Explore the vast range of titles available.

Aims/hypothesisLifestyle modification and weight loss are cornerstones of type 2 diabetes management. However, carbohydrate restriction may have weight-independent beneficial effects on glycaemic control. This has been difficult to demonstrate because low-carbohydrate diets readily decrease body weight. We hypothesised that carbohydrate restriction enhances the beneficial metabolic effects of weight loss in type 2 diabetes.MethodsThis open-label, parallel RCT included adults with type 2 diabetes, HbA1c 48–97 mmol/mol (6.5–11%), BMI >25 kg/m2, eGFR >30 ml min−1 [1.73 m]−2 and glucose-lowering therapy restricted to metformin or dipeptidyl peptidase-4 inhibitors. Participants were randomised by a third party and assigned to 6 weeks of energy restriction (all foods were provided) aiming at ~6% weight loss with either a carbohydrate-reduced high-protein diet (CRHP, percentage of total energy intake [E%]: CH30/P30/F40) or a conventional diabetes diet (CD, E%: CH50/P17/F33). Fasting blood samples, continuous glucose monitoring and magnetic resonance spectroscopy were used to assess glycaemic control, lipid metabolism and intrahepatic fat. Change in HbA1c was the primary outcome; changes in circulating and intrahepatic triacylglycerol were secondary outcomes. Data were collected at Copenhagen University Hospital (Bispebjerg and Herlev).ResultsSeventy-two adults (CD 36, CRHP 36, all white, 38 male sex) with type 2 diabetes (mean duration 8 years, mean HbA1c 57 mmol/mol [7.4%]) and mean BMI of 33 kg/m2 were enrolled, of which 67 (CD 33, CRHP 34) completed the study. Body weight decreased by 5.8 kg (5.9%) in both groups after 6 weeks. Compared with the CD diet, the CRHP diet further reduced HbA1c (mean [95% CI] −1.9 [−3.5, −0.3] mmol/mol [−0.18 (−0.32, −0.03)%], p = 0.018) and diurnal mean glucose (mean [95% CI] −0.8 [−1.2, −0.4] mmol/l, p < 0.001), stabilised glucose excursions by reducing glucose CV (mean [95% CI] −4.1 [−5.9, −2.2]%, p < 0.001), and augmented the reductions in fasting triacylglycerol concentration (by mean [95% CI] −18 [−29, −6]%, p < 0.01) and liver fat content (by mean [95% CI] −26 [−45, 0]%, p = 0.051). However, pancreatic fat content was decreased to a lesser extent by the CRHP than the CD diet (mean [95% CI] 33 [7, 65]%, p = 0.010). Fasting glucose, insulin, HOMA2-IR and cholesterol concentrations (total, LDL and HDL) were reduced significantly and similarly by both diets.Conclusions/interpretationModerate carbohydrate restriction for 6 weeks modestly improved glycaemic control, and decreased circulating and intrahepatic triacylglycerol levels beyond the effects of weight loss itself compared with a CD diet in individuals with type 2 diabetes. Concurrent differences in protein and fat intakes, and the quality of dietary macronutrients, may have contributed to these results and should be explored in future studies.Trial registrationClinicalTrials.gov NCT03814694.FundingThe study was funded by Arla Foods amba, The Danish Dairy Research Foundation, and Copenhagen University Hospital Bispebjerg Frederiksberg.

BackgroundRecently, we demonstrated that whey protein (WP) combined with low dietary fiber improved lipemia, a risk factor for cardiovascular disease in subjects with abdominal obesity. In the present study, we investigated the effects of intake of WP and dietary fiber from enzyme-treated wheat bran on other metabolic parameters of the metabolic syndrome.MethodsThe study was a 12-week, double-blind, randomized, controlled, parallel intervention study. We randomized 73 subjects with abdominal obesity to 1 of 4 iso-energetic dietary interventions: 60 g per day of either WP hydrolysate or maltodextrin (MD) combined with high-fiber (HiFi; 30 g dietary fiber/day) or low-fiber (LoFi; 10 g dietary fiber/day) cereal products. We assessed changes in insulin sensitivity, gut hormones (GLP-1, GLP-2, GIP, and peptide YY), body composition, 24-h BP, resting energy expenditure and respiratory exchange ratio (RER), and appetite.ResultsSixty-five subjects completed the trial. Subjective hunger ratings were lower after 12 weeks of WP compared with MD, independent of fiber content (P = 0.02). We found no effects on ratings of satiety, fullness or prospective food consumption for either of the interventions. Intake of WP combined with LoFi increased the postprandial peptide YY response. There were no effects of WP or fiber on insulin sensitivity, body composition, energy expenditure, incretins, or 24-h BP.ConclusionsWP consumption for 12 weeks reduced subjective ratings of hunger in subjects with abdominal obesity. Neither WP nor dietary fiber from wheat bran affected insulin sensitivity, 24-h BP, gut hormone responses, body composition, or energy expenditure compared with MD and low dietary fiber.

Abstract Background D-3-hydroxybutyrate (D-3-OHB) is a ketone body that serves as an alternative nutritional fuel but also as an important signaling metabolite. Oral ketone supplements containing D/L-3-OHB are becoming a popular approach to achieve ketosis. Aim To explore the gut-derived effects of ketone supplements. Methods Eight healthy lean male volunteers were investigated on 2 separate occasions: i) Following oral D/L-3-OHB consumption (oral) ii) Following isoketonemic intravenous ketone (D/L-3-OHB) infusion. An acetaminophen test was performed to evaluate gastric emptying and blood samples were obtained consecutively throughout the study period. Results We show that oral consumption of D/L-3-OHB stimulates cholecystokinin release (P = 0.02), elevates insulin (P = 0.03) and C-peptide (P < 0.001) concentrations, and slows gastric emptying (P = 0.01) compared with matched intravenous D/L-3-OHB administration. Measures of appetite and plasma concentrations of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were unaffected by interventions. Conclusion Our findings show that D/L-3-OHB exert incretin effects and indicate luminal sensing in the gut endothelium. This adds to our understanding of ketones as signaling metabolites and displays the important difference between physiological ketosis and oral ketone supplements.

ObjectivesGastrointestinal hormones contribute to the beneficial effects of Roux-en-Y gastric bypass surgery (RYGB) on glycemic control. Secretin is secreted from duodenal S cells in response to low luminal pH, but it is unknown whether its secretion is altered after RYGB and if secretin contributes to the postoperative improvement in glycemic control. We hypothesized that secretin secretion increases after RYGB as a result of the diversion of nutrients to more distal parts of the small intestine, and thereby affects islet hormone release.MethodsA specific secretin radioimmunoassay was developed, evaluated biochemically, and used to quantify plasma concentrations of secretin in 13 obese individuals before, 1 week after, and 3 months after RYGB. Distribution of secretin and its receptor was assessed by RNA sequencing, mass-spectrometry and in situ hybridization in human and rat tissues. Isolated, perfused rat intestine and pancreas were used to explore the molecular mechanism underlying glucose-induced secretin secretion and to study direct effects of secretin on glucagon, insulin, and somatostatin secretion. Secretin was administered alone or in combination with GLP-1 to non-sedated rats to evaluate effects on glucose regulation.ResultsPlasma postprandial secretin was more than doubled in humans after RYGB (P < 0.001). The distal small intestine harbored secretin expressing cells in both rats and humans. Glucose increased the secretion of secretin in a sodium-glucose cotransporter dependent manner when administered to the distal part but not into the proximal part of the rat small intestine. Secretin stimulated somatostatin secretion (fold change: 1.59, P < 0.05) from the perfused rat pancreas but affected neither insulin (P = 0.2) nor glucagon (P = 0.97) secretion. When administered to rats in vivo, insulin secretion was attenuated and glucagon secretion increased (P = 0.04), while blood glucose peak time was delayed (from 15 to 45 min) and gastric emptying time prolonged (P = 0.004).ConclusionsGlucose-sensing secretin cells located in the distal part of the small intestine may contribute to increased plasma concentrations observed after RYGB. The metabolic role of the distal S cells warrants further studies.

Aims/hypothesisThe aim was to investigate whether an intensive lifestyle intervention, with high volumes of exercise, improves beta cell function and to explore the role of low-grade inflammation and body weight.MethodsThis was a randomised, assessor-blinded, controlled trial. Ninety-eight individuals with type 2 diabetes (duration <10 years), BMI of 25–40 kg/m2, no use of insulin and taking fewer than three glucose-lowering medications were randomised (2:1) to either the standard care plus intensive lifestyle group or the standard care alone group. Standard care consisted of individual guidance on disease management, lifestyle advice and blinded regulation of medication following a pre-specified algorithm. The intensive lifestyle intervention consisted of aerobic exercise sessions that took place 5–6 times per week, combined with resistance exercise sessions 2–3 times per week, with a concomitant dietary intervention aiming for a BMI of 25 kg/m2. In this secondary analysis beta cell function was assessed from the 2 h OGTT-derived disposition index, which is defined as the product of the Matsuda and the insulinogenic indices.ResultsAt baseline, individuals were 54.8 years (SD 8.9), 47% women, type 2 diabetes duration 5 years (IQR 3–8) and HbA1c was 49.3 mmol/mol (SD 9.2); 6.7% (SD 0.8). The intensive lifestyle group showed 40% greater improvement in the disposition index compared with the standard care group (ratio of geometric mean change [RGM] 1.40 [95% CI 1.01, 1.94]) from baseline to 12 months’ follow-up. Plasma concentration of IL-1 receptor antagonist (IL-1ra) decreased 30% more in the intensive lifestyle group compared with the standard care group (RGM 0.70 [95% CI 0.58, 0.85]). Statistical single mediation analysis estimated that the intervention effect on the change in IL-1ra and the change in body weight explained to a similar extent (59%) the variance in the intervention effect on the disposition index.Conclusions/interpretationOur findings show that incorporating an intensive lifestyle intervention, with high volumes of exercise, in individuals with type 2 diabetes has the potential to improve beta cell function, associated with a decrease in low-grade inflammation and/or body weight.Trial registrationClinicalTrials.gov NCT02417012

Aims/hypothesis Exercise has a profound effect on insulin sensitivity in skeletal muscle. The euglycaemic–hyperinsulinaemic clamp (EHC) is the gold standard for assessment of insulin sensitivity but it does not reflect the hyperglycaemia that occurs after eating a meal. In previous EHC investigations, it has been shown that the interstitial glucose concentration in muscle is decreased to a larger extent in previously exercised muscle than in rested muscle. This suggests that previously exercised muscle may increase its glucose uptake more than rested muscle if glucose supply is increased by hyperglycaemia. Therefore, we hypothesised that the exercise-induced increase in muscle insulin sensitivity would appear greater after eating a meal than previously observed with the EHC. Methods Ten recreationally active men performed dynamic one-legged knee extensor exercise for 1 h. Following this, both femoral veins and one femoral artery were cannulated. Subsequently, 4 h after exercise, a solid meal followed by two liquid meals were ingested over 1 h and glucose uptake in the two legs was measured for 3 h. Muscle biopsies from both legs were obtained before the meal test and 90 min after the meal test was initiated. Data obtained in previous studies using the EHC ( n =106 participants from 13 EHC studies) were used for comparison with the meal-test data obtained in this study. Results Plasma glucose and insulin peaked 45 min after initiation of the meal test. Following the meal test, leg glucose uptake and glucose clearance increased twice as much in the exercised leg than in the rested leg; this difference is twice as big as that observed in previous investigations using EHCs. Glucose uptake in the rested leg plateaued after 15 min, alongside elevated muscle glucose 6-phosphate levels, suggestive of compromised muscle glucose metabolism. In contrast, glucose uptake in the exercised leg plateaued 45 min after initiation of the meal test and there were no signs of compromised glucose metabolism. Phosphorylation of the TBC1 domain family member 4 (TBC1D4; p-TBC1D4 Ser704 ) and glycogen synthase activity were greater in the exercised leg compared with the rested leg. Muscle interstitial glucose concentration increased with ingestion of meals, although it was 16% lower in the exercised leg than in the rested leg. Conclusions/interpretation Hyperglycaemia after meal ingestion results in larger differences in muscle glucose uptake between rested and exercised muscle than previously observed during EHCs. These findings indicate that the ability of exercise to increase insulin-stimulated muscle glucose uptake is even greater when evaluated with a meal test than has previously been shown with EHCs. Graphical Abstract

There is an urgent need for sustainable protein sources to meet rising global nutritional demands. Here, we show that a commercially scalable microbial lysate from Methylococcus capsulatus Bath (McB), used as a dietary protein, orchestrates host-diet-microbe interactions that protect against gastrointestinal inflammation. McB administration rapidly reshapes the gut microbiota and upregulates microbial fermentation pathways, while robustly increasing peripherally induced regulatory T cells (pTregs) across intestinal regions, independent of the microbiota. In contrast, McB-driven induction of tolerogenic Th17 cells requires a functional microbiota with intact fermentation capacity. In models of mucositis and colitis, McB preserves villus architecture, restores mucosal integrity, and reduces disease severity. Mechanistically, these effects depend on microbial fermentation and functional GLP-2 receptor signalling, yet are independent of endogenous GLP-2 secretion, indicating a fermentation-driven molecular mimicry of GLP-2R activation. Collectively, our findings position microbial lysates as a sustainable nutritional strategy that improves gastrointestinal health through defined immune and microbial pathways. Here, Yang-Jensen et al. demonstrate that a scalable microbial protein lysate from Methylococcus capsulatus Bath reshapes gut microbiota and T cells and, via fermentation-driven GLP-2 receptor mimicry, protects against gastrointestinal inflammation while providing sustainable protein nutrition

Post-bariatric hypoglycemia (PBH) can be a serious complication after Roux-en-Y gastric bypass (RYGB), and treatment with somatostatin analogs has been suggested. We investigated the acute effects of three different doses of pasireotide (75 μg, 150 μg, and 300 μg) on the postprandial glucose metabolism in five RYGB-operated individuals with PBH using a mixed meal test. All three doses prevented hypoglycemia but were associated with a notable increase in postprandial hyperglycemia. Moreover, all doses greatly diminished insulin, C-peptide, and glucagon-like peptide-1 responses. Considering its strong hyperglycemic potential, we suggest that pasireotide should be administered carefully in RYGB-operated individuals with PBH, and if necessary, a 75 μg dose seems sufficient to prevent hypoglycemia.

Aims/hypothesisType 1 diabetes is characterised by reduced glucagon response to hypoglycaemia, increasing the risk of insulin treatment-associated hypoglycaemia known to hamper glycaemic control. We previously reported a glucagonotropic effect of exogenous glucose-dependent insulinotropic polypeptide (GIP) during insulin-induced hypoglycaemia in individuals with type 1 diabetes. Here we investigate the effect of a 6-day s.c. GIP infusion on time in glycaemic range as assessed by continuous glucose monitoring (CGM) in individuals with type 1 diabetes.MethodsIn a randomised, placebo-controlled, double-blind crossover study, time in glycaemic range (assessed by double-blinded CGM) was evaluated in 20 men with type 1 diabetes (18–75 years, stable insulin treatment ≥3 months, diabetes duration 2–15 years, fasting plasma C-peptide below 200 pmol/l, BMI 20–27 kg/m2, HbA1c <69 mmol/mol [8.5%]) during two × 6 days of continuous s.c. GIP (6 pmol kg−1 min−1) and placebo (saline [154 mmol/l NaCl]) infusion, respectively, with an interposed 7-day washout period. The primary outcome was glycaemic time below range, time in range and time above range.ResultsThere were no significant differences in time below range (<3.9 mmol/l, p = 0.53) or above range (>10 mmol/l, p = 0.32) during night-time or daytime, in mean glucose, or in hypoglycaemic events as assessed by CGM. GIP altered neither self-reported hypoglycaemia nor safety measures. Compared with placebo, GIP significantly increased time in tight range (3.9–7.8 mmol/l) during daytime (06:00–23:59 hours) by [mean ± SEM] 11.2 ± 5.1% [95% CI 0.41, 21.9] (p = 0.02).Conclusions/interpretationSix-day s.c. GIP infusion in men with type 1 diabetes did not procure convincing effect on overall time in range, but increased time in tight glycaemic range during daytime by ~2 h per day.Trial registrationClinicalTrials.gov NCT03734718.FundingThe study was funded by grants from The Leona M. and Harry B. Helmsley Charitable Trust and Aase og Ejnar Danielsens Fond.

The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma concentrations of GLP-1 and GIP is often an important endpoint in both clinical and preclinical studies and, therefore, accurate measurement of these hormones is important. Here, we provide an overview of current approaches for the measurement of the incretin hormones, with particular focus on immunological methods.