Alterations of Gut Microbiota After Biliopancreatic Diversion with Duodenal Switch in Wistar Rats

Effects of Lacticaseibacillus rhamnosus HA-114 probiotic supplementation on circulating IGFBP-2 levels during a calorie-restricted diet in overweight humans

Background and aim

Gut microbiota influences energy homeostasis in part through circulating hormones. Insulin-like growth factor-binding protein (IGFBP)-2 is a biomarker whose increase in systemic circulation is associated with positive effects on body weight and metabolism. In a recent clinical trial, probiotic Lacticaseibacillus rhamnosus HA-114 supplementation showed positive effects on eating behaviors and insulin resistance in overweight participants undergoing a weight-loss intervention. In this context, this ancillary study aimed at assessing the impact of L. rhamnosus HA-114 supplementation on plasma IGFBP-2 levels in these individuals, and whether this modulation correlated with changes in fat mass, energy metabolism, and eating behaviors.

Methods

Fasting plasma IGFBP-2 concentrations were quantified in 100 overweight or obese men and women enrolled in a 12-week diet-based weight reduction program (-500 kcal/day), in combination with probiotic L. rhamnosus HA-114 or placebo supplementation. Baseline and changes in circulating IGFBP-2 concentrations were correlated with anthropometric parameter, glucose and lipid metabolism, cardiorespiratory function and eating behaviors.

Results

On average, the intervention reduced BMI by 4.6 % and increased IGFBP-2 by 13 %, regardless of supplementation group. Individuals who presented an increase in IGFBP-2 levels had significantly greater reductions in BMI. Changes in IGFBP-2 levels were correlated with loss in fat mass (r = 0.2, p < 0.001) in the probiotic-supplemented group, but not with other metabolic parameters or eating behaviors. Baseline IGFBP-2 levels were not associated with weight loss or improvements in cardiometabolic parameters.

Conclusion

Probiotic supplementation with L. rhamnosus HA-114 did not modulate plasma IGFBP-2 levels. Changes in IGFBP-2 levels were correlated with greater reductions in BMI, but not with other metabolic parameters or eating behaviors, indicating that the benefits of HA-114 on eating behaviors are likely independent of IGFBP-2. Additional changes in microbiota might be required to modulate IGFBP-2 and observe its associations with eating behaviors and cardiometabolic improvements.

Preoperative predictors of type 2 diabetes remission after bilio-pancreatic diversion with duodenal switch

BACKGROUND

Many patients achieve short-term type 2 diabetes (T2D) remission after bariatric surgery, but relapses are common. Diabetes outcomes after bariatric surgery vary across procedures and populations. T2D remission scores are simple clinical tools developed to predict remission after bariatric surgery. However, they have never been tested after Biliopancreatic diversion with duodenal switch (BPD-DS).

OBJECTIVES

The aim of this study was to compare the predictive value of T2D remission scores and preoperative diabetes characteristics in predicting T2D remission after BPD-DS.

SETTING

Quebec Heart and Lung Institute - Laval University.

METHODS

We retrospectively identified 918 patients with preoperative T2D who had undergone BPD-DS. Retrospective chart review was performed and variables used to calculate predictive scores were captured. T2D status was assessed annually for up to 10 years postop. Predictive values for each score (DiarRem, Ad Diarem, and Diabetter) and single preoperative diabetes characteristics used to construct these algorithms were evaluated by area under receiver operating characteristic curves (AUC).

RESULTS

Diabetter showed greater performance for prediction of durable diabetes remission than other algorithms with acceptable discriminative ability (AUC between .69 and .79), but was not superior to T2D duration as a single predictor (P = .24 and P = .18). At 10 years, T2D duration had a better discriminative ability for the prediction of T2D remission than all 3 predictive models (AUC = .85, P < .05).

CONCLUSIONS

Better chances for T2D remission following BPD-DS are associated with a shorter duration or T2D before surgery. Duration of T2D alone offers an excellent predictive ability and is a convenient alternative to diabetes remission scores to estimate chances of long-term diabetes remission after BPD-DS.

Effects of single-anastomosis duodenal-ileal bypass with sleeve gastrectomy on gut microbiota and glucose metabolism in rats with type 2 diabetes

Background

Bariatric and metabolic surgery often leads to significant changes in gut microbiota composition, indicating that changes in gut microbiota after bariatric and metabolic surgery might play a role in ameliorating type 2 diabetes (T2D). However, the effects of single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) on gut microbiota in T2D remain unclear.

Objectives

To investigate the effects of SADI-S on gut microbiota and glucose metabolism in T2D rats.

Methods

Nineteen T2D rats were randomly divided into the SADI-S group (n = 10) and the sham operation with pair-feeding group (sham-PF, n = 9). Fecal samples were collected to analyze the gut microbiota composition with 16S ribosomal DNA gene sequencing. The fasting blood glucose and glycated hemoglobin were measured to evaluate the effects of SADI-S on glucose metabolism.

Results

The Chao and ACE index results indicated the richness of the gut microbial community. The ACE and Chao index values were significantly lower in the SADI-S group than in the sham-PF group, indicating that indicating that species richness was significantly lower in the SADI-S group than in the sham-PF group (p < 0.05). Shannon and Simpson indices were used to estimate the species diversity of the gut microbiota. Compared with the sham-PF group, the SADI-S group showed significantly lower Shannon index and higher Simpson index values, indicating that the species diversity was significantly lower in the SADI-S group than in the sham-PF group (p < 0.05). At the genus level, SADI-S significantly changed the abundances of 33 bacteria, including the increased anti-inflammatory bacteria (Akkermansia and Bifidobacterium) and decreased pro-inflammatory bacteria (Bacteroides). SADI-S significantly decreased the fasting blood glucose and glycated hemoglobin levels. The blood glucose level of rats was positively correlated with the relative abundances of 12 bacteria, including Bacteroides, and negatively correlated with the relative abundances of seven bacteria, including Bifidobacterium.

Conclusion

SADI-S significantly altered the gut microbiota composition of T2D rats, including the increased anti-inflammatory bacteria (Akkermansia and Bifidobacterium) and decreased pro-inflammatory bacteria (Bacteroides). The blood glucose level of rats was positively correlated with the abundances of 12 bacteria, including Bacteroides, but negatively correlated with the relative abundance of 7 bacteria, including Bifidobacterium. These alternations in gut microbiota may be the mechanism through which SADI-S improved T2D. More studies should be performed in the future to validate these effects.

Gut microbiota and therapy for obesity and type 2 diabetes

There has been a major increase in Type 2 diabetes and obesity in many countries, and this will lead to a global public health crisis, which not only impacts on the quality of life of individuals well but also places a substantial burden on healthcare systems and economies. Obesity is linked to not only to type 2 diabetes but also cardiovascular diseases, musculoskeletal disorders, and certain cancers, also resulting in increased medical costs and diminished quality of life. A number of studies have linked changes in gut in obesity development. Dysbiosis, a deleterious change in gut microbiota composition, leads to altered intestinal permeability, associated with obesity and Type 2 diabetes. Many factors affect the homeostasis of gut microbiota, including diet, genetics, circadian rhythms, medication, probiotics, and antibiotics. In addition, bariatric surgery induces changes in gut microbiota that contributes to the metabolic benefits observed post-surgery. Current obesity management strategies encompass dietary interventions, exercise, pharmacotherapy, and bariatric surgery, with emerging treatments including microbiota-altering approaches showing promising efficacy. While pharmacotherapy has demonstrated significant advancements in recent years, bariatric surgery remains one of the most effective treatments for sustainable weight loss. However, access to this is generally limited to those living with severe obesity. This underscores the need for non-surgical interventions, particularly for adolescents and mildly obese patients. In this comprehensive review, we assess longitudinal alterations in gut microbiota composition and functionality resulting from the two currently most effective anti-obesity treatments: pharmacotherapy and bariatric surgery. Additionally, we highlight the functions of gut microbiota, focusing on specific bacteria, their metabolites, and strategies for modulating gut microbiota to prevent and treat obesity. This review aims to provide insights into the evolving landscape of obesity management and the potential of microbiota-based approaches in addressing this pressing global health challenge.

Hypoabsorptive surgeries cause limb-dependent changes in the gut endocannabinoidome and microbiome in association with beneficial metabolic effects

OBJECTIVE

To determine whether the metabolic benefits of hypoabsorptive surgeries are associated with changes in the gut endocannabinoidome (eCBome) and microbiome.

METHODS

Biliopancreatic diversion with duodenal switch (BPD-DS) and single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) were performed in diet-induced obese (DIO) male Wistar rats. Control groups fed a high-fat diet (HF) included sham-operated (SHAM HF) and SHAM HF-pair-weighed to BPD-DS (SHAM HF-PW). Body weight, fat mass gain, fecal energy loss, HOMA-IR, and gut-secreted hormone levels were measured. The levels of eCBome lipid mediators and prostaglandins were quantified in different intestinal segments by LC-MS/MS, while expression levels of genes encoding eCBome metabolic enzymes and receptors were determined by RT-qPCR. Metataxonomic (16S rRNA) analysis was performed on residual distal jejunum, proximal jejunum, and ileum contents.

RESULTS

BPD-DS and SADI-S reduced fat gain and HOMA-IR, while increasing glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) levels in HF-fed rats. Both surgeries induced potent limb-dependent alterations in eCBome mediators and in gut microbial ecology. In response to BPD-DS and SADI-S, changes in gut microbiota were significantly correlated with those of eCBome mediators. Principal component analyses revealed connections between PYY, N-oleoylethanolamine (OEA), N-linoleoylethanolamine (LEA), Clostridium, and Enterobacteriaceae_g_2 in the proximal and distal jejunum and in the ileum.

CONCLUSIONS

BPD-DS and SADI-S caused limb-dependent changes in the gut eCBome and microbiome. The present results indicate that these variables could significantly influence the beneficial metabolic outcome of hypoabsorptive bariatric surgeries.

Human gut microbiota after bariatric surgery alters intestinal morphology and glucose absorption in mice independently of obesity

OBJECTIVE

Bariatric surgery is an effective treatment for type 2 diabetes (T2D) that changes gut microbial composition. We determined whether the gut microbiota in humans after restrictive or malabsorptive bariatric surgery was sufficient to lower blood glucose.

DESIGN

Women with obesity and T2D had biliopancreatic diversion with duodenal switch (BPD-DS) or laparoscopic sleeve gastrectomy (LSG). Faecal samples from the same patient before and after each surgery were used to colonise rodents, and determinants of blood glucose control were assessed.

RESULTS

Glucose tolerance was improved in germ-free mice orally colonised for 7 weeks with human microbiota after either BPD-DS or LSG, whereas food intake, fat mass, insulin resistance, secretion and clearance were unchanged. Mice colonised with microbiota post-BPD-DS had lower villus height/width and crypt depth in the distal jejunum and lower intestinal glucose absorption. Inhibition of sodium-glucose cotransporter (Sglt)1 abrogated microbiota-transmissible improvements in blood glucose control in mice. In specific pathogen-free (SPF) rats, intrajejunal colonisation for 4 weeks with microbiota post-BPD-DS was sufficient to improve blood glucose control, which was negated after intrajejunal Sglt-1 inhibition. Higher Parabacteroides and lower Blautia coincided with improvements in blood glucose control after colonisation with human bacteria post-BPD-DS and LSG.

CONCLUSION

Exposure of rodents to human gut microbiota after restrictive or malabsorptive bariatric surgery improves glycaemic control. The gut microbiota after bariatric surgery is a standalone factor that alters upper gut intestinal morphology and lowers Sglt1-mediated intestinal glucose absorption, which improves blood glucose control independently from changes in obesity, insulin or insulin resistance.

Impact of biliopancreatic diversion with duodenal switch on glucose homeostasis and gut hormones and their correlations with appetite

BACKGROUND

Biliopancreatic diversion with duodenal switch (BPD/DS) results in lifelong changes in gastrointestinal physiology with unclear associations with appetite perception.

OBJECTIVE

To explore mixed meal-induced changes in glucose homeostasis and gut hormones and their correlations with appetite perception.

SETTING

University hospital.

METHODS

Of 28 patients studied preoperatively (age: 38.4 ± 11.3 years; body mass index [BMI]: 56.5 ± 5.1 kg/m²; 14 women), 19 (68%) returned for postoperative follow-up. Plasma was sampled for 180 minutes during a 260-kcal standardized mixed meal. Concentrations of leptin, glucose, insulin, triglycerides, active acyl-ghrelin, motilin, total glucose-dependent insulinotropic polypeptide (GIP), active glucagon-like peptide 1 (GLP-1), and total peptide YY (PYY) were measured. Subjective appetite sensations were scored.

RESULTS

BPD/DS resulted in 66.1% ± 23.3% excess BMI loss. Leptin was halved. Glucose and insulin levels were reduced, blunting a preoperative peak at 30 minutes, giving a lower homeostasis model assessment for insulin resistance (HOMA-IR; 13.9 versus 4.8). In contrast, reduced ghrelin and motilin concentrations were accompanied by pronounced peaks 20-30 minutes prior to meal responses. GIP was reduced, whereas GLP-1 and PYY responses were markedly increased, with an early postprandial peak (P < .05, for all). HOMA-IR correlated with insulin (r = .72) and GIP (r = .57). Postoperatively, satiety correlated with GLP-1 (r = .56), whereas the gastric motility index correlated with the desire to eat (r = .60), percentage excess BMI loss (r = -.55), and percentage total weight loss (r = -.49). Delta insulin, GLP-1, and leptin correlated positively with percentage total weight loss (r = .51, r = .48, and r = .58, respectively).

CONCLUSIONS

BPD/DS reduces leptin, HOMA-IR, and GIP while markedly increasing GLP-1 and PYY. This study marks the magnitude change in GLP-1 with additional effects of PYY as important factors for weight loss.

Renal Function Following Bariatric Surgery: a Literature Review of Potential Mechanisms

Obesity is a major and independent risk factor for onset and progression of many renal diseases. Bariatric surgery (BS) improves renal function by improving obesity-related metabolic disorders. However, the procedure is also accompanied by renal risks, including acute kidney injury (AKI) and oxalate nephropathy. Here, we briefly review the history and principle of frequently applied technique for BS and summarize the comprehensive BS effect on kidney function. Importantly, we highlight the possible molecular mechanisms associated with the recovery of renal function to provide novel ideas for future studies and clinical applications.

Consistent gut bacterial and short-chain fatty acid signatures in hypoabsorptive bariatric surgeries correlate with metabolic benefits in rats

OBJECTIVE

The study aimed at comparing how changes in the gut microbiota are associated to the beneficial effects of the most clinically efficient hypoabsorptive bariatric procedures, namely Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion with duodenal switch (BPD-DS) and single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S).

METHODS

Diet-induced obese (DIO) male Wistar rats were divided into seven groups. In addition to the groups subjected to RYGB, BPD-DS and SADI-S, the following four control groups were included: SHAM-operated rats fed a high-fat diet (SHAM HF), SHAM fed a low-fat diet (SHAM LF), SHAM HF-pair-weighed to BPD-DS (SHAM HF-PW) and sleeve-gastrectomy (SG) rats. Body weight, food intake, glucose tolerance, insulin sensitivity/resistance, and L-cell secretion were assessed. The gut microbiota (16 S ribosomal RNA gene sequencing) as well as the fecal and cæcal contents of short-chain fatty acids (SCFAs) were also analyzed prior to, and after the surgeries.

RESULTS

The present study demonstrates the beneficial effect of RYGB, BPD-DS and SADI-S on fat mass gain and glucose metabolism in DIO rats. These benefits were proportional to the effect of the surgeries on food digestibility (BPD-DS > SADI-S > RYGB). Notably, hypoabsorptive surgeries led to consonant microbial signatures characterized by decreased abundance of the Ruminococcaceae (Oscillospira and Ruminococcus), Oscillospiraceae (Oscillibacter) and Christensenellaceae, and increased abundance of the Clostridiaceae (Clostridium), Sutterellaceae (Sutterella) and Enterobacteriaceae. The gut bacteria following hypoabsorptive surgeries were associated with higher fecal levels of propionate, butyrate, isobutyrate and isovalerate. Increases in the fecal SCFAs were in turn positively and strongly correlated with the levels of peptide tyrosine-tyrosine (PYY) and with the beneficial effects of the surgery.

CONCLUSION

The present study emphasizes the consistency with which the three major hypoabsorptive bariatric procedures RYGB, BPD-DS and SADI-S create a gut microbial environment capable of producing a SCFA profile favorable to the secretion of PYY and to beneficial metabolic effects.

Evaluation of Lipoprotein Profile and Residual Risk Three Years After Bariatric Surgery

INTRODUCTION

Obesity is a chronic disease associated with other comorbidities, including atherogenic dyslipidemia (AD). Bariatric surgery (BS) has shown to reduce cardiovascular risk (CVR) by achieving a significant weight reduction and improving the lipid profile. Different surgical techniques may have a different effect on the lipoprotein profile.

PURPOSE

To evaluate the lipid profile at 3 years after BS according to the surgical technique used and to determine which variables predict variation in the lipid profile at 3 years after BS.

METHODS

Retrospective observational study of 206 patients who underwent BS between 2010 and 2019. We analyzed the variation of lipid parameters in the 3 years of follow-up according to the surgical technique, including a group analysis of patients according to whether they had dyslipidemia and whether they were treated or untreated and determined which variables predict variation in the lipid profile at 3 years after BS.

RESULTS

There was a significant increase in high-density lipoprotein cholesterol (HDL-c) with sleeve gastrectomy (SG) and a significant decrease in total cholesterol (TC), LDL-cholesterol (LDL-c), non-HDL, and LDL/non-HDL with biliopancreatic diversion (BPD). Variables predicting lipid profile variation were surgical technique and pre-surgery lipoprotein level.

CONCLUSIONS

Malabsorptive techniques achieve a greater decrease in TC and LDL-c throughout follow-up and could also improve residual cardiovascular risk (non-HDL and LDL/non-HDL). The type of surgical technique and the presurgery lipid profile predict variation after 3 years of BS.

Gut Microbiota, Probiotics and Psychological States and Behaviors after Bariatric Surgery-A Systematic Review of Their Interrelation

The gastrointestinal (GI) microbiota plays an important role in health and disease, including brain function and behavior. Bariatric surgery (BS) has been reported to result in various changes in the GI microbiota, therefore demanding the investigation of the impact of GI microbiota on treatment success. The goal of this systematic review was to assess the effects of BS on the microbiota composition in humans and other vertebrates, whether probiotics influence postoperative health, and whether microbiota and psychological and behavioral factors interact. A search was conducted using PubMed and Web of Science to find relevant studies with respect to the GI microbiota and probiotics after BS, and later screened for psychological and behavioral parameters. Studies were classified into groups and subgroups to provide a clear overview of the outcomes. Microbiota changes were further assessed for whether they were specific to BS in humans through the comparison to sham operated controls in other vertebrate studies. Changes in alpha diversity appear not to be specific, whereas dissimilarity in overall microbial community structure, and increases in the abundance of the phylum Proteobacteria and Akkermansia spp. within the phylum Verrucomicrobia after surgery were observed in both human and other vertebrates studies and may be specific to BS in humans. Human probiotic studies differed regarding probiotic strains and dosages, however it appeared that probiotic interventions were not superior to a placebo for quality of life scores or weight loss after BS. The relationship between GI microbiota and psychological diseases in this context is unclear due to insufficient available data.