NCSBTIFN Shortchain fatty acid project TNO UMCG WUR

NCSB/TIFN Short-chain fatty acid project TNO, UMCG, WUR Barbara Bakker Albert A. de Graaf Vitor Martins dos Santos

Transorgan SCFA metabolism • In vitro and animal models to probe SCFA metabolism e. g. 50 m. M butyrate bacterial production SCFA colon lumen substrate SCFA project - WP 2 Liver metabolism Colonic metabolism SCFA colon cells portal vein SCFA liver hepatic vein Whole body metabolism SCFA arterial pool e. g. 10 u. M butyrate ? SCFA

Structure of the project SCFA project – WP 1

WP 1 - Gut microbiomics of SCFA metabolism & metagenome-scale metabolic models Vitor dos Santos Purpose The construction of genome-scale metabolic models of the gut microbiota, focusing on SCFA metabolism and the metabolic reconstruction and subsequent classification of metabolism of all sequenced species found in the gut, allowing for a reconstruction of the gut food web SCFA project – WP 1

WP 1 – Metagenome pathway analysis of gut microbial consortia, for SCFA production SCFA project – WP 1

WP 2 - Purpose Develop computational models that allow to predict the rates of intestinal SCFA production and the rates of the main SCFAderived metabolic processes in the host, using knowledge on the composition of the intestinal microbiota and the given substrate • Focus on processes associated with the proximal colon as this is the principal site of SCFA production • Use available data (acquired in TIFN C-012 “Microbe-mediated gut metabolism” project) SCFA project - WP 2

WP 2 Data type overview – TIM-2 in vitro model e. g. 50 m. M butyrate [U-13 C] starch, inulin, lactose bacterial production SCFA colon lumen Various other unlabeled carbohydrate substrates SCFA project - WP 2 substrate HITchip data RNA-SIP profiles SCFA kinetics SCFA isotopomers

WP 2 Data type overview - mouse [1 -13 C]butyrate SCFA colon lumen Liver metabolism Colonic metabolism SCFA colon cells portal vein SCFA liver hepatic vein Whole body metabolism SCFA arterial pool e. g. 10 u. M butyrate ? SCFA substrate SCFA project - WP 2 SCFA isotopomers Amino acid isotopomers + kinetics

Potential isotopic markers of colonocytes TCA cycle activity 2 [1 -13 C] butyrate 1 -13 C aspartate & 4 -13 C aspartate 1 4 1 5 -13 C glutamate 5 1 3 1 -13 C glutamate & SCFA project - WP 2 13 CO 2

WP 2 Data type overview – pig [1 -13 C]butyrate Different infusion rates SCFA colon lumen SCFA portal vein colon cells Levels of [1 -13 C]butyrate SCFA project - WP 2 Liver metabolism Colonic metabolism SCFA liver hepatic vein Whole body metabolism SCFA arterial pool e. g. 10 u. M butyrate ? SCFA

WP 2 - The regulation of SCFA production Experimental Computational • unlabeled substrates in TIM-2 SCFA profile analysis and HITchip analysis • Multivariate “substrate characteristics SCFA profile” prediction model • 13 C • Correlation map of microbiota composition and SCFA profile labeled substrates in TIM-2 bacterial pathway kinetics and SIP analysis 13 C labeled caecal bolus of butyrate metabolism • 13 C labeled caecal infusion of butyrate transorgan absorption/metabolism of butyrate in pig • Bottom-up ODE models of fatty acid production • Extend visibility of bacterial & colonocyte fluxes from 13 C experiments • Regulation Analysis of interorgan butyrate metabolism

WP 3 + 4 (Groningen) The role of SCFA in mouse metabolism Short-chain fatty acids SCFA metabolism? CO 2 +ATP/ Elongation, storage Regulation? Carbohydrate and (long-chain) fatty-acid fluxes

The role of SCFA in mouse metabolism Experimental Computational • 13 C labelled rectal infusion of acetate / propionate/ butyrate fate of SCFA • Extend visibility of fluxes from 13 C experiments • 13 C • Stoichiometric map of mouse fatty acid metabolism, incl. SCFA labelled tracers (glucose, glycerol, acetate) infusion in blood regulatory effect of SCFA on central energy metabolism • Bottom-up ODE models of fatty acid oxidation and the regulatory role of SCFA • Regulation Analysis • Modular Control Analysis

Glucose le ssib e c c a blood Peripheral disposal [1 -13 C]-acetate Glucose-6 -P Glycogen glycerol Intestine CHOL Pyruvate alanine Acetyl-Co. A lactate FFA

Calculations