Roux-en-Y gastric bypass affects the expression of genes related to the intestinal folate metabolism pathway in obese women.

OBJECTIVES: Roux-en-Y gastric bypass (RYGB) promotes sustained weight loss, and the resulting new gastrointestinal anatomy can contribute to nutritional depletions. Folate deficiency is one of the most frequently observed nutritional deficiencies after RYGB. The aim of this study was to assess whether RYGB affects the expression of genes related to the intestinal folate metabolism pathway as an additional molecular mechanism contributing to its postoperative deficiency. METHODS: Biopsies from the duodenum, jejunum, and ileum of 20 obese women were collected before and 3 mo after RYGB. The expression of genes involved in intestinal folate metabolism was assessed by microarray and reverse transcriptase polymerase chain reaction (RT-qPCR). Folate intake (7-d food record) and plasma levels (electrochemiluminescence) also were measured. RESULTS: Compared with the preoperative phase, transcriptomic alterations were observed in all intestinal segments studied after RYBG, mainly marked by decreased expression of genes encoding folate transporters/receptors and increased expression of genes involved in folate biosynthesis (P < 0.05). Reduced folate intake and plasma folate levels were also observed simultaneously (P < 0.05). Plasma folate concentrations correlated inversely with intestinal FOLR2 and SHMT2 genes (P < 0.001). CONCLUSION: The present findings suggested that impaired expression of genes related to intestinal folate metabolism may contribute to the early systemic deficiency after RYGB and highlight a potential transcriptomic reprogramming of the intestine in response to RYGB to compensate for folate depletion induced by this surgical technique.

Red Meat Intake, Indole-3-Acetate, and Dorea longicatena Together Affect Insulin Resistance after Gastric Bypass.

Roux-en-Y Gastric bypass (RYGB) promotes improvement in type 2 diabetes (T2D) shortly after surgery, with metabolic mechanisms yet to be elucidated. This study aimed to investigate the relationship between food intake, tryptophan metabolism, and gut microbiota on the glycemic control of obese T2D women after RYGB surgery. Twenty T2D women who underwent RYGB were evaluated before and three months after surgery. Food intake data were obtained by a seven-day food record and a food frequency questionnaire. Tryptophan metabolites were determined by untargeted metabolomic analysis, and the gut microbiota was determined by 16S rRNA sequencing. The glycemic outcomes were fasting blood glucose, HbA1C, HOMA-IR, and HOMA-beta. Linear regression models were applied to assess the associations between the changes in food intake, tryptophan metabolism, and gut microbiota on glycemic control after RYGB. All variables changed after RYGB (p < 0.05), except for tryptophan intake. Jointly, the variation in red meat intake, plasma indole-3-acetate, and Dorea longicatena was associated with postoperative HOMA-IR {R2 0.80, R2 adj 0.74; p < 0.01}. Red meat intake decreased three months after bariatric surgery while indole-3-acetate and Dorea longicatena increased in the same period. These combined variables were associated with better insulin resistance in T2D women after RYGB.

Gastrointestinal genetic reprogramming of vitamin A metabolic pathways in response of Roux-en-Y gastric bypass.

Roux-en-Y gastric bypass (RYGB) is one of the most performed bariatric surgical techniques. However, RYGB commonly results, as side effects, in nutritional deficiencies. This study aimed to examine changes in the expression of vitamin A pathway encoding genes in the gastrointestinal tract (GI) and to evaluate the potential mechanisms associated with hypovitaminosis A after RYGB. Intestinal biopsies were obtained through double-balloon endoscopy in 20 women with obesity (age 46.9±6.2 years; body mass index [BMI] 46.5±5.3 kg/m2 [mean±SD]) before and three months after RYGB (BMI, 38.2±4.2 kg/m2). Intestinal mucosal gene microarray analyses were performed in samples using a Human GeneChip 1.0 ST array (Affymetrix). Vitamin A intake was assessed from 7-day food records and serum retinol levels were evaluated by electrochemiluminescence immunoassay. Our results showed the following genes with significant downregulation (p≤0.05): LIPF (-0.60), NPC1L1 (-0.71), BCO1 (-0.45), and RBP4 (-0.13) in duodenum; CD36 (-0.33), and ISX (-0.43) in jejunum and BCO1 (-0.29) in ileum. No significant changes in vitamin A intake were found (784±694 retinol equivalents [RE] pre-operative vs. 809±753 RE post-operative [mean±SD]). Although patients were routinely supplemented with 3500 international units IU/day (equivalent to 1050 µg RE/day) of oral retinol palmitate, serum concentrations were lower in the post-operative when compared to pre-operative period (0.35±0.14 µg/L vs. 0.52±0.33 µg/L, respectively - P=0.07), both within the normal range. After RYGB, the simultaneous change in expression of GI genes, may impair carotenoid metabolism in the enterocytes, formation of nascent chylomicrons and transport of retinol, resulting in lower availability of vitamin A.

Genetic reprogramming of remnant duodenum may contribute to type 2 diabetes improvement after Roux-en-Y gastric bypass.

OBJECTIVES: Type 2 diabetes control occurs within a few days after Roux-en-Y gastric bypass (RYGB) and might be related to intestinal adaptation to the new anatomic arrangement. The aim of this study was to evaluate the intestinal transcriptome response to RYGB and its correlation with markers of glycemic homeostasis. METHODS: Global transcriptomic analyses performed by microarray technique were conducted in intestinal biopsies collected from adult women with obesity (N = 20) and T2D before and 3 mo after RYGB. Clinical and biochemical markers of glycemic homeostasis were also evaluated. At 1-y postoperative, patients were classified as responsive (R) or non-responsive (NR) to complete T2D remission according to the American Diabetes Association criteria. Intestinal differentially expressed genes (DEGs) were analyzed separately in the two groups, validated by reverse transcription quantitative polymerase chain reaction, and applied in functional enrichment and canonical pathway analysis. Spearman correlations between clinical and biochemical variables with DEGs were conducted. Twelve patients were classified as R and displayed 62 (duodenum), 241 (jejunum), and 63 (ileum) DEGs. RESULTS: Eight of the patients with DEGs presented very strong or strong positive correlations with glycemia or glycated hemoglobin. Duodenal changes of genes involved in the LXR/RXR pathway were more likely to be associated with T2D. CONCLUSION: In obese women, complete remission of T2D after RYGB might include intestinal transcriptomic changes that suggest a potential role of intracellular cholesterol and lipid homeostasis on glucose control.

Nutritional guidance, monitoring, and supplementation before and after bariatric surgery - Are we doing this correctly?

INTRODUCTION: Background and aims: minimizing nutritional depletions after a Roux-en-Y gastric bypass (RYGB) may improve clinical results in the treatment of obesity. We evaluated nutritional aspects of obese women undergoing RYGB at a reference university hospital with a department specialized in bariatric surgery. Method: based on the Dietary Reference Intakes developed by the Food and Nutrition Council, Institute of Medicine, and the guidelines issued by the American Society for Metabolic and Bariatric Surgery, we assessed the quantitative and qualitative adequacy of nutritional intake, supplementation, and biochemical monitoring of 20 women both before and 3 and 12 months after a RYGB. Data on nutritional intake was obtained by applying different food surveys, quantitatively interpreted by the Virtual Nutri Plus® software and using reference nutritional databases. Results: nutritional intake deficits were already found before the RYGB (p ≤ 0.05). These worsened postoperatively (p ≤ 0.05), a period also marked by a qualitatively poor diet. The nutritional supplementation prescribed did not fully achieve the reference recommendations, and was poorly complied with by patients. Furthermore, nutritional monitoring was not carried out in all patients, recommended biochemical markers were not screened, and vitamin D depletions occurred. Conclusion: our data suggest that institutions specialized in bariatric patient care may not be adequately adhering to well known guidelines, or applying efficient strategies to improve compliance.

INTRODUCCIÓN: Antecedentes y objetivos: minimizar el deterioro nutricional después del baipás gástrico en Y de Roux (BGYR) puede mejorar los resultados clínicos en el tratamiento de la obesidad. Se evaluaron aspectos nutricionales de mujeres obesas sometidas a BGYR en un hospital universitario de referencia con servicio especializado de cirugía bariátrica. Método: con base en la Ingesta Dietética de Referencia desarrollada por el Consejo de Alimentos y Nutrición del Instituto de Medicina, y las directrices de la Sociedad Estadounidense de Cirugía Bariátrica y Metabólica, evaluamos la adecuación cuantitativa y cualitativa de la ingesta nutricional, la suplementación y el seguimiento bioquímico de 20 mujeres tanto antes como 3 y 12 meses después de un BGYR. Los datos de la ingesta nutricional se obtuvieron mediante la aplicación de diferentes encuestas alimentarias, interpretadas cuantitativamente por el software Virtual Nutri Plus® y utilizando bases de datos nutricionales de referencia. Resultados: se encontraron déficits de ingesta nutricional antes del BGYR (p < 0,05). Estos empeoraron en el postoperatorio (p < 0,05), período también marcado por una mala alimentación cualitativa. La suplementación nutricional prescrita no cumplió plenamente con las recomendaciones de referencia y no fue bien cumplida por los pacientes. Además, la monitorización nutricional no se aplicó en todos los pacientes y no se examinaron todos los marcadores bioquímicos recomendados, hallándose depleciones de vitamina D. Conclusión: nuestros datos sugieren que las instituciones especializadas en la atención de pacientes bariátricos podrían no estar siguiendo adecuadamente las pautas recomendadas, ni aplicando estrategias eficientes para mejorar su cumplimiento.

Intestinal expression of toll-like receptor gene changes early after gastric bypass surgery and association with type 2 diabetes remission.

OBJECTIVES: Abnormal activation of toll-like receptors (TLRs) is observed in obese rodents and is correlated with local dysbiosis and increased gut permeability. These purported changes trigger systemic inflammation associated with obesity-related comorbidities, including type 2 diabetes (T2D). Roux-en-Y gastric bypass (RYGB) surgery is an effective treatment for severe obesity and known to induce changes in the gut microbiota and decrease systemic inflammation in humans. This study examined the intestinal expression of TLR-encoding genes in obese women (n = 20) treated with RYGB surgery and the relationship of these genes with T2D remission (T2Dr METHODS: Intestinal biopsies were performed before and 3 months after RYGB surgery. Partial and complete T2Dr after 1 year was assessed using the American Diabetes Association criteria. Affymetrix Human GeneChip 1.0 ST array (microarray) and TaqMan assay (real-time quantitative polymerase chain reaction) were used to analyze intestinal gene expression, and associations with systemic markers of energy homeostasis were examined. RESULTS: Patients experienced significant weight loss (P < 0.001) and altered gut TLR gene expression 3 months after surgery. The main effects were a reduction in jejunal TLR4 expression in patients with complete and partial T2Dr (P < 0.05). There was a postoperative decrease in jejunal TLR7 expression in patients with complete T2Dr that correlated inversely with high-density lipoprotein cholesterol and positively with triglyceride concentrations, but not with weight loss. CONCLUSIONS: RYGB-induced weight loss-independent changes in the expression of intestinal TLR-encoding genes in obese women and complete T2Dr that was correlated with systemic markers of energy homeostasis. The modulation of intestinal TLRs may mediate inflammatory mechanisms linked to T2Dr after RYGB surgery.

Type 2 Diabetes Metabolic Improvement After Roux-en-Y Gastric Bypass May Include a Compensatory Mechanism That Balances Fatty Acid ß and ω Oxidation.

BACKGROUND: More than half of patients who undergo Roux-en-Y gastric bypass (RYGB) can experience type 2 diabetes (T2D) remission, but the systemic and gastrointestinal (GI) metabolic mechanisms of this improvement are still elusive. METHODS: Paired samples collected before and 3 months after RYGB from 28 women with obesity and T2D were analyzed by metabolomics with gas chromatography coupled to mass spectrometry. Samples include plasma (n = 56) and biopsies of gastric pouch (n = 18), gastric remnant (n = 10), duodenum (n = 16), jejunum (n = 18), and ileum (n = 18), collected by double-balloon enteroscopy. RESULTS: After RYGB, improvements in body composition and weight-related and glucose homeostasis parameters were observed. Plasma-enriched metabolic pathways included arginine and proline metabolism, urea and tricarboxylic acid (TCA) cycles, gluconeogenesis, malate-aspartate shuttle, and carnitine synthesis. In GI tissue, we observed alterations of ammonia recycling and carnitine synthesis in gastric pouch, phenylacetate metabolism and trehalose degradation in duodenum and jejunum, ketone bodies in jejunum, and lactose degradation in ileum. Intermediates molecules of the TCA cycle were enriched, particularly in plasma, jejunum, and ileum. Fluctuations of dicarboxylic acids (DCAs) were relevant in several metabolomic tests, and metabolite alterations included aminomalonate and fumaric, malic, oxalic, and succinic acids. The product/substrate relationship between these molecules and its pathways may reflect a compensatory mechanism to balance metabolism. CONCLUSIONS: RYGB was associated with systemic and GI metabolic reprogramming. DCA alterations link ω and ß fatty acid oxidation to homeostatic mechanisms, including TCA cycle improvement.

Gut Microbiota Profile of Obese Diabetic Women Submitted to Roux-en-Y Gastric Bypass and Its Association with Food Intake and Postoperative Diabetes Remission.

Gut microbiota composition is influenced by environmental factors and has been shown to impact body metabolism. OBJECTIVE: To assess the gut microbiota profile before and after Roux-en-Y gastric bypass (RYGB) and the correlation with food intake and postoperative type 2 diabetes remission (T2Dr). DESIGN: Gut microbiota profile from obese diabetic women was evaluated before (n = 25) and 3 (n = 20) and 12 months (n = 14) after RYGB, using MiSeq Illumina-based V4 bacterial 16S rRNA gene profiling. Data on food intake (7-day record) and T2Dr (American Diabetes Association (ADA) criteria) were recorded. RESULTS: Preoperatively, the abundance of five bacteria genera differed between patients with (57%) and without T2Dr (p < 0.050). Preoperative gut bacteria genus signature was able to predict the T2Dr status with 0.94 accuracy ROC curve (receiver operating characteristic curve). Postoperatively (vs. preoperative), the relative abundance of some gut bacteria genera changed, the gut microbial richness increased, and the Firmicutes to Bacteroidetes ratio (rFB) decreased (p < 0.05) regardless of T2Dr. Richness levels was correlated with dietary profile pre and postoperatively, mainly displaying positive and inverse correlations with fiber and lipid intakes, respectively (p < 0.05). CONCLUSIONS: Gut microbiota profile was influenced by RYGB and correlated with diet and T2Dr preoperatively, suggesting the possibility to assess its composition to predict postoperative T2Dr.

Potential premalignant status of gastric portion excluded after Roux en-Y gastric bypass in obese women: A pilot study.

We evaluated whether the excluded stomach (ES) after Roux-en-Y gastric bypass (RYGB) can represent a premalignant environment. Twenty obese women were prospectively submitted to double-balloon enteroscopy (DBE) with gastric juice and biopsy collection, before and 3 months after RYGB. We then evaluated morphological and molecular changes by combining endoscopic and histopathological analyses with an integrated untargeted metabolomics and transcriptomics multiplatform. Preoperatively, 16 women already presented with gastric histopathological alterations and an increased pH (≥4.0). These gastric abnormalities worsened after RYGB. A 90-fold increase in the concentration of bile acids was found in ES fluid, which also contained other metabolites commonly found in the intestinal environment, urine, and faeces. In addition, 135 genes were differentially expressed in ES tissue. Combined analysis of metabolic and gene expression data suggested that RYGB promoted activation of biological processes involved in local inflammation, bacteria overgrowth, and cell proliferation sustained by genes involved in carcinogenesis. Accumulated fluid in the ES appears to behave as a potential premalignant environment due to worsening inflammation and changing gene expression patterns that are favorable to the development of cancer. Considering that ES may remain for the rest of the patient's life, long-term ES monitoring is therefore recommended for patients undergoing RYGB.

Fecal bile acid profile after Roux-en-Y gastric bypass and its association with the remission of type 2 diabetes in obese women: A preliminary study.

OBJECTIVE: To assess the influence of Roux-en-Y gastric by-pass (RYGB) on fecal bile acid (BA) profile and its relationship with postoperative remission of type 2 diabetes (T2D). METHODS: Fecal samples were collected 3 and 12 months after RYGB from diabetic obese women who were responsive (n = 12) and non-responsive (n = 8) to postoperative remission of T2D. Fecal BA profile was accessed by liquid chromatography coupled to tandem mass spectrometry in a targeted approach. RESULTS: Relative to pre-operative levels, a total of 10 fecal BA profiles decreased after RYGB (ANOVA, p ≤ 0.05) with significant fold-changes for glycochenodeoxycholic, glycocholic, taurocholic, and taurochenodeoxycholic acids at 3-months postoperatively, and for glycochenodeoxycholic, glycocholic and taurocholic acids at 12 months postoperatively (Benjamini-Hochberg, p ≤ 0.05). Postoperative changes in fecal BA were different between responsive and non-responsive women, with a significant reduction in more sub-fractions of BA in responsive women than in non-responsive women, and a marked difference in the temporal behavior of cholic acid (CA) and chenodeoxycholic acid (CDCA), thus reflecting changes in CA/CDCA ratio, and tauroursodeoxycolic (TUDCA) levels between these responsiveness groups (ANOVA, p ≤ 0.05). CONCLUSION: RYGB induces a marked reduction in the concentration of fecal BA, which is heterogeneous according to T2D responsiveness.

Reduced intestinal FADS1 gene expression and plasma omega-3 fatty acids following Roux-en-Y gastric bypass.

BACKGROUND & AIMS: Roux-en-Y gastric bypass (RYGB) limits food ingestion and may alter the intestinal expression of genes involved in the endogenous synthesis of polyunsaturated fatty acids (PUFAs). These changes may decrease the systemic availability of bioactive PUFAs after RYGB. To study the impact of RYGB on the dietary ingestion and plasma concentration of PUFAs and on the intestinal expression of genes involved in their endogenous biosynthesis in severely obese women with type 2 diabetes. METHODS: Before, and 3 and 12 months after RYGB, obese women (n = 20) self-reported a seven-day dietary record, answered a food frequency query and provided plasma samples for alpha-linolenic (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic (ARA) acid assessment by gas chromatography. Intestinal biopsies (duodenum, jejunum and ileum) were collected through double-balloon endoscopy before and 3 months after RYGB for gene expression analysis by microarray (Human GeneChip 1.0 ST array) and RT-qPCR validation. RESULTS: Compared to the preoperative period, patients had decreased intakes of PUFAs, fish and soybean oil (p < 0.05) and lower plasma concentrations of ALA and EPA (p < 0.001) 3 and 12 months after RYGB. FADS1 gene expression was lower in duodenum (RT-qPCR fold change = -1.620, p < 0.05) and jejunum (RT-qPCR fold change = -1.549, p < 0.05) 3 months following RYGB, compared to before surgery. CONCLUSION: RYGB decreased PUFA ingestion, plasma ALA and EPA levels, and intestinal expression of FADS1 gene. The latter encodes a key enzyme involved in endogenous biosynthesis of PUFAs. These data suggest that supplementation of omega-3 PUFAs may be required for obese patients undergoing RYGB. Clinical Trial Registry number and website: www.clinicaltrials.gov - NCT01251016; Plataforma Brasil - 19339913.0.0000.0068.

A new anthropometric index for body fat estimation in patients with severe obesity.

BACKGROUND: Body mass index (BMI) has been used to assess body adiposity, but it cannot adequately reflect body fat (BF) amount. The body adiposity index (BAI) has been shown a better performance than BMI for this purpose, but it can be inaccurate to estimate BF under extreme amounts of fat. Here, we propose a new anthropometric index, the Belarmino-Waitzberg (BeW) index, for specific estimation of BF in severely obese patients. METHODS: In 144 adult patients with severe obesity, BF was estimated by air displacement plethysmography (ADP), as the reference method, along with the follow anthropometric measurements: height, abdominal circumference (AC), hip circumference (HC), weight, BMI (weight/ height2) and BAI ([HC(cm) / height (m)1.5) - 18] × 100). Patients were proportionately distributed into two distinct databases, the building model database (BMD) and the validation model database (VMD), which were applied to develop and validate the BeW index, respectively. The BeW index was tested for gender and ethnicity adjustment as independent variables. The agreement of BF% values obtained by the new index and by BAI with ADP was also assessed. RESULTS: The BF% was 52.05 ± 5.42 for ADP and 59.11 ± 5.95 for the BeW index (all results are expressed as the mean ± standard deviation). A positive Pearson correlation (r = 0.74), a good accuracy (Cb = 0.94), and a positive Lin's concordance correlation (CCC = 0.70) were observed between the two groups. The 95% limits of individual agreement between the BeW index and ADP were 6.8 to 7.9%, compared to - 7.5 to 14.8% between the BAI and ADP. The new index, called the Belarmino-Waitzberg (BeW) index, showed an improvement of 2.1% for the R2 value and a significant gender effect, therefore resulting in two different indexes for females and males, as follows: Female BeW = - 48.8 + 0.087 × AC(cm) + 1.147 × HC(cm) - 0.003 × HC(cm)2 and Male BeW = - 48.8 + 0.087 × AC(cm) + 1.147 × HC(cm) - 0.003 × HC(cm)2-7.195. CONCLUSIONS: The new BeW index showed a good performance for BF estimation in patients with severe obesity and can be superior to the BAI for this purpose.

Bariatric surgery and gene expression in the gut.

PURPOSE OF REVIEW: The current review provides an overview of recent literature on new findings related to bariatric surgery and gut gene expression. RECENT FINDINGS: Bariatric surgery modulates the expression of intestinal genes. Experimental and clinical investigations have demonstrated the association of gut rearrangement with changes in intestinal expression of genes related to glucose metabolism. Recent data suggest that bariatric surgery also affects expression of genes belonging to other pathways, including nutrient transporters and metabolism of vitamin B12, decreasing pathway-encoding genes that may contribute to vitamin B12 deficiency in the postoperative period. SUMMARY: Bariatric surgery is an effective intervention strategy against severe obesity, resulting in sustained weight loss and reduction of comorbidities. Nutritional genomic changes appear in response to bariatric surgery, possibly due to adaptive gut response. Improved understanding of the molecular pathways modulated by this intervention may facilitate weight and comorbidities management.

Upregulation of Ghrelin Gene Expression in the Excluded Stomach of Obese Women with Type 2 Diabetes After Roux-en-Y Gastric Bypass in the SURMetaGIT Study.

BACKGROUND: Mechanisms of type 2 diabetes remission (T2Dr) after Roux-en-Y gastric bypass (RYGB) in obese patients appear to involve gastrointestinal hormones. OBJECTIVE: The objective of this study is to explore changes in ghrelin plasma levels and ghrelin gastrointestinal gene expression (GHRL) after RYGB, and their relationships to T2Dr. SETTING: In 20 obese women with T2D, before and 3 months after RYGB, we assessed GHRL expression by microarray and quantitative RT-PCR in gastrointestinal biopsy samples and plasma levels of ghrelin. RESULTS: After RYGB, GHRL expression increased in the excluded stomach (p < 0.05) with no change in other gastrointestinal sites. There were no significant changes in ghrelin plasma levels and no correlations with T2Dr. CONCLUSIONS: After RYGB, over-expression of GHRL gene occurs only in the excluded stomach with no correlation to T2Dr.

Diagnosing Sarcopenia in Male Patients With Cirrhosis by Dual-Energy X-Ray Absorptiometry Estimates of Appendicular Skeletal Muscle Mass.

BACKGROUND: Ascites in cirrhotic patients interfere with accurate assessment of skeletal muscle when diagnosing sarcopenia. We hypothesized measurement of appendicular skeletal muscle index (ASMI) with dual-energy x-ray absorptiometry (DXA) improves the diagnosis of sarcopenia in cirrhotic patients as ASMI does not include the fluid-filled abdominal compartment. OBJECTIVE: To evaluate if ASMI is influenced by ascites, lower limb edema (LLE) and predicts mortality alone or combined with handgrip strength (HGS) in cirrhotic patients. DESIGN: ASMI, HGS, and 36-month mortality were obtained in 144 men with cirrhosis. ASMI was compared before and after paracentesis in 20 men with ascites and to results from 20 matched controls. The prognostic value of ASMI alone and with HGS was tested in a survival. Survival probabilities were obtained for sarcopenia diagnosed by standard ASMI and HGS European Working Group on Sarcopenia in Older People (EWGSOP) cutoffs and a new cutoff calculated from our ASMI + HGS tertiles. RESULTS: ASMI did not change after paracentesis, was lower in patients than in controls (P < .001), and was not influenced by LLE (D = 0.30 kg/m2, P = .068; R2 = 2.40%). Mortality was influenced by ASMI and HGS (Pinteraction = 0.028). Sarcopenia diagnosed by EWGSOP was also diagnosed by our new cutoff; both predicted mortality with the latter more sensitive for mortality risk prediction (P = .011). CONCLUSIONS: DXA-measured ASMI is not influenced by ascites or LLE in cirrhotic patients; can diagnose low skeletal muscle/sarcopenia; and predicts mortality, particularly when combined with HGS.

Prebiotic and Synbiotic Modifications of Beta Oxidation and Lipogenic Gene Expression after Experimental Hypercholesterolemia in Rat Liver.

Background and aims: Non-alcoholic fatty liver disease (NAFLD) is characterized by the presence of fat in hepatocytes because of decreased ß-oxidation and increased lipogenesis. Prebiotics, probiotics, and synbiotic have modulatory effects on intestinal microbiota and may influence the gut-liver axis. Our aim was to evaluate the effects of prebiotic, probiotics, and synbiotic on liver histopathology and gene expression related to ß-oxidation and lipogenesis after hypercholesterolemia. Methods: Wistar male adult rats (n = 40) were submitted to hypercholesterolemic conditions (HPC) (60 days). On Day 30 of HPC, rats were subdivided in 5 groups: negative control (NC): without HPC + Gv (distilled water); positive control (PC): with HPC + Gv (distilled water); prebiotic (PRE): HPC + Gv with prebiotic (Fiber FOS®); probiotic (PRO): HPC + Gv with probiotic strains Gv (Probiatop®); and synbiotic (SYN): HPC + Gv with synbiotic (Simbioflora®). All rats were sacrificed on Day 30 post-treatment. Blood was collected to verify total serum cholesterol, and liver tissue was sampled to verify histopathological changes and gene expression. Gene expression related to ß-oxidation (PPAR-α and CPT-1) and lipogenesis (SREBP-1c, FAS and ME) was evaluated in liver tissue using RT-qPCR. Results: PC had higher cholesterol levels when compared to NC. PRE and SYN rats had lower cholesterol levels than PC. PC rats showed more histopathological changes than NC rats; PRE and SYN rats showed fewer alterations than PC rats. PPAR-α was expressed at higher levels in SYN and PC rats compared with PRE and PRO rats. CPT-1 expression was similar in all groups. SREBP-1c was expressed at higher levels in PC rats compared with NC rats; levels were lower in SYN rats compared with PRO rats; levels were lower in PRE rats compared with PC and PRO rats. FAS was expressed at lower levels in PRE rats compared with SYN rats. ME expression was lower in PC rats compared with NC rats. Conclusion: Prebiotic and synbiotic supplementation improve hepatic alterations related to hypercholesterolemia. These changes appear to be mediated by altered expression of genes related to ß-oxidation and lipogenesis.

Tissue-specific methylation profile in obese patients with type 2 diabetes before and after Roux-en-Y gastric bypass.

Eating habits, lifestyles, and exposure to specific environmental factors can greatly impact the risk of developing type 2 diabetes (T2D), influence the genome epigenetically, and affect the expression of genes, including genes related to glycemic control, at any stage of life. The epigenetic mechanism underlying obesity and T2D pathogenesis remains poorly understood. Conventional strategies for the treatment of obesity and its comorbidities often have poor long-term adherence, and pharmacological interventions are limited. Bariatric surgery is the most effective current option to treat severe obesity, and Roux-en-Y gastric bypass (RYGB) is the most applied technique worldwide. Epigenetic changes differ depending on the approach used to treat obesity and its associated comorbidities (clinical or surgical). Compared to primary clinical care, bariatric surgery leads to much greater loss of body weight and higher remission rates of T2D and metabolic syndrome, with methylation profiles in promoter regions of genes in obese individuals becoming similar to those of normal-weight individuals. Bariatric surgery can influence DNA methylation in parallel with changes in gene expression pattern. Changes in clinical biomarkers that reflect improvements in glucose and lipid metabolism after RYGB often occur before major weight loss and are coordinated by surgery-induced changes in intestinal hormones. Therefore, the intestine methylation profile would assist in understanding the mechanisms involved in improved glycemic control after bariatric surgery. The main objectives in this area for the future are to identify epigenetic marks that could be used as early indicators of metabolic risk, and to develop treatments able to delay or even reverse these epigenetic changes. Studies that provide the "human epigenetic profile" will be of considerable value to identify tissue-specific epigenetic signatures and their role in the development of chronic diseases. Further studies should apply methods based on global analysis of the genome to identify methylated sites associated with disease and epigenetic marks associated with the remodeling response to bariatric surgery. This review describes the main epigenetic alterations associated with obesity and T2D and the potential role of RYGB in remodeling these changes.

Phase angle obtained by bioelectrical impedance analysis independently predicts mortality in patients with cirrhosis.

AIM: To evaluate the prognostic value of the phase angle (PA) obtained from bioelectrical impedance analysis (BIA) for mortality prediction in patients with cirrhosis. METHODS: In total, 134 male cirrhotic patients prospectively completed clinical evaluations and nutritional assessment by BIA to obtain PAs during a 36-mo follow-up period. Mortality risk was analyzed by applying the PA cutoff point recently proposed as a malnutrition marker (PA ≤ 4.9°) in Kaplan-Meier curves and multivariate Cox regression models. RESULTS: The patients were divided into two groups according to the PA cutoff value (PA > 4.9°, n = 73; PA ≤ 4.9°, n = 61). Weight, height, and body mass index were similar in both groups, but patients with PAs > 4.9° were younger and had higher mid-arm muscle circumference, albumin, and handgrip-strength values and lower severe ascites and encephalopathy incidences, interleukin (IL)-6/IL-10 ratios and C-reactive protein levels than did patients with PAs ≤ 4.9° (P ≤ 0.05). Forty-eight (35.80%) patients died due to cirrhosis, with a median of 18 mo (interquartile range, 3.3-25.6 mo) follow-up until death. Thirty-one (64.60%) of these patients were from the PA ≤ 4.9° group. PA ≤ 4.9° significantly and independently affected the mortality model adjusted for Model for End-Stage Liver Disease score and age (hazard ratio = 2.05, 95%CI: 1.11-3.77, P = 0.021). In addition, Kaplan-Meier curves showed that patients with PAs ≤ 4.9° were significantly more likely to die. CONCLUSION: In male patients with cirrhosis, the PA ≤ 4.9° cutoff was associated independently with mortality and identified patients with worse metabolic, nutritional, and disease progression profiles. The PA may be a useful and reliable bedside tool to evaluate prognosis in cirrhosis.

Type 2 Diabetes Remission After Roux-en-Y Gastric Bypass: Evidence for Increased Expression of Jejunal Genes Encoding Regenerating Pancreatic Islet-Derived Proteins as a Potential Mechanism.

BACKGROUND: Intestinal expression of regenerating pancreatic islet-derived protein-encoding genes (REG) would be enhanced after Roux-en-Y gastric bypass (RYGB) and would affect postoperative type 2 diabetes remission (T2Dr). METHODS: Intestinal biopsy samples were collected from 20 adult obese women with T2D before and 3 months after RYGB. Levels of REG expression and the gene encoding its putative receptor (EXTL3) were assessed by microarray and validated by quantitative RT-PCR. T2Dr was assessed according to ADA criteria 1 year after RYGB. RESULTS: After RYGB, only patients with T2Dr had significantly increased REG1α and REG3γ expression in the jejunum, as validated by quantitative RT-PCR. CONCLUSIONS: Our data provide support for the hypothesis that increased jejunal expression of REG genes after RYGB affects T2Dr, possibly by playing an endocrine function.

Gastrointestinal Transcriptomic Response of Metabolic Vitamin B12 Pathways in Roux-en-Y Gastric Bypass.

OBJECTIVES: Vitamin B12 (B12) deficiency after Roux-en-Y gastric bypass (RYGB) is highly prevalent and may contribute to postoperative complications. Decreased production of intrinsic factor owing to gastric fundus removal is thought to have a major role, but other components of B12 metabolism may also be affected. We evaluated changes in the expression levels of multiple B12 pathway-encoding genes in gastrointestinal (GI) tissues to evaluate the potential roles in contributing to post-RYGB B12 deficiency. METHODS: During double-balloon enteroscopy, serial GI biopsies were collected from 20 obese women (age, 46.9±6.2 years; body mass index, 46.5±5.3 kg/m2) with adult-onset type 2 diabetes (fasting plasma glucose ≥126 mg/dl; hemoglobin A1c≥6.5%) before and, at the same site, 3 months after RYGB. Gene expression levels were assessed by the Affymetrix Human GeneChip 1.0 ST microarray. Findings were validated by real-time quantitative PCR (RT-qPCR). RESULTS: Gene expression levels with significant changes (P≤0.05) included: transcobalamin I (TCN1) in remnant (-1.914-fold) and excluded (-1.985-fold) gastric regions; gastric intrinsic factor (GIF) in duodenum (-0.725-fold); and cubilin (CUBN) in duodenum (+0.982-fold), jejunum (+1.311-fold), and ileum (+0.685-fold). Validation by RT-qPCR confirmed (P≤0.05) observed changes for TCN1 in the remnant gastric region (-0.132-fold) and CUBN in jejunum (+2.833-fold). CONCLUSIONS: RYGB affects multiple pathway-encoding genes that may be associated with postoperative B12 deficiency. Decreased TCN1 levels seem to be the main contributing factor. Increased CUBN levels suggest an adaptive genetic reprogramming of intestinal tissue aiming to compensate for impaired intestinal B12 delivery.