Using a Complex Carbohydrate Mixture to Steer Fermentation and Improve Metabolism in Adults With Overweight and Prediabetes (DISTAL)

Inclusion Criteria: * Age 30-75 years * Male/female * BMI 28-40 kg/m2 * Impaired fasting glucose or glucose tolerance, determined using the following criteria (participant should meet at least one criteria): * HbA1c 42-47 mmol/mol OR fasting glucose (\>10h fasted) 5.6-6.9 mmol/l OR Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) \>1.85 Exclusion Criteria: * Diabetes mellitus (type 1 or 2) * Cardiovascular disease (except hypertension (\<160/100mmHg is allowed), pulmonary disease, kidney disease/failure, liver disease/failure * Gastrointestinal disease or a history of abdominal surgery (except appendectomy and cholecystectomy) * Diseases affecting glucose and/or lipid metabolism * Malignancy (except non-invasive skin cancer) * Auto-immune disease * Major mental disorders * Ongoing (infectious) disease or any disease with a life expectancy ≤5 years * Substance abuse (nicotine abuse (including e-cigarettes) defined as \>20 cigarettes per day; alcohol abuse defined as ≥8 drinks/week for females and ≥15 drinks/week for males(38); any drugs) * A change in weight ≥3kg over the last 3 months or plans to lose weight or follow a hypocaloric diet during the study period * Pre/pro/antibiotic use in the last 3 months or during the study * Use of medication that influences glucose or fat metabolism and inflammation, such as: * Use of statins (stable use ≥3 months prior to and during study is allowed) * Use of antidepressants (stable use ≥3 months prior to and during study is allowed) * Use of specific anticoagulants * Use of medication known to interfere with study outcomes * Use of β-blockers * Chronic corticosteroid treatment (\>7 consecutive days) * Regular use of laxatives 3 months prior to the study or during study period * Change in physical activity or diet during study period * Intensive physical activity (\>3h per week) * Pregnancy * Following a vegan or vegetarian diet; presence of food allergies, intolerances or diet restrictions interfering with the study.