title: Effect of acetate and propionate on calcium absorption from the rectum and distal colon of humans.
abstract: To determine the effects of acetate and propionate on calcium absorption from the human distal colon and rectum, six healthy human subjects were given rectal infusions containing 50 mmol CaCl2/L on four separate occasions. Addition of 56.3 mmol acetate/L, 18.7 mmol propionate/L, or acetate and propionate together increased calcium disappearance (expressed as the change in the ratio of calcium to polyethylene glycol) from -5.5 +/- 1.4 to -22.6 +/- 2.8, -23.2 +/- 3.2, and -19.7 +/- 4.6, respectively; P < 0.05. To determine the effects of different acetate and propionate concentrations, six different subjects were studied further. The effects of 18.7 or 56.3 mmol acetate/L on calcium absorption were the same as those of 18.7 mmol propionate/L (-15.7 +/- 1.4), and less than those of 56.3 mmol propionate/L (-20.3 +/- 2.4, P < 0.05). We conclude that both acetate and propionate enhance calcium absorption from the human distal colon, but that propionate has a greater effect at higher concentrations. Further studies are needed to determine the mechanism of calcium absorption from the colon.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Canada.
authors.forename: T P
authors.initials: TP
authors.lastname: Trinidad
authors.forename: T M
authors.initials: TM
authors.lastname: Wolever
authors.forename: L U
authors.initials: LU
authors.lastname: Thompson
mesh_terms: D000085:Acetates / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D002118:Calcium / Q000493:pharmacokinetics*; D003106:Colon / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D011422:Propionates / Q000008:administration & dosage / Q000494:pharmacology*; D012007:Rectum / Q000187:drug effects / Q000378:metabolism*; D012965:Sodium Chloride / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000085:Acetates; D011422:Propionates; D012965:Sodium Chloride; D002118:Calcium