Colonic fermentation and proximal gastric tone in humans.
OBJECTIVE
Some carbohydrates escape small intestinal absorption, and their presence in the ileum can affect proximal gut motility. Carbohydrates reaching the colon can inhibit gastric and pancreatic secretions. The hypothesis of this study was that colonic fermentation products of carbohydrates (short-chain fatty acids [SCFAs]) affect proximal gut motility and especially gastric tone.


METHODS
Healthy volunteers were studied after oral administration of 20 g lactulose (n = 6) and intracolonic infusions of 20 g lactose (n = 7) and SCFAs (54 mmol/180 mL and 90 mmol/180 mL, respectively). Gastric tone (electronic barostat) and H2 concentrations in exhaled air were simultaneously monitored, and peripheral intestinal peptide levels were measured by specific radioimmunoassays.


RESULTS
After oral lactulose administration (but not after saline), a significant decrease in gastric tone was observed, which rapidly followed the increase in H2 concentrations. Gastric tone also decreased after intracolonic infusions of both lactose and SCFAs; the most marked effect occurred after the highest SCFA dose. No significant changes in the level of plasma oxyntomodulin-like immunoreactivity and glucagon-like peptide 1 were found, whereas the level of peptide YY increased significantly over time, but not differently after saline and test solutions.


CONCLUSIONS
Colonic fermentation of undigestible carbohydrates can inhibit gastric tone, and SCFAs may be responsible for this colonic brake. The role of intestinal peptides, if any, was not identified.
Ropert
A
A
Centre de Recherche en Nutrition Humaine, Laboratoire Fonctions Digestives et Nutrition, Centre Hospitaller Universitaire Hôtel-Dieu, Nantes, France.
Cherbut
C
C
Rozé
C
C
Le Quellec
A
A
Holst
J J
JJ
Fu-Cheng
X
X
Bruley des Varannes
S
S
Galmiche
J P
JP
D000328:Adult; D000704:Analysis of Variance; D001944:Breath Tests; D050260:Carbohydrate Metabolism; D003106:Colon / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005260:Female; D005285:Fermentation; D005769:Gastrointestinal Motility; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides / Q000097:blood; D006801:Humans; D006859:Hydrogen / Q000032:analysis; D008297:Male; D053772:Oxyntomodulin; D019894:Peptide YY; D010455:Peptides / Q000097:blood; D013270:Stomach / Q000502:physiology*
D005232:Fatty Acids, Volatile; D053772:Oxyntomodulin; D010455:Peptides; D019894:Peptide YY; D004763:Glucagon-Like Peptides; D006859:Hydrogen; D052216:Glucagon-Like Peptide 1