title: Butyrate esterified to starch is released in the human gastrointestinal tract.
abstract: BACKGROUND
  Short-chain fatty acids (SCFAs) maintain human colonic function and may help prevent colonic disease. A study with ileostomists showed that starches acylated with specific SCFAs largely survive passage through the small intestine, but the percentage released in the colon has not been established.
  
  
  OBJECTIVE
  The objective was to determine the percentage of ingested esterified butyrate released in the human gastrointestinal tract.
  
  
  METHODS
  The study was a randomized, crossover, controlled trial consisting of baseline and four 2-wk periods during which 16 volunteers consumed diets low in resistant starch plus 20 and 40 g cooked high-amylose maize starch (HAMS: HAMS20 or HAMS40) or butyrylated HAMS (HAMSB20 or HAMSB40) daily. HAMSB20 contained 31.8 mmol esterified butyrate. Complete 48-h fecal collections were made on days 2-3 and 12-13 of each period.
  
  
  RESULTS
  Free fecal butyrate concentrations were higher after HAMSB40 than after HAMSB20 (P < 0.005) and HAMS (P < 0.0001) and higher than baseline data (P < 0.0001). Fecal esterified butyrate concentrations were highest in the HAMSB40 (days 12-13; P < 0.0001) group, and concentrations in the HAMSB40 (days 2-3) and HAMSB20 groups were higher than those in the HAMS groups and those at baseline (P < 0.0001). Ingestion of HAMSB20 and HAMSB40 resulted in the release of 26.8 ± 1.0 and 50.2 ± 2.4 mmol butyrate/d (days 12-13) (84.2 ± 3.0% and 79.0 ± 3.1% of total ingested esterified butyrate), respectively, in the gastrointestinal tract. By calculation, ∼57.2% of ingested esterified butyrate was released in the colon. Microbial analysis showed that this release was probably facilitated mainly by Parabacteroides distasonis, which increased in abundance with HAMSB40 (days 12-13) (P < 0.001).
  
  
  CONCLUSIONS
  This study shows that cooked butyrylated starch delivers esterified butyrate to the human colon effectively and has the potential to improve human bowel health. This trial is registered in the Australian Clinical Trials Registry as ACTRN012606000398505.
authors.affiliation: Preventative Health National Research Flagship, Commonwealth Scientific and Industrial Research Organisation, Food and Nutritional Sciences, Adelaide, South Australia, Australia. julie.clarke@csiro.au
authors.forename: Julie M
authors.initials: JM
authors.lastname: Clarke
authors.forename: David L
authors.initials: DL
authors.lastname: Topping
authors.forename: Claus T
authors.initials: CT
authors.lastname: Christophersen
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Bird
authors.forename: Kylie
authors.initials: K
authors.lastname: Lange
authors.forename: Ian
authors.initials: I
authors.lastname: Saunders
authors.forename: Lynne
authors.initials: L
authors.lastname: Cobiac
mesh_terms: D000328:Adult; D000368:Aged; D000688:Amylose / Q000378:metabolism; D002087:Butyrates / Q000378:metabolism*; D018592:Cross-Over Studies; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004032:Diet; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism* / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011788:Quality of Life; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D016037:Single-Blind Method; D013213:Starch / Q000008:administration & dosage* / Q000378:metabolism*; D011795:Surveys and Questionnaires; D055815:Young Adult; D003313:Zea mays
chemical_list: D002087:Butyrates; D004269:DNA, Bacterial; D005232:Fatty Acids, Volatile; D012336:RNA, Ribosomal, 16S; D013213:Starch; D000688:Amylose