title: Butyrylated starch increases large bowel butyrate levels and lowers colonic smooth muscle contractility in rats.
abstract: The short-chain fatty acids acetate, propionate, and butyrate are produced by colonic bacterial fermentation of carbohydrates. Butyrate is important in the regulation of the colonocyte cell cycle and gut motility and may also reduce the risk of large bowel cancer. We have shown that dietary butyrylated starch can deliver butyrate to the large bowel in a sustained manner. We hypothesized that ingestion of butyrylated starch increases large bowel butyrate levels and decreases colonic contractility. Groups of male Sprague-Dawley rats (n = 8) were fed AIN-93G-based diet containing a highly digestible low-amylose maize starch (LAMS) control or 5% or 10% butyrylated LAMS (LAMSB) for 10 days. We found that cecal but not colonic tissue weight as well as cecal and distal colonic digesta weights and fecal output were higher in LAMSB fed rats. Butyrylated LAMS lowered digesta pH throughout the large bowel. Cecal, proximal, and distal colonic butyrate pools and portal venous butyrate concentrations were higher in rats fed LAMSB. Electrically stimulated and receptor-dependent carbachol and prostaglandin E(2)-induced isotonic contractions were lower in isolated intact sections of proximal colon (P < .05) but not the terminal ileum after 10% LAMSB ingestion. These results demonstrated that elevation of butyrate levels in the large bowel of the rat correlated with reduction of contractile activity of the colonic musculature, which may assist in the reabsorption of water and minerals.
authors.affiliation: CSIRO Preventative Health National Research Flagship, Food and Nutritional Sciences, Adelaide, South Australia 5000, Australia.
authors.forename: Balazs H
authors.initials: BH
authors.lastname: Bajka
authors.forename: Julie M
authors.initials: JM
authors.lastname: Clarke
authors.forename: David L
authors.initials: DL
authors.lastname: Topping
authors.forename: Lynne
authors.initials: L
authors.lastname: Cobiac
authors.forename: Mahinda Y
authors.initials: MY
authors.lastname: Abeywardena
authors.forename: Glen S
authors.initials: GS
authors.lastname: Patten
mesh_terms: D000688:Amylose; D000818:Animals; D002087:Butyrates / Q000378:metabolism*; D002432:Cecum; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D003672:Defecation / Q000187:drug effects; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005243:Feces; D006863:Hydrogen-Ion Concentration; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D009929:Organ Size; D011169:Portal Vein / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013213:Starch / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D003313:Zea mays
chemical_list: D002087:Butyrates; D004040:Dietary Carbohydrates; D013213:Starch; D000688:Amylose