Could collagen supplements tame blood sugar spikes?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Main Inclusion Criteria: * Prediabetic subjects: Male and female subjects with prediabetic HbA1c values between 5.7% and 6.4% and/or fasting glucose ≥ 100 mg/dL and ≤ 125 mg/dL (in venous plasma) (twice confirmed at two independent days if HbA1c is \< 5.7%) or Healthy normo-glycaemic subjects: fasting glucose \<100 mg/dL and HbA1c is \< 5.7% * Age: 18-70 years * Body mass index 19-35 kg/m2 * Current Non-smoker * Signed informed consent form * No changes in food habits or physical activity 3 months prior to screening and during the study * If applicable, stable intake of chronic medication of at least 4 weeks Main Exclusion Criteria: * Subjects with diagnosed Type 2 Diabetes mellitus with medical treatment * Presence of disease or drug(s) influencing digestion (incl. recent intake of antibiotics) and absorption of nutrients * Intake of medications known to affect glucose tolerance, e.g., diabetic medication, SGLT-2 inhibitors, GLP-1 receptor agonists, steroids, protease inhibitors or antipsychotics * Chronic intake of substances affecting blood coagulation (e.g. acetylic acid (100 mg as standard prophylactic treatment allowed when dose is stable 1 month prior to screening), anticoagulants, diuretics, thiazides (diuretics and thiazides allowed e.g. for hypertension treatment when dose is stable 1 month prior to screening)), which in the Investigator's opinion would impact patient safety * Severe liver or renal disease or laboratory evidence of hepatic dysfunction (i.e. alkaline phosphatase, ALT, AST \>3 x ULN) * Known inflammatory or malignant gastrointestinal diseases (i.e. colitis ulcerosa, Morbus Crohn, celiac disease, malignant diseases e.g. colon-cancer, rectum cancer, pancreatitis) * Clinically relevant findings as established by medical history, physical examination, clinical laboratory and/or vital signs * Intake of food supplements known to affect glucose tolerance, e.g., cinnamon capsules, conjugated linoleic acids * Drug-, alcohol- and medication abuses * Pregnant or breast-feeding women