Effects of two contrasting dietary fibres on starch digestion, short-chain fatty acid production and transit time in rats
✍ Scribed by Philip J Harris; Clifford Tasman-Jones; Lynnette R Ferguson
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 107 KB
- Volume
- 80
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
Dietary ®bres may cause dietary starch to escape digestion in the small intestine and enter the large intestine. If this results from the dietary ®bres reducing the gastrointestinal transit time, those dietary ®bres that reduce this the most would be expected to cause the most starch to escape digestion. We tested in rats the relative abilities of two contrasting dietary ®bres, apple pectin (a soluble dietary ®bre) and wheat straw (an insoluble, ligni®ed dietary ®bre), to reduce the whole gut transit time and to cause dietary starch to escape digestion. We provided male Wistar rats with a control, modi®ed AIN-76 2 diet containing 20% fat but no dietary ®bre, and with this diet containing 10% dietary ®bre; the dietary ®bre replaced the equivalent weight of starch in the control diet. Both dietary ®bres, but particularly wheat straw, reduced the transit time compared with the ®bre-free control diet. Pectin, but not wheat straw, resulted in substantial amounts of starch in the caecal contents. This effect may result from the pectin increasing the viscosity of the digesta or causing it to gel. Large amounts of short-chain fatty acids were found only in the caeca of rats provided with pectin.