title: Intestinal absorption of oestrogen: the effect of altering transit-time.
abstract: OBJECTIVE
  The mechanism by which a high fibre diet may reduce serum oestrogens is unknown. We hypothesized that time is a rate-limiting factor in oestrogen absorption from the colon so that changes in colonic transit-rate affect the proportion of oestrogen that is deconjugated and/or absorbed.
  
  
  OBJECTIVE
  To determine if alteration of intestinal transit rate would influence the absorption of an oral dose of oestradiol glucuronide.
  
  
  METHODS
  Twenty healthy postmenopausal women recruited by advertisement.
  
  
  METHODS
  Department of Medicine, Bristol Royal Infirmary.
  
  
  METHODS
  Volunteers consumed, in turn, wheat bran, senna, loperamide and bran shaped plastic flakes, each for 10 days with a minimum 2 week washout period between study periods, dietary intake being unchanged. Before and in the last 4 days of each intervention whole-gut transit-time, defecation frequency, stool form, stool beta-glucuronidase activity, stool pH and the absorption of a 1.5 mg dose of oestradiol glucuronide were measured.
  
  
  RESULTS
  Wheat bran, senna and plastic flakes led to the intended reduction in whole-gut transit-time, increase in defecatory frequency and increase in stool form score. Loperamide caused the opposite effect. The length of time the absorbed oestrogen was detectable in the serum fell with wheat bran and senna, although this was only significant for oestradiol. Oestrone, but not oestradiol, was detectable for a longer time with loperamide. Plastic flakes had no effect on either oestrogen. Areas under the curve did not change significantly but tended to fall with the three transit-accelerating agents and to rise with loperamide.
  
  
  CONCLUSIONS
  Our data indicate there is likely to be an effect of intestinal transit on the absorption of oestrogens but more refined techniques are needed to characterize this properly.
authors.affiliation: University Department of Medicine, Bristol Royal Infirmary, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Lewis
authors.forename: R E
authors.initials: RE
authors.lastname: Oakey
authors.forename: K W
authors.initials: KW
authors.lastname: Heaton
mesh_terms: D004043:Dietary Fiber; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D004970:Estrone / Q000097:blood / Q000378:metabolism; D005260:Female; D005772:Gastrointestinal Transit; D006801:Humans; D007408:Intestinal Absorption; D008875:Middle Aged
chemical_list: D004043:Dietary Fiber; D004970:Estrone; D004958:Estradiol