Resistant starch from high amylose maize (HAM-RS2) reduces body fat and increases gut bacteria in ovariectomized (OVX) rats

Obesity (Silver Spring). 2013 May;21(5):981-4. doi: 10.1002/oby.20109.

Abstract

Objective: Obesity after menopause is a health concern for older females. Changes in the microbiota are likely to occur with this condition. Modifying the microbiota with a prebiotic is a plausible strategy for improving the health of menopausal females.

Design and methods: Resistant starch type 2 from high-amylose maize (HAM-RS2) was used as a prebiotic in rats in a 2 × 2 factorial study with two levels of HAM-RS2 (0 or 29.7% of weight of diet) referred to as energy control (EC) and HAM-RS2 diets, respectively; and two levels of surgery, ovariectomized (OVX) and sham.

Results: In a 6-week, postsurgery recovery period, OVX rats gained more body weight with consumption of a similar amount of food. Subsequently, consumption of HAM-RS2 versus EC diets resulted in reduced abdominal fat in both OVX and sham rats; but when normalized for disemboweled body weight (body weight minus GI tract), there was no effect of surgery, only reduction with HAM-RS2. Targeted bacterial populations were estimated that are known to ferment HAM-RS2 or metabolize the products of that initial fermentation. OVX and sham rats demonstrated increased bacterial levels with dietary HAM-RS2 for all bacteria. Additionally, culture techniques and qPCR provided similar results.

Conclusion: This study shows that, as expected, OVX increases adiposity. However, contrary to previous effects seen in obese mice, this did not prevent fermentation of HAM-RS2 and consequently, the fat gain associated with OVX was attenuated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / drug effects*
  • Adipose Tissue / metabolism
  • Animals
  • Bacteria / drug effects*
  • Diet
  • Dietary Fiber / pharmacology
  • Dietary Fiber / therapeutic use
  • Female
  • Fermentation
  • Gastrointestinal Tract / microbiology*
  • Menopause
  • Microbiota
  • Obesity / etiology
  • Obesity / microbiology
  • Obesity / prevention & control*
  • Ovariectomy
  • Plant Preparations / pharmacology
  • Plant Preparations / therapeutic use
  • Prebiotics*
  • Rats, Sprague-Dawley
  • Resistant Starch
  • Starch / analogs & derivatives*
  • Starch / pharmacology
  • Starch / therapeutic use
  • Weight Gain / drug effects
  • Zea mays / chemistry*

Substances

  • Dietary Fiber
  • Plant Preparations
  • Prebiotics
  • Resistant Starch
  • high-amylose maize type 2 resistant starch, maize
  • Starch