Oat bran but not a beta-glucan-enriched oat fraction enhances butyrate production in the large intestine of pigs.
Digestibility of polysaccharides and other macronutrients and the metabolic response of the microflora in the large intestine to a low dietary fiber wheat flour diet and three enriched diets with equal amounts of added dietary fiber (oat bran, a beta-glucan-enriched oat fraction and insoluble oat residues) were studied in ileal-cannulated pigs. The digestibility of starch was high in the small intestine (98-100%). At this site of the gastrointestinal tract there was also a significant degradation of mixed linked beta (1 --> 3; 1 --> 4)-D-glucan (beta-glucan) (45-54%), whereas arabinoxylan was quantitatively recovered in ileal effluent. Type and amount of polysaccharides passing the ileal-cecal junction had little effect of the density of microorganism in the large intestine (approximately 10(10) viable counts/g digesta) but did have a high impact on the activity of the flora in colon as measured by the concentration of ATP in digesta. The relative proportion of butyrate in the short-chain fatty acids in the luminal contents of the large intestine was 6.6-8.4% when the low dietary fiber wheat flour diet was fed. However, when either oat bran or insoluble residues were included in the diet, the level was raised to 9.3-11.2%. No effect was seen after the addition of the beta-glucan-enriched fraction. This study showed that arabinoxylan and not beta-glucan in the cell walls of oat bran was responsible for the enhanced butyrate production of oat bran.
Knudsen
K E
KE
National Institute of Animal Science, Department of Animal Physiology and Biochemistry, Tjele, Denmark.
Jensen
B B
BB
Hansen
I
I
D000818:Animals; D002087:Butyrates / Q000378:metabolism*; D004043:Dietary Fiber / Q000378:metabolism / Q000494:pharmacology*; D004063:Digestion / Q000502:physiology*; D002523:Edible Grain; D005227:Fatty Acids / Q000378:metabolism; D005936:Glucans; D007420:Intestine, Large / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D013552:Swine
D002087:Butyrates; D004043:Dietary Fiber; D005227:Fatty Acids; D005936:Glucans