Fiber Fermentation Shown to be an Important Mechanism in Weight Management

30/10/06 New research presented at the 2006 Annual Meeting of NAASO, The Obesity Society has showed that fermentation of natural resistant starch derived from corn is an important and previously under-estimated mechanism in weight management with more impact on cellular metabolism and fat deposition than the other mechanisms of dietary fiber. Previously, it had been assumed that energy dilution and bulking were the dominant mechanisms responsible for dietary fiber’s benefits. This discovery has significant implications for weight management, because different types of fiber produce a wide range of fermentation effects.

Dr. Michael Keenan, Dr. Jun Zhou and Dr. Roy Martin were in Boston to explain these results, presented in the technical abstract, “Preliminary Microarray Analysis of Genes from Cecal Cells of Resistant Starch Fed Rats”.1 According to Dr. Michael Keenan, lead author and Professor in the Human Nutrition and Food Division of the Louisiana State University Agricultural Center, a series of studies were conducted to tease apart the dietary fiber effects of energy dilution of the diet from the effects of fermentation. “By comparing diets matched for different variables, we were able to show that the fermentation was the mechanism with the greatest impact of the three mechanisms tested,” he said.

Additional research, published in 2006 by the same team of researchers from Louisiana State University and Pennington Biomedical Research Center had shown that the dietary consumption of Hi-maize resistant starch from National Starch Food Innovation significantly increased important satiety hormones and reduced abdominal fat in animal models. “We have already shown that rats fed resistant starch have increased gut fermentation, increased intestinal expression of peptide YY (PYY) and proglucagon, increased plasma levels of PYY and glucagon-like peptide-1 (GLP-1) and decreased abdominal fat. We believe the fermentation of resistant starch may be an effective natural approach to the treatment of obesity,” he added.

The first study was published in the April issue of Obesity2, the monthly journal of NAASO, the Obesity Society, and the second study was published just last month, also in Obesity3.

Dr Keenan concluded, “The advantage of the resistant starch is that it can be added to foods more readily than non-fermentable fiber. Given that the fermentation effects of non-digestible resistant starch are signaling hormones that release into the blood stream, it may well be time to look further into the overall health benefits that can come from select forms of fiber.”