High-amylose resistant starch increases hormones and improves structure and function of the gastrointestinal tract: a
Michael J Keenan1, Roy J Martin, Anne M Raggio
1Louisiana State University Agricultural Center, Baton Rouge, LA, USA. mkeenan@agctr.lsu.edu
Journal of Nutrigenetics and Nutrigenomics
|April 21, 2012
Summary
High-amylose maize resistant starch (HAM-RS2) promotes gut health by altering gene expression in rats. Feeding HAM-RS2 supports cell growth and increases gut hormones like GLP-1 and PYY.
Area of Science:
- Nutritional Science
- Molecular Biology
- Gastroenterology
Background:
- Type 2 resistant starch from high-amylose maize (HAM-RS2) enhances gut fermentation and increases expression of proglucagon (GLP-1) and peptide YY (PYY) genes.
- Previous research indicates HAM-RS2 consumption is linked to improved health outcomes.
Purpose of the Study:
- To investigate the comprehensive gene expression changes (upregulation and downregulation) induced by feeding HAM-RS2.
- To identify additional genes affected by HAM-RS2 beyond those related to GLP-1 and PYY.
Main Methods:
- Adult male Sprague Dawley rats were assigned to three dietary groups for 4 weeks: cornstarch control (CC), energy density control (EC), and 30% HAM-RS2 (RS).
- Gene expression profiling was conducted using rat microarrays (approximately 27,000 genes) and validated with quantitative PCR (qPCR) on cecal cell RNA.
- The comparison between RS and EC diets controlled for energy density to isolate the effects of fermentation.
Main Results:
- Microarray analysis revealed that 86% of genes were validated in the RS versus EC comparison.
- Gene expression changes indicated promotion of cell growth, proliferation, differentiation, and apoptosis in the cecum.
- Significant increases in gut hormones GLP-1 and PYY were observed.
Conclusions:
- The observed gene expression patterns suggest that HAM-RS2 consumption leads to improvements in the structure and function of the gastrointestinal tract.
- The production of gut hormones like GLP-1 and PYY may contribute to beneficial health effects extending beyond the GI tract.
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