Metabolic Effects of Short-Chain Fatty Acids in Healthy Individuals

The study will be conducted as a block-randomized cross-over study in healty participants (n=10). The participants will undergo two experimental days of three hours separated by a two to four weeks wash-out period. At the test days, participants will consume 3 grams of either propionate or butyrate in the form of sodium-propionate or sodium-butyrate together with 250 ml of water. The order of ingestion is determined by randomization.

The day prior to the experimental days, participants will consume a standardized control dinner and evening snack and abstain from alcohol and vigorous physical activity to ensure similar conditions on the experimental days. The standardized meal will be provided to the participants. On the test days, participants will be instructed to arrive by passive transport in an overnight fasted state (10 hours). Upon arrival, a DXA scan will be performed, after which a catheter will be inserted into an antecubital vein. Following 30 minutes of supine rest, baseline measurements will be performed, including indirect calorimetry, blood pressure measurement, flow-mediated vasodilation (FMD), and a fasting venous blood sample. Participants will then ingest 3 grams of propionate or butyrate within 5 minutes, together with 250 ml of water. After ingestion, participants will remain resting in bed for 3 hours, during which blood samples (15 ml each) will be collected continuously throughout the test day. Indirect calorimetry, blood pressure measurements, and FMD will be repeated at various time points post-ingestion. The test day will end with an ad libitum meal. The entire procedure will be repeated on the second test day.

• Glucose [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-30 min and 0 min) and post intake (10 min, 15 min, 22.5 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 180 min).]
• Fatty acids [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-30 min and 0 min) and post intake (10 min, 15 min, 22.5 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 180 min).]
• Flow mediated dilation measurement [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (min -15) and post intake (min 90).]
• Resting metabolic rate [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (min -15) and post intake (30 min, 60 min, 120 min)]
• Respiratory exchange ratio [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (min -15) and post intake (30 min, 60 min, 120 min)]
• Fatty Acid Composition [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-30 min and 0 min) and post intake (10 min, 15 min, 22.5 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 180 min).]
• Metabolites [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-30 min and 0 min) and post intake (10 min, 15 min, 22.5 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 180 min).]
• Hepatokines [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-30 min and 0 min) and post intake (10 min, 15 min, 22.5 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 180 min).]
• HOMA-Index [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-30 min and 0 min) and post intake (10 min, 15 min, 22.5 min, 30 min, 45 min, 60 min, 90 min, 120 min, and 180 min).]
• Satiety [Срок оценки: On day 1 (test day 1) and day 2 (test day 2) at baseline (-15 min) and post intake (30 min, 60 min, 90 min and 120 min).]