als3 three months and onward), and HOMA-IR changes.

CONCLUSION

This is the first study to compare fasting ghrelin and resistin levels after OAGB and SG. Although similar changes were observed, ghrelin changes were more prominent after SG, whereas resistin were observed after OAGB. OAGB was superior in T2DM control, which was in parallel with weight loss, fasting resistin levels, and HOMA-IR changes suggesting a possible effect of resistin after OAGB in glucose metabolism and insulin resistance.

Changes in Circulating Adipokine Levels in COVID-19 Patients

Objective: The COVID-19 pandemic has posed significant global health challenges. Despite extensive research efforts, the inflammatory response triggered by SARS-CoV-2 remains to be further explored and understood. Our study aims to examine the changes in serum concentrations of pro-inflammatory adipokines-visfatin and leptin-in COVID-19 patients in relation to a healthy control group. Patients/Materials/Subjects and Methods: The study consisted of forty COVID-19 patients and twenty-four healthy patients in the control group. Two serum samples were collected: upon admission and on the seventh day of hospitalization. Concentrations of visfatin and leptin in the serum, alongside routine biochemical parameters, were measured using enzyme immunoassay or enzyme-linked immunosorbent assay kits. The Shapiro-Wilk test was used to assess normality. Differences between independent groups were compared using the Mann-Whitney U test and Kruskal-Wallis ANOVA. Correlations were evaluated with Spearman's rank correlation coefficient. Results: Our findings revealed significantly lower visfatin levels in COVID-19 patients compared to the control group upon admission (4.29 ng/mL, (3.0-6.88 ng/mL) vs. 37.16 ng/mL (24.74-50.12 ng/mL), p < 0.001 for visfatin 1 and 52.05 ng/mL, (31.2-69.66 ng/mL) vs. 37.16 ng/mL (24.74-50.12 ng/mL), p = 0.048 for visfatin 2). The visfatin level of COVID-19 patients returned to the normal levels, established in the control group. However, there was no significant difference in leptin levels between the two groups (p = 0.270 for leptin 1 and p = 0.129 for leptin 2). There was a positive correlation between BMI and leptin concentration (r = 0.66 and p = 0.00). Moreover, it was discovered that COVID-19 independently reduces visfatin levels during the first day of illness. Conclusions: The results of our research suggest that the onset of COVID-19 infection is correlated to visfatin levels. Association with leptin levels remains inconclusive. Further research is imperative to elucidate the intricate role of visfatin and leptin in SARS-CoV-2 infection and their potential as biomarkers for COVID-19 severity and prognosis.

Physiological Archetypes of de novo Gastroesophageal Reflux Disease After Laparoscopic Sleeve Gastrectomy

Laparoscopic Sleeve Gastrectomy (LSG) is the most common bariatric surgery in the world. While clinically effective, recent studies have shown increasingly higher rates of gastroesophageal reflux disease (GERD) and esophageal motility disorders. We reviewed all the literature and unraveled the underlying mechanism of post-LSG GERD. Finally, we propose a new classification to help us understand the disease and guide work-up, treatment, and future refinements in the surgical technique.

Physiological Appetite Regulation and Bariatric Surgery

Obesity remains a common metabolic disorder and a threat to health as it is associated with numerous complications. Lifestyle modifications and caloric restriction can achieve limited weight loss. Bariatric surgery is an effective way of achieving substantial weight loss as well as glycemic control secondary to weight-related type 2 diabetes mellitus. It has been suggested that an anorexigenic gut hormone response following bariatric surgery contributes to weight loss. Understanding the changes in gut hormones and their contribution to weight loss physiology can lead to new therapeutic treatments for weight loss. Two distinct types of neurons in the arcuate hypothalamic nuclei control food intake: proopiomelanocortin neurons activated by the anorexigenic (satiety) hormones and neurons activated by the orexigenic peptides that release neuropeptide Y and agouti-related peptide (hunger centre). The arcuate nucleus of the hypothalamus integrates hormonal inputs from the gut and adipose tissue (the anorexigenic hormones cholecystokinin, polypeptide YY, glucagon-like peptide-1, oxyntomodulin, leptin, and others) and orexigeneic peptides (ghrelin). Replicating the endocrine response to bariatric surgery through pharmacological mimicry holds promise for medical treatment. Obesity has genetic and environmental factors. New advances in genetic testing have identified both monogenic and polygenic obesity-related genes. Understanding the function of genes contributing to obesity will increase insights into the biology of obesity. This review includes the physiology of appetite control, the influence of genetics on obesity, and the changes that occur following bariatric surgery. This has the potential to lead to the development of more subtle, individualised, treatments for obesity.

Reduced risk of de novo Barrett esophagus after bariatric surgery: a national database study

BACKGROUND

Bariatric surgery is an effective treatment for obesity and may decrease the morbidity and mortality of obesity-associated cancers.

OBJECTIVE

We investigated the risk of a new diagnosis of Barrett esophagus (BE) following bariatric surgery compared to screening colonoscopy controls.

SETTING

Large national database including patients who received care in inpatient, outpatient, and specialty care services.

METHODS

A national healthcare database (TriNetX, LLC) was used for this analysis. Cases included adults (aged ≥18 yr) who had undergone either sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB). Controls included adults undergoing screening colonoscopy and an esophagoduodenoscopy on the same day and had never undergone bariatric surgery. Cases and controls were propensity-matched for confounders. The risk of de novo diagnosis of BE at least 1 year after bariatric surgery was compared between cases and controls. Secondary analyses examined the effect of bariatric surgery on metabolic outcomes such as weight loss and body mass index (BMI). The risk of de novo diagnosis of BE in SG was compared with RYGB. Odds ratios (OR) and 95% CI were used to report on these associations.

RESULTS

In the propensity-matched analysis, patients who had undergone a bariatric surgical procedure showed a significantly reduced risk of de novo BE when compared with screening colonoscopy controls (.67 [.48, .94]). There was substantial reduction in weight and BMI in the bariatric surgery group when compared with baseline. There was no significant difference in de novo BE diagnosis between the propensity-matched SG and RYGB groups (.77 [.5, 1.2]).

CONCLUSION

Patients who underwent bariatric surgery (RYGB or SG) had a lower risk of being diagnosed with BE compared with screening colonoscopy controls who did not receive bariatric surgery. This effect appears to be largely mediated by reduction in weight and BMI.

Improved Insulin Secretion Response and Beta-cell Function Correlated with Increased Prolactin Levels After Laparoscopic Sleeve Gastrectomy in Morbidly Obese Patients with Acanthosis Nigricans

OBJECTIVE

To explore insulin secretion patterns, β-cell function, and serum prolactin (PRL) concentrations in Chinese morbidly obese patients with Acanthosis nigricans (AN) and their alterations after laparoscopic sleeve gastrectomy (LSG).

METHODS

A total of 138 morbidly obese subjects undergoing LSG were categorized as simple obesity without AN (OB group, n = 55) and obesity with AN (AN group, n = 83). Oral glucose tolerance test (OGTT), PRL, and related metabolic indices were performed pre- and 12 months post-LSG. Insulin secretion patterns were derived from insulin secretion peak time during OGTT: type I (peak at 30 or 60 min) and type II (peak at 120 or 180 min).

RESULTS

Preoperatively, AN group showed significantly higher proportions of type II insulin secretion pattern, fasting insulin (FINS), and homeostatic model assessment of insulin resistance (HOMA-IR) whereas lower oral glucose insulin sensitivity (OGIS), insulinogenic index (IGI), and disposition index (DI) than OB group, which were improved significantly at 12 months postoperatively in both groups, more pronounced in AN group. Intriguingly, serum PRL declined substantially in AN group than OB group at baseline whereas elevated only in the AN group post-LSG. After adjusting for confounding factors, elevated PRL correlated significantly with increased IGI and DI, and decreased HOMA-IR in both genders, as well as increased OGIS in females, which was detected only in the AN group CONCLUSION: Morbidly obese patients with AN presented delayed insulin secretion response, impaired insulin secretion, and β-cell dysfunction, which were significantly improved by LSG and might benefit from elevated PRL.

Effect of Laparoscopic Sleeve Gastrectomy on Serum Adipokine Levels

Bariatric procedures are considered to be the most effective treatment options for obesity. One of them is laparoscopic sleeve gastrectomy (LSG), which is nowadays very popular and widely used. LSG leads to weight loss and metabolic improvement and also changes adipokine levels, although it is just a restrictive operation. We describe changes in pro-inflammatory (leptin, resistin, visfatin and chemerin) and anti-inflammatory adipokines (adiponectin, omentin), with adiponectin and leptin being most studied. Their levels are markedly changed after LSG and this may partially explain the weight loss seen after LSG. Adipokines are closely connected to insulin resistance and chronic inflammation both being positively influenced after LSG. Leptin regulates amount of body fat, appetite, thermogenesis and metabolic rate and its levels are positively correlated with both weight and BMI changes after operation. Resistin influences insulin sensitivity, modulates body cholesterol trafficking and its changes after operation correlate with BMI, waist circumference, fat mass, LDL cholesterol and C-reactive protein. Chemerin, an important component of immune system, decreases after bariatric surgery and its levels correlate with BMI, triglyceride levels, and blood glucose. On the other hand, pro-inflammatory adipokine adiponectin, which influences fatty acid oxidation, browning of fat tissue and energy metabolism, is declining after LSG. This decline explains improvement of glucose status after bariatric surgery in patients with diabetes and is correlated with BMI loss, waist circumference and LDL cholesterol level. Effect of LSG goes beyond calory restriction and the changes of adipokines have a great impact on health status of the bariatric patients.

State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus

Obesity and type-2 diabetes mellitus (T2DM) are metabolic disorders. Obesity increases the risk of T2DM, and as obesity is becoming increasingly common, more individuals suffer from T2DM, which poses a considerable burden on health systems. Traditionally, pharmaceutical therapy together with lifestyle changes is used to treat obesity and T2DM to decrease the incidence of comorbidities and all-cause mortality and to increase life expectancy. Bariatric surgery is increasingly replacing other forms of treatment of morbid obesity, especially in patients with refractory obesity, owing to its many benefits including good long-term outcomes and almost no weight regain. The bariatric surgery options have markedly changed recently, and laparoscopic sleeve gastrectomy (LSG) is gradually gaining popularity. LSG has become an effective and safe treatment for type-2 diabetes and morbid obesity, with a high cost-benefit ratio. Here, we review the me-chanism associated with LSG treatment of T2DM, and we discuss clinical studies and animal experiments with regard to gastrointestinal hormones, gut microbiota, bile acids, and adipokines to clarify current treatment modalities for patients with obesity and T2DM.

Molecular Mechanisms of Western Diet-Induced Obesity and Obesity-Related Carcinogenesis-A Narrative Review

The present study aims to provide a narrative review of the molecular mechanisms of Western diet-induced obesity and obesity-related carcinogenesis. A literature search of the Cochrane Library, Embase and Pubmed databases, Google Scholar and the grey literature was conducted. Most of the molecular mechanisms that induce obesity are also involved in the twelve Hallmarks of Cancer, with the fundamental process being the consumption of a highly processed, energy-dense diet and the deposition of fat in white adipose tissue and the liver. The generation of crown-like structures, with macrophages surrounding senescent or necrotic adipocytes or hepatocytes, leads to a perpetual state of chronic inflammation, oxidative stress, hyperinsulinaemia, aromatase activity, activation of oncogenic pathways and loss of normal homeostasis. Metabolic reprogramming, epithelial mesenchymal transition, HIF-1α signalling, angiogenesis and loss of normal host immune-surveillance are particularly important. Obesity-associated carcinogenesis is closely related to metabolic syndrome, hypoxia, visceral adipose tissue dysfunction, oestrogen synthesis and detrimental cytokine, adipokine and exosomal miRNA release. This is particularly important in the pathogenesis of oestrogen-sensitive cancers, including breast, endometrial, ovarian and thyroid cancer, but also 'non-hormonal' obesity-associated cancers such as cardio-oesophageal, colorectal, renal, pancreatic, gallbladder and hepatocellular adenocarcinoma. Effective weight loss interventions may improve the future incidence of overall and obesity-associated cancer.

Systematic Review and Meta-Analysis of the Impact of Bariatric Surgery on Future Cancer Risk

The study aimed to perform a systematic review and meta-analysis of the evidence for the prevention of future cancers following bariatric surgery. A systematic literature search of the Cochrane Library, Embase, Scopus, Web of Science and PubMed databases (2007–2023), Google Scholar and grey literature was conducted. A meta-analysis was performed using the inverse variance method and random effects model. Thirty-two studies involving patients with obesity who received bariatric surgery and control patients who were managed with conventional treatment were included. The meta-analysis suggested bariatric surgery was associated with a reduced overall incidence of cancer (RR 0.62, 95% CI 0.46–0.84, p < 0.002), obesity-related cancer (RR 0.59, 95% CI 0.39–0.90, p = 0.01) and cancer-associated mortality (RR 0.51, 95% CI 0.42–0.62, p < 0.00001). In specific cancers, bariatric surgery was associated with reduction in the future incidence of hepatocellular carcinoma (RR 0.35, 95% CI 0.22–0.55, p < 0.00001), colorectal cancer (RR 0.63, CI 0.50–0.81, p = 0.0002), pancreatic cancer (RR 0.52, 95% CI 0.29–0.93, p = 0.03) and gallbladder cancer (RR 0.41, 95% CI 0.18–0.96, p = 0.04), as well as female specific cancers, including breast cancer (RR 0.56, 95% CI 0.44–0.71, p < 0.00001), endometrial cancer (RR 0.38, 95% CI 0.26–0.55, p < 0.00001) and ovarian cancer (RR 0.45, 95% CI 0.31–0.64, p < 0.0001). There was no significant reduction in the incidence of oesophageal, gastric, thyroid, kidney, prostate cancer or multiple myeloma after bariatric surgery as compared to patients with morbid obesity who did not have bariatric surgery. Obesity-associated carcinogenesis is closely related to metabolic syndrome; visceral adipose dysfunction; aromatase activity and detrimental cytokine, adipokine and exosomal miRNA release. Bariatric surgery results in long-term weight loss in morbidly obese patients and improves metabolic syndrome. Bariatric surgery may decrease future overall cancer incidence and mortality, including the incidence of seven obesity-related cancers.

Pre-Operative Assessment of Micronutrients, Amino Acids, Phospholipids and Oxidative Stress in Bariatric Surgery Candidates

Obesity has been linked to lower concentrations of fat-soluble micronutrients and higher concentrations of oxidative stress markers as well as an altered metabolism of branched chain amino acids and phospholipids. In the context of morbid obesity, the aim of this study was to investigate whether and to which extent plasma status of micronutrients, amino acids, phospholipids and oxidative stress differs between morbidly obese (n = 23) and non-obese patients (n = 13). In addition to plasma, malondialdehyde, retinol, cholesterol and triglycerides were assessed in visceral and subcutaneous adipose tissue in both groups. Plasma γ-tocopherol was significantly lower (p < 0.011) in the obese group while other fat-soluble micronutrients showed no statistically significant differences between both groups. Branched-chain amino acids (all p < 0.008) and lysine (p < 0.006) were significantly higher in morbidly obese patients compared to the control group. Malondialdehyde concentrations in both visceral (p < 0.016) and subcutaneous (p < 0.002) adipose tissue were significantly higher in the morbidly obese group while plasma markers of oxidative stress showed no significant differences between both groups. Significantly lower plasma concentrations of phosphatidylcholine, phosphatidylethanolamine, lyso-phosphatidylethanolamine (all p < 0.05) and their corresponding ether-linked analogs were observed, which were all reduced in obese participants compared to the control group. Pre-operative assessment of micronutrients in patients undergoing bariatric surgery is recommended for early identification of patients who might be at higher risk to develop a severe micronutrient deficiency post-surgery. Assessment of plasma BCAAs and phospholipids in obese patients might help to differentiate between metabolic healthy patients and those with metabolic disorders.

Neurohormonal Changes in the Gut-Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut-brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut-brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.