Obesity and polycystic ovary syndrome influence on intestinal permeability at fasting, and modify the effect of diverse macronutrients on the gut barrier.

Women with the extremely prevalent polycystic ovary syndromegather multiple cardiovascular risk factors and chronic subclinical inflammation. Interactions between diet, adiposity, and gut microbiota modulate intestinal permeabilityand bacterial product translocation, and may contribute to the chronic inflammation process associated with the polycystic ovary syndrome. In the present study, we aimed to address the effects of obesity, functional hyperandrogenism, and diverse oral macronutrients on intestinal permeabilityby measuring circulating markers of gut barrier dysfunction and endotoxemia. Participants included 17 non-hyperandrogenic control women, 17 women with polycystic ovary syndrome, and 19 men that were submitted to glucose, lipid, and protein oral loads. Lipopolysaccharide-binding protein, plasma soluble CD14, succinate, zonulin family peptide, and glucagon-like peptide-2 were determined at fasting and after oral challenges. Macronutrient challenges induced diverse changes on circulating intestinal permeabilitybiomarkers in the acute postprancial period, with lipids and proteins showing the most unfavorable and favorable effects, respectively. Particularly, lipopolysaccharide-binding protein, zonulin family peptide, and glucagon-like peptide-2 responses were deregulated by the presence of obesity after glucose and lipid challenges. Obese subjects showed higher fasting intestinal permeabilitybiomarkers levels than non-obese individuals, except for plasma soluble CD14. The polycystic ovary syndromeexacerbated the effect of obesity further increasing fasting glucagon-like peptide-2, lipopolysaccharide-binding protein, and succinate concentrations. We observed specific interactions of the polycystic ovary syndromewith obesity in the postprandial response of succinate, zonulin family peptide, and glucagon-like peptide-2. In summary, obesity and polycystic ovary syndromemodify the effect of diverse macronutrients on the gut barrier, and alsoinfluence intestinal permeabilityat fasting,contributing to the morbidity of functional hyperandrogenism by inducing endotoxemia and subclinical chronic inflammation.

GIP and GLP-2 together improve bone turnover in humans supporting GIPR-GLP-2R co-agonists as future osteoporosis treatment.

The intestinal hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are key regulators of postprandial bone turnover in humans. We hypothesized that GIP and GLP-2 co-administration would provide stronger effect on bone turnover than administration of the hormones separately, and tested this using subcutaneous injections of GIP and GLP-2 alone or in combination in humans. Guided by these findings, we designed series of GIPR-GLP-2R co-agonists as template for new osteoporosis treatment. The clinical experiment was a randomized cross-over design including 10 healthy men administered subcutaneous injections of GIP and GLP-2 alone or in combination. The GIPR-GLP-2R co-agonists were characterized in terms of binding and activation profiles on human and rodent GIP and GLP-2 receptors, and their pharmacokinetic (PK) profiles were improved by dipeptidyl peptidase-4 protection and site-directed lipidation. Co-administration of GIP and GLP-2 in humans resulted in an additive reduction in bone resorption superior to each hormone individually. The GIPR-GLP-2R co-agonists, designed by combining regions of importance for cognate receptor activation, obtained similar efficacies as the two native hormones and nanomolar potencies on both human receptors. The PK-improved co-agonists maintained receptor activity along with their prolonged half-lives. Finally, we found that the GIPR-GLP-2R co-agonists optimized toward the human receptors for bone remodeling are not feasible for use in rodent models. The successful development of potent and efficacious GIPR-GLP-2R co-agonists, combined with the improved effect on bone metabolism in humans by co-administration, support these co-agonists as a future osteoporosis treatment.

Alteration of Intestinal Microbiota in 3-Deoxyglucosone-Induced Prediabetic Rats.

Our previous research suggests that 3-deoxyglucosone (3DG), formed in the caramelization course and Maillard reactions in food, is an independent factor for the development of prediabetes. Since the relationship between type 2 diabetes (T2D) and intestinal microbiota is moving from correlation to causality, we investigated the alterations in the composition and function of the intestinal microbiota in 3DG-induced prediabetic rats. Rats were given 50 mg/kg 3DG by intragastric administration for two weeks. Microbial profiling in faeces samples was determined through the 16S rRNA gene sequence. The glucagon-like peptide 2 (GLP-2) and lipopolysaccharide (LPS) levels in plasma and intestinal tissues were measured by ELISA and Limulus test, respectively. 3DG treatment did not significantly change the richness and evenness but affected the composition of intestinal microbiota. At the phylum level, 3DG treatment increased the abundance of nondominant bacteria Proteobacteria but did not cause the change of the dominant bacteria. Meanwhile, the abundance of the Prevotellaceae family and Parasutterela genus and the Alcaligencaeae family and Burkholderiales order and its attachment to the Betaproteobacteria class were overrepresented in the 3DG group. The bacteria of Candidatus Soleaferrea genus, Gelria genus, and Thermoanaerobacteraceae family and its attachment to Thermoanaerobacterales order were apparently more abundant in the control group. In addition, 45 KEGG pathways were altered after two-week intragastric administration of 3DG. Among these KEGG pathways, 13 KEGG pathways were involved in host metabolic function related to amino acid metabolism, carbohydrate metabolism, metabolism of cofactors and vitamins, and metabolism of terpenoids and polyketides. Moreover, the increased LPS levels and the decreased GLP-2 concentration in plasma and intestinal tissues were observed in 3DG-treated rats, together with the impaired fasting glucose and oral glucose tolerance. The alterations in composition and function of the intestinal microbiota were observed in 3DG-treated rats, which provides a possible mechanism linking exogenous 3DG intake to the development of prediabetes.

Feeding colostrum or a 1:1 colostrum:milk mixture for 3 days postnatal increases small intestinal development and minimally influences plasma glucagon-like peptide-2 and serum insulin-like growth factor-1 concentrations in Holstein bull calves.

This study evaluated how feeding colostrum- or a colostrum-milk mixture for 3 d postnatal affects plasma glucagon-like peptide-2 (GLP-2), serum insulin-like growth factor-1 (IGF-1), and small intestinal histomorphology in calves. Holstein bulls (n = 24) were fed colostrum at 2 h postnatal and randomly assigned to receive either colostrum (COL), whole milk (WM), or a 1:1 COL:WM mixture (MIX) every 12 h from 12 to 72 h. A jugular venous catheter was placed at 1 h postnatal to sample blood frequently for the duration of the experiment. Samples were collected at 1, 2, 3, 6, 9, 11, and 12 h. Following the 12-h meal, blood was collected at half-hour intervals until 16 h and then at 1-h intervals from 16 to 24 h. A 27-h sample was taken, then blood was sampled every 6 h from 30 to 60 h. Again, blood was taken at half-intervals from 60 to 64 h, then at 65 and 66 h, following which, a 2-h sampling interval was used until 72 h. Plasma GLP-2 (all time points) and serum IGF-1 (at time points: 1, 6, 12, 18, 24, 36, 48, and 72 h) were both analyzed. Duodenal, jejunal, and ileal tissues were collected at 75 h of age to assess histomorphology and cellular proliferation. Feeding COL, rather than WM, increased plasma GLP-2 by 60% for 2 h and tended to increase GLP-2 by 49.4% for 4 h after the 60-h meal. Insulin-like growth factor-1 area under the curve (from 12 to 72 h) tended to be 27% greater for COL than WM calves but was otherwise unaffected by treatment. Ileal crypts tended to proliferate more with MIX than WM, whereas ileal crypt proliferation did not differ for COL compared with MIX or WM and was not different between treatments in the proximal jejunum. Villi height was increased 1.8 and 1.5× (COL and MIX vs. WM) in the proximal and distal jejunum, respectively, whereas MIX duodenal and ileal villi height tended to be 1.5 and 1.4× that of WM. Crypt depth did not differ in any region. Surface area of the gastrointestinal tract was reduced for WM by 60 and 58% (proximal jejunum) and 38 and 52% (ileum) relative to COL and MIX and was 54% less than MIX in the distal jejunum. Overall, extended COL feeding minimally increased plasma GLP-2 and serum IGF-1 compared with WM feeding. As COL and MIX similarly promoted small intestinal maturation, feeding calves transition milk to promote intestinal development could be a strategy for producers.

Potentiation of Glucagon-Like Peptide-2 Dynamics by Methotrexate Administration in Rat Small Intestine.

The aim of this study was to clarify the relationship between chemotherapy-induced mucositis and endogenous glucagon-like peptide-2 (GLP-2) dynamics in the small intestine following treatment with either methotrexate or 5-fluorouracil. Rats were injected intraperitoneally with a single dose of either 50 mg/kg methotrexate or 100 mg/kg 5-fluorouracil. At 24 and 72 h after drug administration, ileal tissues and plasma were used to investigate GLP-2 dynamics. Administration of methotrexate caused moderate but not significant intestinal injury within 72 h, while administration of 5-fluorouracil caused severe injury in a time-dependent manner. Methotrexate significantly increased proglucagon mRNA expression and the number of anti-GLP-2 antibody-positive cells in the ileal tissue at 24 h after administration. Methotrexate also significantly induced GLP-2 receptor, insulin-like growth factor-1 (IGF-1), and transforming growth factor-ß2 (TGF-ß2) mRNA expression in ileal tissue. In contrast, 5-fluorouracil significantly inhibited proglucagon, GLP-2 receptor, IGF-1, and TGF-ß2 mRNA expression as well as the number of anti-GLP-2 antibody-positive cells. Methotrexate slightly increased dipeptidyl peptidase IV (DPP-4) mRNA expression, whereas 5-fluorouracil significantly increased DPP-4 mRNA expression. These results suggest that potentiation of endogenous GLP-2 dynamics by methotrexate is associated with a mechanism that preserves gastrointestinal mucosal integrity at a moderate level.

Glucagon-like peptide 1 and Glucagon-like peptide 2 in relation to osteoporosis in non-diabetic postmenopausal women.

Osteoporosis results from an imbalance in bone remodeling, which is known to follow a circadian rhythm determined by a functional relationship between intestine and bone tissue. Specific intestinal peptides have been identified as mediators. Glucagon-like peptide 1 and glucagon-like peptide 2, have been associated with bone health. Our main objective was to determine whether postprandial plasma levels of glucagon-like peptide 1, glucagon-like peptide 2 and dipeptidyl-peptidase 4 activity, are associated with osteoporosis in non-diabetic postmenopausal women. We studied non-diabetic postmenopausal women with osteoporosis diagnosed by dual-energy X-ray absorptiometry (cases, n = 43) and age-matched (±1 yr) controls without osteoporosis or a history of osteoporotic fracture (n = 43). We measured postprandial plasma levels of glucagon-like peptide 1, glucagon-like peptide 2, and dipeptidyl-peptidase 4 activity, bone mineral density, and baseline levels of bone remodeling markers and analyzed the food intake using a food-frequency questionnaire. Postprandial glucagon-like peptide 1 values were lower (p < 0.001) in cases, µ (SEM) = 116.25 (2.68), than in controls, µ (SEM) = 126.79 (2.68). Glucagon-like peptide 1 was associated with reduced osteoporosis risk in the crude logistic regression analysis [OR (95% CI) = 0.724 (0.53-0.97), p = 0.031] and adjusted analysis [OR = 0.603 (0.38-0.94), p = 0.027]. We found no association of glucagon-like peptide 2, or dipeptidyl-peptidase 4 activity with osteoporosis. Postprandial glucagon-like peptide 1 levels are related to osteoporosis and osteoporosis risk in non-diabetic postmenopausal women. Further studies are required to verify these findings.

Increased intestinal permeability in patients with short bowel syndrome is not affected by parenteral nutrition.

The aim of our study was to assess the presence and degree of intestinal leakage in subjects suffering from short bowel syndrome (SBS) and its modification by parenteral nutrition. To this end we assessed circulating levels of selected makers of intestinal permeability including zonulin, fatty acid binding protein 2 (FABP-2), citrulline and glucagon-like peptide 2 (GLP-2). We also measured lipopolysaccharide binding protein (LBP) as a marker of circulating levels of lipopolysaccharide acting through the CD14 molecule. Eleven SBS and 10 age- and BMI-matched control subjects were included into the study. The effect of parenteral nutrition was assessed after 14 days, 6 and 12 months from its initiation, respectively. At baseline, SBS patients had increased gut permeability as measured by zonulin (47.24+/-2.14 vs. 39.48+/-1.20 ng/ml, p=0.006) and LBP (30.32+/-13.25 vs. 9.77+/-0.71 microg/ml, p<0.001) compared to healthy controls. Furthermore, SBS subjects had reduced FABP-2, unchanged citrulline and increased sCD14 and GLP-2 relative to control group. Throughout the whole study period the administered parenteral nutrition had no significant effect on any of the studied parameters. Taken together, our data show that patients with short bowel syndrome have increased intestinal permeability that is not affected by parenteral nutrition.

The effect of tributyrin supplementation to milk replacer on plasma glucagon-like peptide 2 concentrations in pre-weaning calves.

The objective of this study was to evaluate the effect of tributyrin (TB) supplementation to milk replacer (MR) on performance, health, and blood concentrations of metabolite and glucagon-like peptide (GLP-2) in pre-weaning calves. Twenty Holstein heifer calves were raised on an intensified nursing program using MR supplemented with either palm oil (CON) or TB (TB) at 0.3% (as fed basis) for 7 weeks starting 1 week after birth. Calves were fed a calf starter and kleingrass from the beginning of the study. Blood samples were obtained weekly to measure blood glucose, serum ß-hydroxybutyric acid (BHBA), insulin-like growth factor 1 (IGF-1), and plasma GLP-2 concentrations. Starter DMI and metabolizable energy (ME) intake were lower in TB calves at 46, 47, from 49 to 55 days after birth compared with the CON calves. However, any growth parameters were not affected by TB treatment. Blood glucose, serum BHBA, and IGF-1 concentrations were not affected by TB supplementation. On the other hand, mean plasma GLP-2 concentration among whole experimental period was higher for TB (0.60 ng/ml) compared with CON (0.41 ng/ml). In conclusion, feeding MR supplemented with TB increases plasma GLP-2 concentration, which might counterbalance the growth performance of TB calves despite the decreased ME intake.

SGL5213, a novel and potent intestinal SGLT1 inhibitor, suppresses intestinal glucose absorption and enhances plasma GLP-1 and GLP-2 secretion in rats.

Sodium-glucose cotransporter 1 (SGLT1) is the primary transporter for glucose absorption from digested nutrients in the gastrointestinal tract. Intestinal SGLT1 inhibition reduces post-prandial hyperglycemia and enhances the increase of plasma glucagon-like peptide-1 (GLP-1) levels. SGL5213 is a novel and potent intestinal SGLT1 inhibitor. This study characterizes the pharmacological profiles of SGL5213 in rodents. Orally administered SGL5213 was hardly absorbed and its distribution was restricted to the gastrointestinal lumen. SGL5213 significantly improved post-prandial hyperglycemia in streptozotocin (STZ)-induced diabetic rats at doses of 1 mg/kg or more. After the oral administration of starch, SGL5213 increased the amount of residual glucose in the small intestine at 1-3 h and in the cecum and colon at 3-9 h by inhibiting glucose absorption and allowing the unabsorbed glucose to be delivered into the lower-gastrointestinal tract. In the vehicle group, the plasma total GLP-1 (tGLP-1) and tGLP-2 levels increased at 15 min and the plasma total glucose-dependent insulinotropic polypeptide (tGIP) level increased at 1 h after meal loading. SGL5213 at doses of 0.1 mg/kg or more enabled the plasma levels of tGLP-1 and tGLP-2 to be retained for a period of 1-6 h, compared with the vehicle group. In contrast, SGL5213 at doses of 0.3 mg/kg or more suppressed the plasma tGIP elevation after meal loading. This study demonstrated for the first time that an intestinal SGLT1 inhibitor enhanced post-prandial plasma GLP-2 secretion. These results suggest that SGL5213 might exhibit a useful pharmacological efficacy through the physiological actions of GLP-1 and GLP-2.

Effects of pulse-dose ruminal infusion of butyrate on plasma glucagon-like peptide 1 and 2 concentrations in dairy calves.

Feeding of butyrate was found to have a positive effects in enhancing gut development and improving growth performance of calves. Equally, glucagon-like peptide 1 and 2 (GLP-1 and GLP-2), secreted from gastrointestinal L-cells in response to nutrient intake, were found to play a significant role in regulating blood glucose homeostasis and improving gut health. However, limited information is available about the relationship between butyrate and release of GLP-1 and GLP-2 in dairy calves. The objective of this study was to evaluate the effects of a pulse-dose ruminal infusion of butyrate on plasma GLP-1 and GLP-2 concentrations in dairy calves. Five ruminally cannulated mature Holstein bull calves (7.2 ± 0.10 mo, and 330 ± 16.0 kg of body weight; mean ± standard deviation) were used in a 5 × 5 Latin square with 4-d periods. On d 1 of each period at 0800 h, calves were ruminally infused with 1 of 5 treatments: 0 (saline), 0.3, 0.6, 0.9, and 1.2 g of butyrate per kg of body weight. Before butyrate infusion, calves were not offered feed overnight, and sequential blood and rumen fluid samples were taken before and after infusion on d 1 of each period. Ruminal butyrate and total volatile fatty acid concentrations increased linearly (2.65, 12.19, 20.99, 30.19, and 36.30; 23.68, 33.07, 40.94, 51.13, and 56.31 µmol/mL, for butyrate and total volatile fatty acids, respectively) in a dose-dependent manner, whereas propionate and isobutyrate increased quadratically. Ruminal and plasma butyrate, ß-hydroxybutyrate, GLP-1, GLP-2, insulin, and glucose concentrations were all affected by treatment, time (except GLP-2), and interaction of treatment with time (except GLP-1). The area under the curve (AUC) summarized at different time points relative to the baseline (AUC30, AUC60, AUC120, and AUC240) for ruminal and plasma butyrate, and BHB, increased linearly with the dose of butyrate infused. However, AUC30, AUC60, AUC120, and AUC240 for plasma GLP-2 concentration were affected in a cubic manner unlike the linear effect on AUC30 and AUC60 for GLP-1. Plasma GLP-2 was not correlated with plasma butyrate (r = 0.16), GLP-1 (r = 0.03), or BHB (r = -0.05). This findings suggest that pulse-dosing of butyrate slightly increased both GLP-1 and GLP-2 concentrations at specific time points and this might be promoted by direct or indirect effect of butyrate on the intestinal L-cells.

The effects of feeding more milk on periprandial plasma glucagon-like peptide-2 concentrations in preweaning dairy calves.

The objective of this study was to evaluate periprandial plasma concentrations of glucagon-like peptide-2 (GLP-2), glucose, and ß-hydroxybutyrate (BHB) in response to a milk meal in preweaning dairy calves. Nineteen Holstein heifer calves were fed either a high (10 L/d; n = 9) or low (5 L/d; n = 10) amount of pasteurized whole milk from d 2 to 50 of life. Calves were housed in individual pens for the first 19 ± 3 d and fed only milk before being moved to a group pen, where they remained on their respective milk treatment and offered calf starter ad libitum. Blood samples were collected sequentially for 240 min following their milk meal at wk 3, 5, and 7 of life to characterize the periprandial response in plasma concentrations of GLP-2, glucose, and BHB. Baseline plasma glucose concentrations were increased, when a high amount was fed; however, we found no difference in area under the curve. Feeding a high amount of whole milk had no effect on baseline or periprandial plasma BHB concentrations. Baseline plasma GLP-2 concentrations decreased as calves aged. Feeding a high amount of whole milk tended to significantly increase baseline GLP-2 concentrations throughout compared with calves fed a low amount. The periprandial response of GLP-2 was not biphasic until calves were 7 wk old. In conclusion, feeding a high amount of milk may increase GLP-2 concentrations in preweaning calves, although its exact mechanism is unknown.

Short communication: The effect of delayed colostrum feeding on plasma concentrations of glucagon-like peptide 1 and 2 in newborn calves.

Glucagon-like peptide (GLP)-1 is involved in glucose homeostasis via its role in stimulating insulin secretion, whereas GLP-2 increases mucosal growth of the small intestine. To our knowledge, the effect of delayed colostrum feeding on plasma GLP-1 and GLP-2 in neonatal calves has not been evaluated. To investigate the effect of delayed colostrum feeding on plasma concentrations of GLP-1 and GLP-2 in newborn calves, we randomly assigned 27 Holstein bull calves to 1 of 3 treatment groups: those fed colostrum within 1 h after birth (control), 6 h after birth (6H), and 12 h after birth (12H; n = 9 for each treatment). Blood samples were obtained before the colostrum feeding and every 3 h after each colostrum feeding for a 36-h period, and plasma concentrations of GLP-1, GLP-2, insulin, and glucose were measured. Plasma GLP-1 concentration at 12 h after colostrum feeding was lower in 12H than in control calves. In addition, plasma insulin concentration was lower in the 6H and 12H calves than in the controls. Plasma glucose and GLP-2 concentrations were, however, not affected by treatment. These results indicate that delayed colostrum feeding can decrease plasma GLP-1 and insulin concentrations without affecting glucose or GLP-2 concentration.

COMPARISON OF THE LEVELS OF C-REACTIVE PROTEIN, GLP-1 AND GLP-2 AMONG INDIVIDUALS WITH DIABETES, MORBID OBESITY AND HEALTHY CONTROLS: AN EXPLORATORY STUDY.

BACKGROUND: The glucagon-like peptides 1 and 2 (GLP-1/GLP-2) are gut hormones that may directly affect the glucose homeostasis and their activity seems to be significantly affected by chronic inflammation. OBJECTIVE: To evaluate the postprandial levels of glucagon-like peptides 1 and 2 (GLP-1/GLP-2), C-reactive protein (CRP), and the postprandial glucose and insulin levels among individuals with obesity, type 2 diabetes, and healthy controls. METHODS: An exploratory cross-sectional study, which involved individuals awaiting for bariatric/metabolic surgery and healthy controls. Postprandial levels of GLP-1, GLP-2, glucose, and insulin were obtained after a standard meal tolerance test. Inflammation was assessed by means of CRP. RESULTS: There were 30 individuals enrolled in the study, divided into three groups: non-diabetic with morbid obesity (NDO; n=11 individuals), diabetic with mild obesity (T2D; n=12 individuals), and healthy controls (C; n=7 individuals). The mean CRP levels were significantly higher in the NDO group (6.6±4.7 mg/dL) than in the T2D (3.3±2.2 mg/dL) and C groups (2.5±3.2 mg/dL) (P=0.038). The GLP-1 levels following standard meal tolerance test and the area under the curve of GLP-1 did not differ among the three groups. The GLP-2 levels were significantly lower in the NDO and T2D than in the C group following standard meal tolerance test at all the times evaluated. The area under the curve of the GLP-2 was significantly lower in the NDO and T2D groups than in the C group (P=0.05 and P=0.01, respectively). CONCLUSION: GLP-2 levels were impaired in the individuals with obesity and diabetes. This mechanism seems to be enrolled in preventing the worsening of the glucose homeostasis in these individuals.

Glucagon-like peptide-2: A potential role in equine insulin dysregulation.

BACKGROUND: Equine insulin dysregulation (ID) is a common and poorly understood disorder that increases the risk of laminitis. Recent data show that the condition may be associated with alteration of the enteroinsular axis and enhanced glucose bioavailability. Upregulation of glucagon-like peptide-2 (GLP-2), an intestinotrophic peptide, leads to enhanced nutrient uptake and metabolic dysfunction in other species. OBJECTIVES: The study aimed to 1) determine whether GLP-2 is differentially expressed in insulin-dysregulated ponies, compared with healthy ponies, and 2) confirm intestinal expression of the GLP-2 receptor in horses (eGLP-2R). STUDY DESIGN: Cohort study. METHODS: Fasting and post-prandial GLP-2 concentrations were measured in archived plasma samples obtained from 25 mixed-breed ponies during two feeding studies. Measurements were undertaken with an ELISA that was validated for equine use as part of the current study. Ponies were designated as healthy or insulin-dysregulated based on an oral glucose test, and the results were compared between groups. The gene expression of the eGLP-2R was determined with polymerase chain reaction. RESULTS: Basal, fasted plasma GLP-2 concentrations were higher in ponies with ID, compared with healthy ponies. Grazing increased GLP-2 in healthy, but not in insulin-dysregulated, ponies. The eGLP-2R gene was expressed in the small intestine and pancreas. MAIN LIMITATIONS: The study was performed with a relatively small sample size. The specificity of the GLP-2 assay could not be determined due to the lack of equine-specific assay standards. CONCLUSIONS: This study has demonstrated that GLP-2 may be important in the pathogenesis of equine ID and suggests that the eGLP-2R may be a novel therapeutic target for the treatment of equine ID.

Comparação dos níveis de proteína C reativa, GLP-1 e GLP-2 entre indivíduos diabéticos, obesos mórbidos e controles saudáveis: um estudo exploratório / Comparison of the levels of c-reactive protein, glp-1 and glp-2 among individuals with diabetes, morbid obesity and healthy controls: an exploratory study

ABSTRACT BACKGROUND: The glucagon-like peptides 1 and 2 (GLP-1/GLP-2) are gut hormones that may directly affect the glucose homeostasis and their activity seems to be significantly affected by chronic inflammation. OBJECTIVE: To evaluate the postprandial levels of glucagon-like peptides 1 and 2 (GLP-1/GLP-2), C-reactive protein (CRP), and the postprandial glucose and insulin levels among individuals with obesity, type 2 diabetes, and healthy controls. METHODS: An exploratory cross-sectional study, which involved individuals awaiting for bariatric/metabolic surgery and healthy controls. Postprandial levels of GLP-1, GLP-2, glucose, and insulin were obtained after a standard meal tolerance test. Inflammation was assessed by means of CRP. RESULTS: There were 30 individuals enrolled in the study, divided into three groups: non-diabetic with morbid obesity (NDO; n=11 individuals), diabetic with mild obesity (T2D; n=12 individuals), and healthy controls (C; n=7 individuals). The mean CRP levels were significantly higher in the NDO group (6.6±4.7 mg/dL) than in the T2D (3.3±2.2 mg/dL) and C groups (2.5±3.2 mg/dL) (P=0.038). The GLP-1 levels following standard meal tolerance test and the area under the curve of GLP-1 did not differ among the three groups. The GLP-2 levels were significantly lower in the NDO and T2D than in the C group following standard meal tolerance test at all the times evaluated. The area under the curve of the GLP-2 was significantly lower in the NDO and T2D groups than in the C group (P=0.05 and P=0.01, respectively). CONCLUSION: GLP-2 levels were impaired in the individuals with obesity and diabetes. This mechanism seems to be enrolled in preventing the worsening of the glucose homeostasis in these individuals.

RESUMO CONTEXTO: Os peptídeos semelhantes ao glucagon 1 e 2 (GLP-1/GLP-2) são hormônios gastrointestinais que podem afetar diretamente a homeostase glicêmica; a atividade de ambos parece ser significativamente afetada pela inflamação crônica. OBJETIVO: Avaliar os níveis pós-prandiais dos peptídeos semelhantes ao glucagon 1 e 2 (GLP-1/GLP-2), proteína C reativa (PCR) e as curvas pós-prandiais de glucose e insulina entre indivíduos com obesidade, diabetes tipo 2 e controles saudáveis. MÉTODOS: Estudo piloto transversal, que envolveu indivíduos aguardando a realização de cirurgia bariátrica/metabólica e controles saudáveis. Os níveis de GLP-1, GLP-2, glucose e insulina foram obtidos após um teste de refeição padrão. A inflamação foi avaliada através dos níveis de PCR. RESULTADOS: Houve 30 indivíduos avaliados no estudo, divididos em três grupos: obesos mórbidos sem diabetes (NDO; n=11 pacientes), diabéticos com obesidade leve (T2D; n=12 pacientes) e controles (C; n=7 pacientes). Os níveis médios de PCR foram significativamente maiores no grupo NDO (6,6±4,7 mg/dL) do que nos grupos T2D (3,3±2,2 mg/dL) e C (2,5±3,2 mg/ dL) (P=0,038). Os níveis de GLP-1 após o teste de refeição padrão e a área sob a curva do GLP-1 não diferiram significativamente entre os grupos. Os níveis de GLP-2 foram significativamente mais baixos nos grupos NDO e T2D do que no grupo C em todos os tempos avaliados. A área sob a curva do GLP-2 foi significativamente menor nos grupos NDO e T2D do que no grupo C (P=0,05 and P=0,01, respectivamente). CONCLUSÃO: Os níveis de GLP-2 encontram-se alterados em indivíduos com obesidade e diabetes. Este mecanismo parece estar envolvido na prevenção da piora da homeostase glicêmica nestes indivíduos.

Promising Biomarkers of Environmental Enteric Dysfunction: A Prospective Cohort study in Pakistani Children.

Environmental Enteric Dysfunction (EED), a syndrome characterized by chronic gut inflammation, contributes towards stunting and poor response to enteric vaccines in children in developing countries. In this study, we evaluated major putative biomarkers of EED using growth faltering as its clinical proxy. Newborns (n = 380) were enrolled and followed till 18 months with monthly anthropometry. Biomarkers associated with gut and systemic inflammation were assessed at 6 and 9 months. Linear mixed effects model was used to determine the associations of these biomarkers with growth faltering between birth and 18 months. Fecal myeloperoxidase (neutrophil activation marker) at 6 months [ß = -0.207, p = 0.005], and serum GLP 2 (enterocyte proliferation marker) at 6 and 9 months [6M: ß = -0.271, p = 0.035; 9M: ß = -0.267, p = 0.045] were associated with decreasing LAZ score. Ferritin at 6 and 9 months was associated with decreasing LAZ score [6M: ß = -0.882, p < 0.0001; 9M: ß = -0.714, p < 0.0001] and so was CRP [ß = -0.451, p = 0.039] and AGP [ß = -0.443, p = 0.012] at 9 months. Both gut specific and systemic biomarkers correlated negatively with IGF-1, but only weakly correlated, if at all with each other. We therefore conclude that EED may be contributing directly towards growth faltering, and this pathway is not entirely through the pathway of systemic inflammation.

Glucagon-Like Peptides 1 and 2 Are Involved in Satiety Modulation After Modified Biliopancreatic Diversion: Results of a Pilot Study.

BACKGROUND: This paper aimed to evaluate the influence of modified biliopancreatic diversion (BPD) on the levels of GLP-1 and GLP-2 and correlate them with satiety regulation. METHODS: This is a pilot prospective cohort study that evaluated six mildly obese individuals with type 2 diabetes mellitus, which underwent modified BPD and were followed-up for 12 months. Levels of GLP-1 and GLP-2 after a standard meal tolerance test were determined and correlated with satiety scores obtained by means of a visual analogue scale (VAS). RESULTS: There were significant changes in BMI (33 ± 2.2 versus 26.3 ± 2.2 kg/m2; p < 0.001), HbA1c (7.9 ± 1.6 versus 5.8 ± 1.2%; p = 0.026), total cholesterol (172.3 ± 11.1 versus 134.7 ± 16.1 mg/dL; p < 0.001), LDL-c (103.3 ± 13 versus 64.6 ± 12.2 mg/dL; p < 0.001), and postprandial GLP-2 (972.7 ± 326.2 versus 1993.2 ± 1024.7; p = 0. 044). None of the scores obtained in the VAS significantly changed after surgery. After surgery, there were significant correlations of VAS scores and GLP-1 levels in question 01 ("how hungry do you feel?"; R = -0.928; p = .008) and GLP-2 levels in questions 02 ("how full do you feel?" R = 0.943; p = 0.005) and 04 ("how much do you think you can eat now? R = -0.829; p = 0.042). CONCLUSIONS: Modified BPD does not lead to significant changes in satiety evaluated by the VAS; different aspects of satiety regulation are correlated with the postprandial levels of GLP-1 (hunger feeling) and GLP-2 (satiation feeling and desire to eat) 1 year after modified BPD, signaling a specific postoperative gut hormone-related modulation of appetite.

Plasma concentrations of glucagon-like peptide 1 and 2 in calves fed calf starters containing lactose.

The objective of this study was to evaluate the effects of lactose inclusion in calf starters on plasma glucagon-like peptide (GLP)-1 and GLP-2 concentrations and gastrointestinal tract development in calves. Holstein bull calves (n = 45) were raised on an intensified nursing program using milk replacer containing 28.0% CP and 15.0% fat, and were fed a texturized calf starter containing 0 (control), 5.0 (LAC5), or 10.0% (LAC10; n = 15 for each treatment) lactose on a DM basis. Lactose was included in the starter by partially replacing dry ground corn in pelleted portion of the starter. All calf starters were formulated with 23.1% CP. The ethanol-soluble carbohydrate concentrations of the control, LAC5, and LAC10 starters were 7.3, 12.3, and 16.8% on a DM basis, respectively. Starch concentrations of the control, LAC5, and LAC10 starters were 29.7, 27.0, and 21.4% on a DM basis, respectively. All calves were fed treatment calf starters ad libitum. Blood samples were obtained weekly from 1 to 11 wk of age, and used to measure plasma GLP-1, GLP-2, and insulin concentrations, serum ß-hydroxybutyrate (BHB) concentration, and blood glucose concentration. At 80 d of age, calves were euthanized, and weights of the reticulorumen, omasum, abomasum, small intestine, and large intestine tissue were measured. Serum BHB concentration was higher for calves fed the LAC10 (171 µmol/L) starter than for those fed the control (151 µmol/L) and LAC5 (145 µmol/L) starters. Plasma GLP-1 and GLP-2 concentrations did not differ between treatments. However, relative to the baseline (1 wk of age), the plasma GLP-1 concentration was higher for the LAC10 (125.9%) than for the LAC5 (68.2%) and control (36.8%), and for the LAC5 than for the control (36.8%). Moreover, similar differences between treatments were observed for GLP-2 concentration relative to the baseline (88.2, 76.9, and 74.9% for LAC10, LAC5, and control treatments, respectively). The serum BHB concentration was positively correlated with the plasma GLP-1 concentration (r = 0.428). Furthermore, the plasma GLP-1 concentration was positively correlated with the insulin concentration (r = 0.793). The weights of the reticulorumen, omasum, abomasum, small intestine, and large intestine were not affected by the treatments. In conclusion, inclusion of lactose in calf starters resulted in higher plasma GLP-1 and GLP-2 concentrations, and BHB might be associated with higher plasma GLP-1 concentration.

Response of plasma glucagon-like peptide-2 to feeding pattern and intraruminal administration of volatile fatty acids in sheep.

Glucagon-like peptide-2 (GLP-2), a gut peptide secreted by enteroendocrine L cells, has recently been identified as a key regulator of intestinal growth and absorptive function in ruminants. However, reports on GLP-2 secretion are few, and more information regarding its secretion dynamics is needed. In this study, two experiments were conducted to elucidate the daily rhythm of GLP-2 secretion in response to feeding regimen and to investigate the effect of volatile fatty acids (VFA) on GLP-2 release in sheep. In experiment 1, blood samples were collected over 3 d from 4 Suffolk mature wethers adapted to a maintenance diet fed once daily; day 1 sampling was preceded by 24 h of fasting to reach steady state. On days 1 and 3, samples were collected every 10 min from 11:00 to 14:00 on both days and then every 1 h until 00:00 on day 1 only; feed was offered at 12:00. On day 2, feed was withheld, and sampling was performed every hour from 01:00 to 00:00. In experiment 2, 5 Suffolk mature wethers were assigned to 5 treatment groups of intraruminal administration of saline, acetate, propionate, butyrate, or VFA mix (acetate, propionate, and butyrate in a ratio of 65:20:15) in a 5 × 5 Latin square design. Blood samples were collected at 0, 1.5, 3, 6, 9, 12, 15, 20, 25, 30, 40, 50, 60, 90, and 120 min relative to the beginning of administration at 12:00. In both experiments, plasma GLP-2, glucagon-like peptide-1 (GLP-1), glucose, insulin, and ß-hydroxy butyric acid (BHBA) levels were measured. In experiment 1, incremental area under the curve was greater (P < 0.05) post-feeding than pre-feeding on days 1 and 3 for GLP-2 and tended to be greater (P < 0.1) on day 1 for GLP-1. Plasma insulin, glucose, and BHBA levels increased (P < 0.05) on day 1 post-feeding. Plasma GLP-2 was poorly correlated with GLP-1 but positively correlated with insulin, glucose, and BHBA. In experiment 2, administration of butyrate and VFA mix remarkably increased plasma GLP-2 (P = 0.05) and BHBA (P < 0.0001) levels compared with those in other treatments. Plasma GLP-1 levels were higher with butyrate administration compared with those in the saline, acetate, and VFA mix (P = 0.019). Propionate administration increased plasma glucose (P = 0.013) and insulin (P = 0.053) levels. Thus, our data confirmed that GLP-2 release is responsive to feeding and might be promoted by BHBA produced by the rumen epithelial metabolism of butyrate. Further molecular- and cellular-level studies are needed to determine the role of butyrate as a signaling molecule for GLP-2 release.

Berberine protects against diet-induced obesity through regulating metabolic endotoxemia and gut hormone levels.

Systemic inflammation, which can be induced by metabolic endotoxemia, and corresponding high­fat diet­mediated metabolic disorders are associated with gut microbiota. In the present study reverse transcription-polymerase chain reaction, immunofluorescence, pyrosequencing, ELISA and Oil Red O staining were performed to assess whether berberine can protect against diet-induced obesity, through modulating the gut microbiota and consequently improving metabolic endotoxemia and gastrointestinal hormone levels. Alterations in the gut microbiota induced by berberine resulted in a significant reduction in bacterial lipopolysaccharide levels in portal plasma. Levels of inflammatory and oxidative stress markers, as well as the mRNA expression levels of macrophage infiltration markers in visceral adipose tissue, were also reduced by berberine. Inhibition of the inflammatory response was associated with a reduction in intestinal permeability and an increase in the expression of tight junction proteins. In addition, berberine was reported to restore aberrant levels of gut hormones in the portal plasma, such as glucagon­like peptide­1 and ­2, peptide YY, glucose­dependent insulinotropic polypeptide and pancreatic polypeptide. The present findings indicated that berberine, through modulating gut microbiota, restored the gut barrier, reduced metabolic endotoxemia and systemic inflammation, and improved gut peptide levels in high­fat diet­fed rats. The present study suggests that berberine may be an effective therapeutic strategy for the treatment of obesity and insulin resistance.