HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vogt, J. A Articles by Wolever, T. M. Search for Related Content PubMed PubMed Citation Articles by Vogt, J. A Articles by Wolever, T. M. Agricola Articles by Vogt, J. A Articles by Wolever, T. M.

L-Rhamnose increases serum propionate in humans^1,2,3

¹ From the University of Toronto, Toronto, Canada (JAV, PBP, TMSW); St Michael's Hospital, Toronto, Canada (TMSW); and The Hospital for Sick Children, Toronto, Canada (PBP).

Background: Acetic and propionic acids are produced by colonic bacterial fermentation of unabsorbed carbohydrates and are absorbed into the portal circulation. From there, they travel to the liver, where acetate is a lipogenic substrate and propionate can inhibit lipogenesis. The extent to which peripheral blood short-chain fatty acid concentrations reflect differences in colonic fermentation is uncertain. The unabsorbed sugar lactulose produces mainly acetate when fermented in vitro, whereas L-rhamnose yields propionate.

Objective: The objective of the study was to ascertain whether ingestion of L-rhamnose and lactulose would have different acute effects on peripheral acetate and propionate concentrations and on breath hydrogen and methane concentrations.

Design: Twenty-two subjects were fed 25 g L-rhamnose, lactulose, or glucose on 3 separate occasions in a randomized crossover design. Blood and breath samples were collected hourly for 12 h.

Results: Serum propionate was significantly higher with ingestion of L-rhamnose than with that of lactulose or glucose (P < 0.001). The area under the curve for serum acetate was significantly higher with ingestion of lactulose than with that of glucose (P < 0.03). The ratio of serum acetate to propionate was significantly higher with ingestion of lactulose than with that of glucose or L-rhamnose (P < 0.01). Breath hydrogen was significantly higher with ingestion of lactulose than with that of L-rhamnose or glucose (P < 0.0001).

Conclusions: The selective increases in serum acetate and propionate concentrations in humans were obtained by feeding specific fermentable substrates. Presumably, these changes in serum concentrations reflect changes in colonic production. Selective alteration of colonic fermentation products could yield a new mechanism for modifying blood lipids.

Key Words: Propionate • short-chain fatty acids • colon • fermentation • L-rhamnose

This article has been cited by other articles:

				J. M. W. Wong and D. J. A. Jenkins Carbohydrate Digestibility and Metabolic Effects J. Nutr., November 1, 2007; 137(11): 2539S - 2546S. [Abstract] [Full Text] [PDF]

				J. A. Vogt, K. B. Ishii-Schrade, P. B. Pencharz, P. J. H. Jones, and T. M. S. Wolever L-Rhamnose and Lactulose Decrease Serum Triacylglycerols and Their Rates of Synthesis, but Do Not Affect Serum Cholesterol Concentrations in Men J. Nutr., August 1, 2006; 136(8): 2160 - 2166. [Abstract] [Full Text] [PDF]

				J. A Vogt, K. B Ishii-Schrade, P. B Pencharz, and T. M. Wolever L-Rhamnose increases serum propionate after long-term supplementation, but lactulose does not raise serum acetate Am. J. Clinical Nutrition, November 1, 2004; 80(5): 1254 - 1261. [Abstract] [Full Text] [PDF]