– Functions:
– SCFAs are produced when dietary fiber is fermented in the colon.
– Macronutrient composition of diets affects circulating SCFAs.
– Acetate, propionate, and butyrate are the three most common SCFAs.
– SCFAs and medium-chain fatty acids are primarily absorbed through the portal vein during lipid digestion.
– Long-chain fatty acids are packed into chylomicrons, enter lymphatic capillaries, then transfer to the blood at the subclavian vein.
– Importance:
– SCFAs have diverse physiological roles in body functions.
– They affect the production of lipids, energy, and vitamins.
– SCFAs can influence appetite and cardiometabolic health.
– They may impact mental health and mood.
– Acetate, propionate, and butyrate have been shown to lower blood pressure in experimental models.
– Production:
– SCFAs are derived from intestinal microbial fermentation of indigestible foods.
– The main SCFAs in the human gut are acetic, propionic, and butyric acid.
– SCFAs serve as the main energy source for colonocytes.
– SCFAs have varying degrees of water solubility, distinguishing them from longer chain fatty acids.
– The lower limit of SCFAs is interpreted with 1, 2, 3, or 4 carbon atoms.
– Absorption:
– SCFAs and medium-chain fatty acids are absorbed through the portal vein during lipid digestion.
– Long-chain fatty acids are packed into chylomicrons and enter lymphatic capillaries.
– SCFAs play a crucial role in gastrointestinal health.
– Butyrate is particularly important for colon health as the primary energy source for colonocytes.
– Acetate can be used by the liver for energy.
– Related Concepts:
– Medium-chain fatty acids (MCFAs) have aliphatic tails of 6 to 12 carbons.
– Long-chain fatty acids (LCFAs) have aliphatic tails of 13 to 21 carbons.
– Very long-chain fatty acids (VLCFAs) have aliphatic tails of 22 or more carbons.
– SCFAs play a significant role in controlling body weight and insulin sensitivity.
– High-fiber diets enriched with different macronutrients affect circulating SCFAs.
Short-chain fatty acids (SCFAs) are fatty acids of two to six carbon atoms. The SCFAs lower limit is interpreted differently, either with 1, 2, 3 or 4 carbon atoms. Derived from intestinal microbial fermentation of indigestible foods, SCFAs in human gut are acetic, propionic and butyric acid. They are the main energy source of colonocytes, making them crucial to gastrointestinal health. SCFAs all possess varying degrees of water solubility, which distinguishes them from longer chain fatty acids that are immiscible.