Clinical Research Directory

Impact of Training Load on the Gut miCrobiome And Its Relation to exeRcise Performance, mUscle Phenotype, and markerS of Overreaching in Healthy Men

The goal of this study is to learn how different amounts of supervised indoor cycling training change gut health (gut bacteria, the substances gut bacteria make, and the gut barrier integrity), and how these changes relate to changes in fitness, muscle health, and signs of doing too much training (a state called 'overreaching'). The study includes healthy, recreationally active men aged 18 to 45 years. The primary questions, for which the study is powered (sufficient participants included), are: 1. Does moderate load training change blood and faecal levels of butyrate (a short-chain fatty acid made by gut bacteria) after eight weeks compared with a control group? 2. Compared to moderate load training, do higher training loads lead to different responses in blood and faecal levels of butyrate? Researchers will compare: * A control group that does not complete structured training; * A moderate-load training group that completes eight weeks of supervised cycling (4x/week); * A high-load training group that completes four weeks of moderate-load training followed by four weeks of higher training load (twice the number of training sessions). Participants will: * Be randomly assigned to one of the three groups; * Complete 8 weeks of supervised indoor cycling sessions if assigned to a training group; * Complete four study assessment periods (baseline, after week four, after week eight, and after a short taper (rest period); * Provide blood, stool, skeletal muscle, urine, saliva, and breath samples during the assessment periods; * Complete fitness and performance tests and questionnaires during the assessment periods.

Glucose Tolerance Study

The goal of this clinical trial is to assess whether TRPTI (oleoylethanolamide) can improve glucose tolerance in healthy adults aged 18 years and above with BMI 18.5-29.9 kg/m². The main questions it aims to answer are: * Does TRPTI improve glucose tolerance as measured by glucose area under the curve (AUC) from 0-120 minutes following a glucose load? * Does TRPTI reduce peak glucose response and alter the time to peak glucose concentration? * Are there dose-dependent effects between 150 mg and 300 mg doses of TRPTI? Researchers will compare TRPTI 150 mg, TRPTI 300 mg, and placebo in a crossover design to see if TRPTI improves glucose metabolism and insulin sensitivity compared to placebo. Participants will complete 3 clinic visits (each lasting approximately 4 hours) with a minimum 6-day washout period between visits.

Evaluation of Sex Differences in Glucose Metabolism in Response to Sleep Curtailment

The goal of this study is to learn whether insufficient sleep affects glucose metabolism differently in healthy men and women.

The Impact of a 48-hour Fast with or Without Exercise on Immune Cell Metabolism and Glycemic Control in Healthy Active Adults

Many individuals engage in fasting for its purported health benefits but the effects of fasting on immune cell and whole body metabolism are not well understood in humans. Moreover, how exercising during a prolonged fast impacts immunometabolic outcomes is unclear. This study will determine how a 2 day fast - performed with or without daily exercise - impacts immune cell bioenergetics, immune cell function, and whole-body glycemic control in healthy active individuals.

Effect of Daily Erythritol Versus Sucrose Intake Over 5 Weeks on Glucose Tolerance in Adolescents

Childhood and adolescence are crucial periods for prevention of obesity, as obese children are five times more likely to be obese at adulthood than lean children. To this purpose, sugar consumption should be reduced. The sugar alcohol erythritol is increasingly popular as sugar substitute in the food industry and is also recommended to diabetic patients. The substance is freely available. Recent acute studies show that erythritol has a positive influence on satiation and gastric emptying without affecting insulin and plasma glucose. In this trial, the investigators aim to assess the effect of a chronic intake of erythritol versus sucrose on insulin resistance in healthy adolescents. EryClot-Pilot: Erythritol is also produced by the human body and possibly elevated erythritol levels in the blood are an indication of an increased risk of cardiovascular disease, obesity or diabetes in the future. In a recently published study, a possible effect of erythritol on blood clotting function was described. In this in vitro experiment, increased blood clotting was observed when erythritol was added to clotting cells (platelets) in the test tube. Studies in humans on blood coagulation after administration of erythritol are missing so far. With a pilot study, the investigators study whether erythritol is detectable in the blood after administration of glucose and fructose. Furthermore, the erythritol level in the blood and a possible effect on the blood coagulation function after administration of erythritol will be investigated. These preliminary tests serve to clarify the data situation so that further studies can be based on them. The preliminary results of the EryClot\_Pilot study indicate that there appears to be no measurable effect of erythritol on thrombocyte aggregation. This implicates that there is a discrepancy between our results and the results reported in a recent published study. This is why we need to assess the effects of erythritol administration on more parameters of blood coagulation as well as in more subjects. Due to a study published in June 2024, there appears the need to investigate the effects of xylitol on blood clotting function as well. EryClot in vitro: In addition to the human EryClot study, we will conduct in vitro experiments (aggregometry assay after addition of erythritol or xylitol in human platelet rich plasma).

Peripheral Heating and Glucose Tolerance

Effect of peripheral heating on glucose tolerance