GLP-1 Concentrations Research Articles

Oat polar lipids and sunflower lecithin similarly improve cardiometabolic risk markers and appetite controlling hormone responses after breakfast and a subsequent lunch. A randomized crossover study in healthy adults

IntroductionThe alarming global increase in lifestyle-related disorders such as obesity and type 2 diabetes mellitus (T2DM) has increased during the last several decades. Poor dietary choices significantly contribute to this increase and prevention measures are urgently needed. Dietary intake of bioactive compounds found in foods are linked to a decrease likelihood of these disorders. For this purpose, a randomized crossover meal study was performed to compare the postprandial metabolic effects of lecithin and oat polar lipids in healthy subjects.Materials and methodsEighteen young healthy subjects ingested test meals enriched with lecithin, oat polar lipids (PLs) or rapeseed oil. There were four test meals (i) 15 g oat polar lipids: OPL, (ii) 18 g sunflower lecithin (of which 15 g were polar lipids): LPL, (iii) 18 g rapeseed oil: RSO, and (iv) reference white wheat bread: WWB. Lipid-enriched test meals contained equivalent amounts of total fat (18 g), and all breakfast meals contained 50 g available carbohydrates. The meals were served as breakfast followed by a standardised lunch (white wheat bread and meat balls) after 3.5 h. Test variables were measured at fasting and repeatedly during 5.5 h after ingestion of the breakfast.ResultsOur study demonstrated that both LPL and OPL had beneficial effects on postprandial glucose and insulin responses, and appetite regulating gut hormones, as compared to RSO and WWB. Significant increase in GLP-1, GIP, and PYY concentrations were seen after consuming breakfast meals with LPL and OPL, and ghrelin concentration was reduced compared to meals with RSO and WWB (p < 0.05). Furthermore, triglycerides (TG) concentration was significantly reduced after OPL compared to RSO (p < 0.05). Our data show that there were no significant variations in glycaemic and insulin responses, TG, and gut hormone concentrations between LPL and OPL during breakfast (0–210 min) or over the whole study period (0–330 min).ConclusionOur study revealed that the consumption of both lecithin and oat PLs included in breakfast meal may similarly enhance postprandial glucose tolerance, reduce TG, and enhance the secretion of incretins and appetite regulating hormones in healthy young adults.Clinical trial registrationClinicalTrials.gov, identifier NCT05139355.

Genetic Evidence for GLP-1 and GIP Receptors as Targets for Treatment and Prevention of MASLD/MASH.

Glucagon-like peptide-1 receptor (GLP1R) agonists and glucose-dependent insulinotropic polypeptide receptor (GIPR) agonists may help treat metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). However, their definitive effects are still unclear. Our study aims to clarify this uncertainty. We utilised conventional Mendelian randomisation (MR) analysis to explore potential causal links between plasma GLP-1/GIP concentrations and MASLD and its related traits. Next, we conducted drug-target MR analysis using highly expressed tissue data to assess the effects of corresponding drug perturbation on these traits. Finally, mediation analysis was performed to ascertain whether the potential causal effect is direct or mediated by other MASLD-related traits. Circulating 2-h GLP-1 and GIP concentrations measured during an oral glucose tolerance test showed hepatoprotective effects on MASLD risk (ORGLP-1 = 0.168 [95% CI 0.033-0.839], p = 0.030; ORGIP = 0.331 [95% CI 0.222-0.494], p = 6.31 × 10-8). GLP1R expression in the blood had a minimal causal effect on MASLD risk, whereas GIPR expression significantly affected MASLD risk (OR = 0.671 [95% CI 0.531-0.849], p = 9.07 × 10-4). Expression levels of GLP1R or GIPR in the blood significantly influenced MASLD-related clinical traits. Mediation analysis revealed that GIPR expression protected against MASLD, even after adjusting for type 2 diabetes or body mass index. GLP-1/GIP receptor agonists offer promise in lowering MASLD/MASH risk. GIP receptor agonists can exert direct and indirect effects on MASLD mediated by weight reduction or glycemic control improvement.

Efficacy of Lisosan G (fermented wheat) on reactive hypoglycemia after bariatric surgery.

post-bariatric hypoglycemia (PBH) is considered a chronic complication after gastric bypass (RYGB) impacting roughly 30% of patients. Current treatments often focus on nutritional interventions to reduce the frequency of episodes. This prospective study evaluated the effectiveness of Lisosan G (LG), a fermented wheat-based supplement added to the diet, in mitigating PBH episodes and elucidating its mechanism of action on the gut-pancreas axis. twenty subjects with PBH, who had undergone RYGB between 2015 and 2018, were enrolled. Subjects underwent clinical examination, blood test, and a 3-hour oral glucose load test (OGTT). Then, they were monitored for 2-weeks on a free diet with continuous glucose monitoring (CGM), which was extended for another 2-weeks after introduction of LG supplementation (5g, twice daily) on the same diet. Finally, subjects repeated OGTT and blood test. PBH was defined as interstitial glucose ≤54mg/dl. after treatment, a marked reduction in PBH time was observed (75[23-113] vs 16 [0-33], minutes, p<0.001). During OGTT, there was an increase in glucose nadir (44±11 vs 56±10, mg/dl, p=0.038), and a significantly decrease in total GLP-1 AUC (7.6±4.1 vs 6.5±3.8, nmol/L*min, p=0.043), in potentiation factor ratio (p=0.037) and in total insulin AUC (57±12 vs 49±9, nmol/L*min, p=0.043). LG effectively reduces PBH frequency and duration, probably by attenuating GLP-1 concentrations and leading to a decrease in the second phase of insulin secretion in response to glucose. These findings underscore the promise of LG as a novel adjunct therapy for PBH, particularly when added to the diet, and emphasize the need for further exploration into its microbiota-modulating and anti-inflammatory effects.

Revisiting the markers interleukin-6 and glucagon-like peptide-1 for targeting low-grade inflammation in type 2 diabetes: a meta-analysis and our lab experience.

Type 2 diabetes (T2DM) manifests as pancreatic disorder as a consequence of low-grade systemic inflammation, attributed to upregulated levels of interleukin-6 (IL-6). This in turn is associated with a reduced incretin effect with lower circulatory GLP-1 levels. Therefore, its important to monitor the circulating IL-6 and GLP-1 levels for better management and outcomes in T2DM patients. Limited studies being available in literature on circulating concentrations of GLP-1 and IL-6 in T2DM patients, a meta-analysis was conducted by identifying 1558 studies from 3 databases. As per inclusion and exclusion criteria, the studies were screened for the 2-markers.Forest plots were drawn for standardized mean differences and median values were deduced from the datasets. In parallel, analysis was conducted to ascertain the expression levels of the markers by ELISA (n = 52 T2DM patients) in real time. The meta-analysis showed a significant (p < 0.01) standardized mean difference of 3.82 and 1.04 for IL-6 and GLP-1 respectively. The median values obtained from analysis for IL-6 were 26.50 pg/ml which were higher than the controls downregulated levels of GLP-1(8.77 pg/ml) were noted. The above findings are corroborated by the results of our experimental analysis with IL-6 concentrations at 11.603pg/ml and GLP-1 at 13.05pg/ml. The study highlights that systemic concentrations of IL-6 and GLP-1 correspond to a persistent low-grade inflammation and decreased incretin effect in T2DM patients which manifest as pancreatic β-cell dysfunction. The expression of the markers is inversely correlated and monitoring their levels is clinically important for targeting them through their potential antagonists thus reducing the risk of complications, thereby improving the quality of life of the patients.

Clinical Consequences of Delayed Gastric Emptying With GLP-1 Receptor Agonists and Tirzepatide.

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are established therapeutics for type 2 diabetes and obesity. Among other mechanisms, they slow gastric emptying and motility of the small intestine. This helps limiting postprandial glycemic excursions and reducing chylomicron formation and triglyceride absorption. Conversely, motility effects may have detrimental consequences, e.g., retained gastric contents at endoscopy or general anesthesia, potentially complicated by pulmonary aspiration, or bowel obstruction. We searched the PubMed database for studies involving GLP-1RA therapy and adverse gastrointestinal/biliary events. Retained gastric contents at the time of upper gastrointestinal endoscopy are found more frequently with GLP-1 RAs, but rarely are associated with pulmonary aspiration. Well-justified recommendations for the peri-procedural management of GLP-1RAs (e.g., whether to withhold these medications, and for how long) are compromised by limited evidence. Important aspects to be considered are (a) their long half-lives, (b) the capacity of GLP-1 receptor agonism to slow gastric emptying even at physiological GLP-1 concentrations, (c) tachyphylaxis observed with prolonged treatment, and (d) the limited effect on gastric emptying in individuals with slow gastric emptying before initiating treatment. Little information is available on the influence of diabetes mellitus itself (i.e., in the absence of GLP-1 RA treatment) on retained gastric contents and pulmonary aspiration. Prolonged fasting periods regarding solid meal components, point-of-care ultrasound examination for retained gastric content, and the use of prokinetic medications like erythromycin may prove helpful, and are an important area needing further study to increase patient safety for those treated with GLP-1 RAs.

Reduced plasma interleukin-6 concentration after transcranial direct current stimulation to the prefrontal cortex

ObjectivesTranscranial direct stimulation (tDCS) targeted to the dorsolateral prefrontal cortex (DLPFC) reduces food intake and hunger, but its effects on circulating factors are unclear. We assessed the effect of repeated administration of tDCS to the left DLPFC (L-DLPFC) on concentrations of pro/anti-inflammatory and appetitive hormone concentrations. Materials and methodsTwenty-nine healthy adults with obesity (12 M; 42±11 y; BMI=39±8 kg/m2) received 3 consecutive inpatient sessions of either anodal or sham tDCS targeted to the L-DLPFC during a period of ad libitum food intake. Fasting plasma concentrations of IL-6, orexin, cortisol, TNF-α, IL-1β, ghrelin, PYY, and GLP-1 were measured before the initial and after the final tDCS sessions. ResultsIL-6 (β=-0.92 pg/ml p=0.03) decreased in the anodal group compared with sham, even after adjusting for kcal intake; there were no changes in other hormones. Mean kcal intake was associated with higher IL-1β and ghrelin concentrations after the ad libitum period (β=0.00018 pg/ml/kcal, p=0.03; β=0.00011 pg/ml/kcal, p=0.02; respectively), but not differ by intervention groups. ConclusionsIL-6 concentrations were reduced following anodal tDCS to the L-DLPFC independent of ad libitum intake. IL-6 concentrations reflect the inflammatory state of adiposity and may affect eating behavior and weight gain. These findings provide evidence of therapeutic benefit of tDCS.

The Severity of DSS-Induced Colitis Is Independent of the SCFA-FFAR2/3-GLP-1 Pathway Despite SCFAs Inducing GLP-1 Secretion via FFAR2/3.

Short-chain fatty acids (SCFAs) are the major microbial metabolites produced from the fermentation of dietary fiber in the gut. They are recognised as secretagogues of the glucagon-like peptides, GLP-1 and GLP-2, likely mediated by the activation of free fatty acid receptors 2 and 3 (FFAR2 and 3) expressed on enteroendocrine L-cells. Fiber-deficient diets are associated with decreased intestinal function and decreased colonic GLP-1 and GLP-2 content. Here, we speculated that the lowered colonic GLP-1 observed following a fiber-free diet was a consequence of decreased SCFA production and a subsequent decrease in FFAR2/3 activation. Furthermore, we explored the consequences of a fiber-free diet followed by intestinal injury, and we mechanistically explored the SCFA-FFAR2/3-GLP-1 pathway to explain the increased severity. Colonic luminal content from mice fed either a fiber-free or chow diet were analysed for SCFA content by LC-MS. FFAR2/3 receptor contributions to SCFA-mediated colonic GLP-1 secretion were assessed in isolated perfused preparations of the colon from FFAR2/3 double knockout (KO) and wild-type (WT) mice. Colitis was induced by the delivery of 3% dextran sulfate sodium (DSS) for 4 days in the drinking water of mice exposed to a fiber-free diet for 21 days. Colitis was induced by the delivery of 3% DSS for 7 days in FFAR2/3 KO mice. The removal of dietary fiber significantly decreased SCFA concentrations in the luminal contents of fiber-free fed mice compared to chow-fed mice. In the perfused colon, luminal SCFAs significantly increased colonic GLP-1 secretion in WT mice but not in FFAR2/3 KO mice. In the DSS-induced colitis model, the removal of dietary fiber increased the severity and prevented the recovery from intestinal injury. Additionally, colitis severity was similar in FFAR2/3 KO and WT mice after DSS application. In conclusion, the results confirm that the removal of dietary fiber is sufficient to decrease the colonic concentrations of SCFAs. Additionally, we show that a fiber-free diet predisposes the colon to increased intestinal injury, but this effect is independent of FFAR2 and FFAR3 signalling; therefore, it is unlikely that a fiber-free diet induces a decrease in luminal SCFAs and sensitivity to intestinal disease involves the SCFA-FFAR2/3-GLP-1 pathway.

Tauroursodeoxycholic Acid (TUDCA) Relieves Streptozotocin (STZ)-Induced Diabetic Rat Model via Modulation of Lipotoxicity, Oxidative Stress, Inflammation, and Apoptosis.

Tauroursodeoxycholic acid (TUDCA) is approved for the treatment of liver diseases. However, the antihyperglycemic effects/mechanisms of TUDCA are still less clear. The present study aimed to evaluate the antidiabetic action of TUDCA in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) in rats. Fifteen adult Wistar albino male rats were randomly divided into three groups (n = five in each): control, diabetic (STZ), and STZ+TUDCA. The results showed that TUDCA treatment significantly reduced blood glucose, HbA1c%, and HOMA-IR as well as elevated the insulin levels in diabetic rats. TUDCA therapy increased the incretin GLP-1 concentrations, decreased serum ceramide synthase (CS), improved the serum lipid profile, and restored the glycogen content in the liver and skeletal muscles. Furthermore, serum inflammatory parameters (such as TNF-α, IL-6, IL-1ß, and PGE-2) were substantially reduced with TUDCA treatment. In the pancreas, STZ+TUDCA-treated rats underwent an obvious enhancement of enzymatic (CAT and SOD) and non-enzymatic (GSH) antioxidant defense systems and a marked decrease in markers of the lipid peroxidation rate (MDA) and nitrosative stress (NO) compared to STZ-alone. At the molecular level, TUDCA decreased the pancreatic mRNA levels of iNOS and apoptotic-related factors (p53 and caspase-3). In conclusion, TUDCA may be useful for diabetes management and could be able to counteract diabetic disorders via anti-hyperlipidemic, antioxidant, anti-inflammatory, and anti-apoptotic actions.

745-P: Effects of Liraglutide on GLP-1, GIP, and Glucagon Concentrations in Persons with Type 2 Diabetes with Multiple Daily Insulin Injections during a 24-Week Period

745-P: Effects of Liraglutide on GLP-1, GIP, and Glucagon Concentrations in Persons with Type 2 Diabetes with Multiple Daily Insulin Injections during a 24-Week Period

Postprandial glycemic response to a high-protein diabetes-specific nutritional shake compared to isocaloric instant oatmeal in people with type 2 diabetes: a randomized, controlled, crossover trial.

Minimizing postprandial glucose response is an important goal for overall diabetes management. Diabetes-specific nutritional shakes (DSNS) have been clinically shown to minimize postprandial glucose response in people with type 2 diabetes (T2DM) compared to high-glycemic foods. However, it is unknown how a high-protein, low-fat DSNS impacts the GLP-1 response. We tested the postprandial glucose, insulin, and GLP-1 response to a high-protein, low-fat diabetes-specific nutritional shake (DSNS-HP) compared to isocaloric instant oatmeal (IOM) in a randomized, controlled, crossover study in adults with T2DM (n = 24). Participants were randomly selected to receive IOM or DSNS-HP on two test days. Glucose, insulin, and total GLP-1 concentration were measured at baseline and 15, 30, 45, 60, 90, 120, 180, and 240 min postprandially. Compared to IOM, the glucose-positive area under the curve (pAUC) was significantly lower (P = .021). DSNS-HP significantly increased GLP-1 pAUC response by 213% (P <.001) with a corresponding increase in insulin pAUC (P = .033) compared to IOM. A high-protein, low-fat DSNS leads to favorable changes in GLP-1 response and is a suitable option to minimize blood glucose response in people with type 2 diabetes.

Beta-glucan intake with energy and carbohydrate restricted meals: impact on subjective appetite and gastrointestinal appetite hormones in overweight adults

Energy restriction is commonly used as body weight-loss interventions (1). However, it modifies secretion of gastrointestinal appetite hormones, which might be expected to upregulate appetite and thus impair the ability to comply with prescribed intervention(1). Supplementation with soluble fibre may potentially counteract this matter (2). This study aimed to investigate whether addition of β- glucan to energy and carbohydrate-restricted meals impacts postprandial responses of gastrointestinal appetite hormones and subjective appetite in overweight adults.Twenty-three sedentary individuals living with overweight or obesity (age: 36 ± 8.5 years, BMI: 31.12 ± 4.04 kg/m2) participated in a double-blind randomised crossover study with two experimental arms, each lasting over two days. On day 1, participants consumed Counterweight PRO800 meal replacement shakes/soups for breakfast and dinner at home, each providing ~200 kcal and a carbohydrate-restricted lunch providing 35% of their habitual energy intake. On day 2, participants attended the metabolic investigation room where they consumed the same breakfast and lunch as on day 1. On both days, each meal was taken with either 3g β-glucan (Oat Well) or cellulose (Comprecel) as placebo. On Day 2, fasting and postprandial appetite scores were recorded, and fasting and postprandial blood samples were obtained for the measurements of plasma concentration of acylated ghrelin, PYY, and GLP-1. The study is registered at www.clinicaltrials.gov as NCT05981404.Two-way ANOVA showed that the postprandial concentrations of acylated ghrelin (β-glucan arm, 383 ± 23 pg/ml; placebo arm, 428 ± 23 pg/ml, P=0.02, treatment effect) and composite appetite scores (P=0.003, treatment effect) were significantly lower and PYY concentrations (β-glucan arm, 132 ± 5 pg/ml; Placebo arm, 110 ± 4 pg/ml, P= 0.003, treatment effect) significantly higher in the β- glucan arm than in the Placebo arm. The concentrations of GLP-1 were not different between arms (β-glucan arm, 29 ± 1 pM; placebo arm, 28 ± 0.9 pM, P=0.36, treatment effect).The obtained data suggests that consuming β -glucan with energy and carbohydrate-restricted meals can be expected to attenuate reduction in satiety and diminish increase in hunger. Therefore, supplementation with β-glucan during energy restriction intervention applied to body weight loss might lead to improve compliance and reduce discomfort of negative energy balance.

Examining the Direct and Indirect Effects of Postprandial Amino Acid Responses on Markers of Satiety following the Acute Consumption of Lean Beef-Rich Meals in Healthy Women with Overweight.

The consumption of protein-rich foods stimulates satiety more than other macronutrient-rich foods; however, the underlying mechanisms-of-action are not well-characterized. The objective of this study was to identify the direct and indirect effects of postprandial amino acid (AA) responses on satiety. Seventeen women (mean ± SEM, age: 33 ± 1 year; BMI: 27.8 ± 0.1 kg/m2) consumed a eucaloric, plant-based diet containing two servings of lean beef/day (i.e., 7.5 oz (207 g)) for 7 days. During day 6, the participants completed a 12 h controlled-feeding, clinical testing day including repeated satiety questionnaires and blood sampling to assess pre- and postprandial plasma AAs, PYY, and GLP-1. Regression and mediation analyses were completed to assess AA predictors and hormonal mediators. Total plasma AAs explained 41.1% of the variance in perceived daily fullness (p < 0.001), 61.0% in PYY (p < 0.001), and 66.1% in GLP-1 (p < 0.001) concentrations, respectively. Several individual AAs significantly predicted fluctuations in daily fullness, PYY, and GLP-1. In completing mediation analyses, the effect of plasma leucine on daily fullness was fully mediated by circulating PYY concentrations (indirect effect = B: 0.09 [Boot 95% CI: 0.032, 0.17]) as no leucine-fullness direct effect was observed. No other mediators were identified. Although a number of circulating AAs predict satiety, leucine was found to do so through changes in PYY concentrations in middle-aged women.

Augmented gut hormone response to feeding in older adults exhibiting low appetite.

Age-related changes in gut hormones may play a role in anorexia of ageing. The aim of this study was to determine concentrations of ghrelin, PYY, and GLP-1 in older adults exhibiting an anorexia of ageing phenotype. Thirteen older adults with healthy appetite (OA-HA; 8f, 75 ± 7 years, 26.0 ± 3.2 kg m−2), fifteen older adults with low appetite (OA-LA; 10f, 72 ± 7 years, 23.6 ± 3.1 kg m−2), and twelve young adults (YA; 6f, 22 ± 2 years, 24.4 ± 2.0 kg m−2) completed the study. Healthy appetite and low appetite were determined based on BMI, habitual energy intake, self-reported appetite, and laboratory-assessed ad libitum lunch intake. Participants provided a fasted measure of subjective appetite and blood sample (0 min) before consuming a standardised breakfast (450 kcal). Appetite was measured and blood samples were drawn throughout a 240-min rest period. At 240 min, an ad libitum lunch meal was consumed. Relative intake at lunch (expressed as percentage of estimated total energy requirement) was lower for OA-LA (19.8 ± 7.7%) than YA (41.5 ± 9.2%, p < 0.001) and OA-HA (37.3 ± 10.0%, p < 0.001). Ghrelin suppression was greater for OA-LA (net AUC, −78719 ± 74788 pg mL−1·240min−1) than both YA (−23899 ± 27733 pg mL−1·240min−1, p = 0.016) and OA-HA (−21144 ± 31161 pg mL−1·240min−1, p = 0.009). There were trends for higher GLP-1 concentrations in OA-LA compared with YA at 90 min (8.85 ± 10.4 pM vs. 1.88 ± 4.63 pM, p = 0.073) and 180 min (5.00 ± 4.71 pM vs. 1.07 ± 2.83 pM, p = 0.065). There was a trend for a greater PYY response for OA-LA compared with OA-HA (net AUC p = 0.062). “Anorexigenic response score” – a composite score of gut hormone responses to feeding – showed greater anorexigenic response in OA-LA, compared with YA and OA-HA. No differences were seen in subjective appetite. These observations suggest augmented anorexigenic responses of gut hormones to feeding may be causal mechanisms of anorexia of ageing.

Integrated multiple-omics reveals the regulatory mechanism underlying the effects of homologous Bacillus tequilensis (GCB-3) on growth performance of grass carp (Ctenopharyngodon idellus)

The purpose of this study was to investigate the regulatory mechanism of Bacillus tequilensis (GCB-3) in improving the growth performance of grass carp by microbiome and targeted metabolomics analysis. Fish were fed with different amounts of GCB-3 including B0 (0 CFU/g), B6 (1×106 CFU/g), B7 (1×107 CFU/g), B8 (1×108 CFU/g), and B9 (1×109 CFU/g) for 8 weeks. The results indicate that with the increase of dietary GCB-3 concentration, grass carp showed a significant linear trend in growth performance, and appetite factors showed a significant linear and quadratic trend, the growth performance and appetite-promoting factors in the B8 group reach their maximum value in the B8 group. Microbiome analysis found that Proteobacteria and Actinobacteria were the most abundant phylum in the gut microbiota of grass carp. The functional potential predicted that GCB-3 affected the synthesis and degradation of carbohydrates, amino acids, fatty acids and lipids. It found that GCB-3 also affected the tricarboxylic acid (TCA) cycle VII (acetate-producers) pathway. The results of targeted metabolomics showed a significant linear and quadratic increase in intestinal acetate with GCB-3 concentration and a maximum in the B8 group. The results of the correlation analysis showed a significant positive correlation between Actinobacteria abundance and acetic acid content, and also between TCA cycle VII (acetate-producers) pathway abundance and Actinobacteria abundance and acetic acid content. In B8 group, grass carp showed a faster regulation speed of blood glucose levels after glucose injection, and the GLP-1 content remained stable. The activities of glycolytic enzymes, lipolytic enzymes, protein metabolism enzymes, and their related mRNA expression levels in grass carp showed a linear or quadratic increasing trend. However, the expression levels of gluconeogenic enzymes and fatty acid synthesis enzyme related mRNA showed an opposite trend. In summary, the addition of 1×108 CFU/g GCB-3 in grass carp feed can improve the abundance of dominant bacterial phyla in the intestine, especially Actinobacteria, increase the concentration of intestinal acetate, provide substrate for the TCA cycle VII (acetate-producers) pathway, thereby regulating the nutrient metabolism of grass carp and ultimately promoting growth.

Glucose-regulatory hormones and growth in very preterm infants fed fortified human milk

BackgroundBovine colostrum (BC) contains a range of milk bioactive components, and it is unknown how human milk fortification with BC affects glucose-regulatory hormones in very preterm infants (VPIs). This study aimed to investigate the associations between hormone concentrations and fortification type, birth weight (appropriate/small for gestational age, AGA/SGA), milk intake, postnatal age, and body growth.Methods225 VPIs were randomized to fortification with BC or conventional fortifier (CF). Plasma hormones were measured before, one and two weeks after start of fortification. ΔZ-scores from birth to 35 weeks postmenstrual age were calculated.ResultsCompared with CF, infants fortified with BC had higher plasma GLP-1, GIP, glucagon, and leptin concentrations after start of fortification. Prior to fortification, leptin concentrations were negatively associated with growth, while IGF-1 concentrations associated positively with growth during fortification. In AGA infants, hormone concentrations generally increased after one week of fortification. Relative to AGA infants, SGA infants showed reduced IGF-1 and leptin concentrations.ConclusionFortification with BC increased the plasma concentrations of several glucose-regulatory hormones. Concentrations of IGF-1 were positively, and leptin negatively, associated with growth. Glucose-regulatory hormone levels were affected by birth weight, milk intake and postnatal age, but not closely associated with growth in VPIs.ImpactLittle is known about the variation in glucose-regulatory hormones in the early life of very preterm infants (VPIs).This study shows that the levels of glucose-regulatory hormones in plasma of VPIs are highly variable and modified by birth weight (appropriate or small for gestational age, AGA or SGA), the type of fortifier, enteral nutritional intake, and advancing postnatal age.The results confirm that IGF-1 levels are positively associated with early postnatal growth in VPIs, yet the levels of both IGF-1 and other glucose-regulatory hormones appeared to explain only a small part of the overall variation in growth rates.

Functional reorganization of memory processing in the hippocampus is associated with neuroprotector GLP-1 levels in type 2 diabetes

Type 2 diabetes (T2D) often impairs memory functions, suggesting specific vulnerability of the hippocampus. In vivo neuroimaging studies relating encoding and retrieval of memory information with endogenous neuroprotection are lacking. The neuroprotector glucagon-like peptide (GLP-1) has a high receptor density in anterior/ventral hippocampus, as shown by animal models. Using an innovative event-related fMRI design in 34 participants we investigated patterns of hippocampal activity in T2D (n = 17) without mild cognitive impairment (MCI) versus healthy controls (n = 17) during an episodic memory task. We directly measured neurovascular coupling by estimating the hemodynamic response function using event-related analysis related to encoding and retrieval of episodic information in the hippocampus. We applied a mixed-effects general linear model analysis and a two-factor ANOVA to test for group differences. Significant between-group differences were found for memory encoding, showing evidence for functional reorganization: T2D patients showed an augmented activation in the posterior hippocampus while anterior activation was reduced. The latter was negatively correlated with both GLP-1 pre- and post-breakfast levels, in the absence of grey matter changes. These results suggest that patients with T2D without MCI have pre-symptomatic functional reorganization in brain regions underlying episodic memory, as a function of the concentration of the neuroprotective neuropeptide GLP-1.

Differential effects of fish-oil and cocoa-butter based high-fat/high-sucrose diets on endocrine pancreas morphology and function in mice.

A high-fat/high-sucrose diet leads to adverse metabolic changes that affect insulin sensitivity, function, and secretion. The source of fat in the diet might inhibit or increase this adverse effect. Fish oil and cocoa butter are a significant part of our diets. Yet comparisons of these commonly used fat sources with high sucrose on pancreas morphology and function are not made. This study investigated the comparative effects of a fish oil-based high-fat/high-sucrose diet (Fish-HFDS) versus a cocoa butter-based high-fat/high-sucrose diet (Cocoa-HFDS) on endocrine pancreas morphology and function in mice. C57BL/6 male mice (n=12) were randomly assigned to dietary intervention either Fish-HFDS (n=6) or Cocoa-HFDS (n=6) for 22 weeks. Intraperitoneal glucose and insulin tolerance tests (IP-GTT and IP-ITT) were performed after 20-21 weeks of dietary intervention. Plasma concentrations of c-peptide, insulin, glucagon, GLP-1, and leptin were measured by Milliplex kit. Pancreatic tissues were collected for immunohistochemistry to measure islet number and composition. Tissues were multi-labelled with antibodies against insulin and glucagon, also including expression on Pdx1-positive cells. Fish-HFDS-fed mice showed significantly reduced food intake and body weight gain compared to Cocoa-HFDS-fed mice. Fish-HFDS group had lower fasting blood glucose concentration and area under the curve (AUC) for both GTT and ITT. Plasma c-peptide, insulin, glucagon, and GLP-1 concentrations were increased in the Fish-HFDS group. Interestingly, mice fed the Fish-HFDS diet displayed higher plasma leptin concentration. Histochemical analysis revealed a significant increase in endocrine pancreas β-cells and islet numbers in mice fed Fish-HFDS compared to the Cocoa-HFDS group. Taken together, these findings suggest that in a high-fat/high-sucrose dietary setting, the source of the fat, especially fish oil, can ameliorate the effect of sucrose on glucose homeostasis and endocrine pancreas morphology and function.

Extracellular electrophysiology on clonal human β-cell spheroids.

Pancreatic islets are important in nutrient homeostasis and improved cellular models of clonal origin may very useful especially in view of relatively scarce primary material. Close 3D contact and coupling between β-cells are a hallmark of physiological function improving signal/noise ratios. Extracellular electrophysiology using micro-electrode arrays (MEA) is technically far more accessible than single cell patch clamp, enables dynamic monitoring of electrical activity in 3D organoids and recorded multicellular slow potentials (SP) provide unbiased insight in cell-cell coupling. We have therefore asked whether 3D spheroids enhance clonal β-cell function such as electrical activity and hormone secretion using human EndoC-βH1, EndoC-βH5 and rodent INS-1 832/13 cells. Spheroids were formed either by hanging drop or proprietary devices. Extracellular electrophysiology was conducted using multi-electrode arrays with appropriate signal extraction and hormone secretion measured by ELISA. EndoC-βH1 spheroids exhibited increased signals in terms of SP frequency and especially amplitude as compared to monolayers and even single cell action potentials (AP) were quantifiable. Enhanced electrical signature in spheroids was accompanied by an increase in the glucose stimulated insulin secretion index. EndoC-βH5 monolayers and spheroids gave electrophysiological profiles similar to EndoC-βH1, except for a higher electrical activity at 3 mM glucose, and exhibited moreover a biphasic profile. Again, physiological concentrations of GLP-1 increased AP frequency. Spheroids also exhibited a higher secretion index. INS-1 cells did not form stable spheroids, but overexpression of connexin 36, required for cell-cell coupling, increased glucose responsiveness, dampened basal activity and consequently augmented the stimulation index. In conclusion, spheroid formation enhances physiological function of the human clonal β-cell lines and these models may provide surrogates for primary islets in extracellular electrophysiology.

Evaluation of the relationship between plasma glucagon-like peptide-2 and gastrointestinal dysbiosis in canine chronic enteropathies.

Chronic enteropathies are a common cause of morbidity in dogs and are associated with disruption of the normal gastrointestinal mucosal barrier. The objective of this prospective study was to determine the association between measures of gastrointestinal dysbiosis and plasma concentrations of glucagon-like peptide-2, a hormone responsible for normal mucosal structure, in dogs with chronic enteropathies. Fecal 16S V4 rRNA gene sequencing and quantitative PCR via the dysbiosis index was performed on 16 healthy controls and 18 dogs with chronic enteropathy prior to and 1 month after initiation of individualized therapy. Fasting and post-prandial plasma GLP-2 concentrations were measured via ELISA in healthy dogs and chronic enteropathy dogs at both time points. Alpha and beta diversity indices, as well as bacterial population abundances were compared between groups and time-points. Principal component analysis combined with least squares regression was used to identify taxa contributing to glucagon-like peptide-2 variance among groups. While the dysbiosis index did not differ between healthy dogs and dogs with chronic enteropathy, 16S V4 genomic sequencing identified 47 operational taxonomic units that differed between the groups, all but 2 of which resolved following chronic enteropathy treatment. Principal component analysis identified 6 families and 19 genera that contributed to differences in glucagon-like peptide-2 concentrations between groups. Dysbiosis associated with chronic enteropathies in dogs may contribute to the observed lower plasma glucagon-like peptide-2 concentrations. Further research into mechanisms of microbiota impact on the enteroendocrine system is needed. Association between glucagon-like peptide-2 secretion and microbiome indices may help to guide research into future treatment strategies for dogs with chronic enteropathy.

Effect of feeding sodium butyrate to beef female cows during pre- and post-partum period on concentrations of glucagon-like peptides in plasma and colostrum.

The objective of this study was to evaluate the effect of feeding beef cows with sodium butyrate during the late pregnancy and early post-partum periods on concentrations of glucagon-like peptide (GLP)-1 and 2 in plasma, colostrum, and transition milk. Twelve Japanese Black female cows were fed concentrate feed without (CON; n = 6) or with (BUTY; n = 6) sodium butyrate supplementation at 1.1% of dietary dry matter from -60 d relative to the expected parturition date to 4d after parturition. Plasma total cholesterol concentration was higher for the BUTY than for the CON (P = 0.04). In addition, plasma GLP-1 concentration was higher for the BUTY than for the CON at 3d after calving (P < 0.05). This study showed for the first time that GLP-1 is present in the colostrum of Japanese Black cows at higher concentrations as compared to in plasma (P < 0.01). On the other hand, no treatment effect was observed for concentrations of metabolite and hormone in colostrum and transition milk. In summary, feeding beef cows with sodium butyrate during the late gestation and early post-partum period likely increases plasma GLP-1 concentrations post-partum without affecting the components of colostrum and transition milk.