a1 INRA, U1079, Unité Mixte de Recherche - Système Elevage, Nutrition Animale et Humaine (UMR SENAH), Domaine de la Prise, 35590 Saint-Gilles, France
a2 ONIRIS, UPSP Nutrition & Endocrinologie, Nantes F-44307, France
a3 Université de Nantes, Angers, Le Mans, France
a4 Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
a5 Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
Butyrate is a natural substance present in biological liquids and tissues. The present paper aims to give an update on the biological role of butyrate in mammals, when it is naturally produced by the gastrointestinal microbiota or orally ingested as a feed additive. Recent data concerning butyrate production delivery as well as absorption by the colonocytes are reported. Butyrate cannot be detected in the peripheral blood, which indicates fast metabolism in the gut wall and/or in the liver. In physiological conditions, the increase in performance in animals could be explained by the increased nutrient digestibility, the stimulation of the digestive enzyme secretions, a modification of intestinal luminal microbiota and an improvement of the epithelial integrity and defence systems. In the digestive tract, butyrate can act directly (upper gastrointestinal tract or hindgut) or indirectly (small intestine) on tissue development and repair. Direct trophic effects have been demonstrated mainly by cell proliferation studies, indicating a faster renewal of necrotic areas. Indirect actions of butyrate are believed to involve the hormono–neuro–immuno system. Butyrate has also been implicated in down-regulation of bacteria virulence, both by direct effects on virulence gene expression and by acting on cell proliferation of the host cells. In animal production, butyrate is a helpful feed additive, especially when ingested soon after birth, as it enhances performance and controls gut health disorders caused by bacterial pathogens. Such effects could be considered for new applications in human nutrition.
Abbreviations: GI, gastrointestinal; GIT, gastrointestinal tract; GLP, glucagon-like peptide; GPR, G protein-coupled receptor; HSP, heat-shock protein; MCT, monocarboxylate transporter; RS, resistant starch; SMCT, Na-coupled monocarboxylate transporter