TY - JOUR

T1 - The influence of ispaghula husk and lactulose on the in viva and the in vitro production capacity of short-chain fatty acids in humans

AU - Rasmussen, H. Sandvad

AU - Holtug, Klavs

AU - Andersen, Jens Rikardt

AU - Krag, Einar

AU - Mortensen, Per Brøbech

N1 - (Ekstern)

PY - 1987

Y1 - 1987

N2 - To evaluate factors influencing the short-chain fatty acid (SCFA) concentrations in stools, three different experiments were performed: 1) faecal concentrations of SCFA at defecation were determined by gas liquid chromatography in nine healthy volunteers on a free diet. SCFAs were 114 ± 15.0 mmol/l (means ± SD). The coefficient of variation (CV) of the assay was 4-15% the intraindividual CV 12-33% and the interindividual CV 11-29% On incubation of faeces at 37°C concentrations of SCFA doubled in 6h and rose fourfold in 72 h. 2) In three volunteers the experiments were extended by adding ispaghula husk or lactulose to the diet for two 14-day periods each; no change in faecal SCFA concentrations was seen, either at defecation or after incubation. 3) When ispaghula husk or lactulose was added to faeces in an in vitro incubation system, the concentrations of SCFA were five times higher than those of controls. We conclude that instant handling of faeces is essential for determinations of SCFA concentrations to obtain interpretable and comparable results; that determination of total SCFA output is of limited value; that addition of fibre to the diet does not influence faecal SCFA Concentrations; and that the capacity for SCFA production in faeces is large provided a sufficient amount of substrate is available.

AB - To evaluate factors influencing the short-chain fatty acid (SCFA) concentrations in stools, three different experiments were performed: 1) faecal concentrations of SCFA at defecation were determined by gas liquid chromatography in nine healthy volunteers on a free diet. SCFAs were 114 ± 15.0 mmol/l (means ± SD). The coefficient of variation (CV) of the assay was 4-15% the intraindividual CV 12-33% and the interindividual CV 11-29% On incubation of faeces at 37°C concentrations of SCFA doubled in 6h and rose fourfold in 72 h. 2) In three volunteers the experiments were extended by adding ispaghula husk or lactulose to the diet for two 14-day periods each; no change in faecal SCFA concentrations was seen, either at defecation or after incubation. 3) When ispaghula husk or lactulose was added to faeces in an in vitro incubation system, the concentrations of SCFA were five times higher than those of controls. We conclude that instant handling of faeces is essential for determinations of SCFA concentrations to obtain interpretable and comparable results; that determination of total SCFA output is of limited value; that addition of fibre to the diet does not influence faecal SCFA Concentrations; and that the capacity for SCFA production in faeces is large provided a sufficient amount of substrate is available.

KW - Dietary fibre

KW - Fermentation

KW - Lactulose

KW - Production capacity

KW - Short-chain fatty acids

UR - http://www.scopus.com/inward/record.url?scp=0023275090&partnerID=8YFLogxK

U2 - 10.3109/00365528708991482

DO - 10.3109/00365528708991482

M3 - Journal article

C2 - 3037683

AN - SCOPUS:0023275090

VL - 22

SP - 406

EP - 410

JO - Scandinavian Journal of Gastroenterology. Supplement

JF - Scandinavian Journal of Gastroenterology. Supplement

SN - 0085-5928

IS - 4

ER -