title: Effect of chronic dietary fibre supplementation on colonic pH in healthy volunteers.
abstract: Dietary fibre supplementations studies to evaluate the effect of dietary fibre on colonic and faecal pH have relied on the use of the unabsorbed disaccharide and osmotic laxative lactulose. We studied the effect of chronic dietary fibre supplementation on colonic pH in healthy British volunteers who consumed a normal mixed diet but who consumed a normal mixed diet but who were asked to double their daily intake of dietary fibre from their usual fibre sources. The median dietary fibre intake of the 5 male volunteers was 17.5 g/day. This was doubled to 34.4 g/day. The pH in all the parts of the colon decreased progressively during the period of study, being lowest at the end of two weeks of fibre supplementation. The pH returned to the presupplementation values within two weeks of cessation of fibre supplementation. This study has shown that the effect of dietary fibre on colonic pH is short-lived and therefore its use for dietary intervention in large bowel diseases should be indefinite.
authors.affiliation: Department of Surgery, University of Ghana Medical School, Accra, Ghana.
authors.forename: S B
authors.initials: SB
authors.lastname: Naaeder
authors.forename: D F
authors.initials: DF
authors.lastname: Evans
authors.forename: E Q
authors.initials: EQ
authors.lastname: Archampong
mesh_terms: D000328:Adult; D003106:Colon / Q000187:drug effects* / Q000378:metabolism*; D004043:Dietary Fiber / Q000494:pharmacology*; D002523:Edible Grain; D005243:Feces / Q000737:chemistry; D005638:Fruit; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014675:Vegetables