Chapter 11. Short-chain Fatty Acids and Human Nutrition

Short-chain fatty acids (SCFA) are the main products of gut bacterial fermentation from carbohydrates but also proteins that escape small intestine digestion. These metabolites are a subset of free fatty acids which can present straight or branched-chain conformations and their role in the interplay between diet, gut microbiota and their impact on our health is an active field of research. SCFA play paramount roles in maintaining intestinal and immune homeostasis in the human body, regulate host energy homeostasis and very recently, they have been considered mediators in the microbiota–gut–brain axis crosstalk. SCFA are influenced both by the dietary components and via diet-mediated changes in microbiota composition; and a wealth of evidence recognizes that they have a major influence on host physiology although their molecular mechanisms of action have not been completely elucidated yet. In this chapter we cover the current evidence about SCFA production and the molecular mechanisms by which SCFA induce a wide range of nutritional and health benefits.