title: Short chain fatty acids exchange across the gut and liver in humans measured at surgery.
abstract: OBJECTIVE
  Short chain fatty acids (SCFAs; acetate, propionate and butyrate) are important energy sources for colonocytes and are assumed to play a key role in gut health. Local effects of SCFAs have been investigated, but less is known about whole body metabolism of these SCFAs. The aim of the present study was to quantify the role of the gut and liver in interorgan exchange of SCFAs in humans in vivo.
  
  
  METHODS
  Twenty-two patients undergoing major upper abdominal surgery were studied. Blood was sampled from a radial artery, the portal and a hepatic vein. Portal, splanchnic and arterial blood flow was measured using intra-operative Duplex ultrasonography. SCFAs were measured on a liquid chromatography system combined with mass spectrometry.
  
  
  RESULTS
  SCFAs were released by the gut, 34.9 (9.1) micromol kg bodyweight(-1)h(-1). SCFAs uptake by the liver was significant for propionate and butyrate; -5.6 (1.3) and -3.8 (1.6) micromol kg bodyweight(-1)h(-1) (p=0.0002 and p=0.03) respectively and counterbalanced gut release. Liver uptake of acetate was not significant, -5.2 (6.6) micromol kg bodyweight(-1)h(-1) (p=0.434). Splanchnic (i.e., gut+liver) SCFAs release was significant for acetate and propionate, 17.3 (7.3) and 1.2 (0.4) micromol kg bodyweight(-1)h(-1) (p=0.027 and p=0.0038), respectively. Splanchnic release of butyrate was not significantly different from zero (1.9 (1.2) micromol kg bodyweight(-1)h(-1), p=0.129). BMI and previous colonic resection did not affect gut release of SCFAs.
  
  
  CONCLUSIONS
  This is the first in vivo study on the role of the gut and liver in SCFAs exchange in humans in vivo. It is shown that intestinal SCFAs release by the gut is equalled by hepatic uptake.
authors.affiliation: Department of Surgery, Nutrition and Toxicology Research Institute Maastricht, Maastricht University Medical Centre, PO Box 5800, 6202 AZ, Maastricht, The Netherlands.
authors.forename: Johanne G
authors.initials: JG
authors.lastname: Bloemen
authors.forename: Koen
authors.initials: K
authors.lastname: Venema
authors.forename: Marcel C
authors.initials: MC
authors.lastname: van de Poll
authors.forename: Steven W
authors.initials: SW
authors.lastname: Olde Damink
authors.forename: Wim A
authors.initials: WA
authors.lastname: Buurman
authors.forename: Cornelis H
authors.initials: CH
authors.lastname: Dejong
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D015992:Body Mass Index; D005232:Fatty Acids, Volatile / Q000097:blood / Q000378:metabolism*; D005260:Female; D006503:Hepatic Veins; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000098:blood supply*; D007432:Intraoperative Period; D008099:Liver / Q000098:blood supply* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011169:Portal Vein; D017534:Radial Artery; D012039:Regional Blood Flow; D013154:Spleen / Q000098:blood supply; D018608:Ultrasonography, Doppler
chemical_list: D005232:Fatty Acids, Volatile