Role of Resistant Starch in Improving Gut Health, Adiposity, and Insulin Resistance

Abstract

The realization that low-glycemic index diets were formulated using resistant starch led to more than a decade of research on the health effects of resistant starch. Determination of the metabolizable energy of the resistant starch product allowed for the performance of isocaloric studies. Fermentation of resistant starch in rodent studies results in what appears to be a healthier gut, demonstrated by increased amounts of short-chain fatty acids, an apparent positive change in the microbiota, and increased gene expression for gene products involved in normal healthy proliferation and apoptosis of potential cancer cells. Additionally, consumption of resistant starch was associated with reduced abdominal fat and improved insulin sensitivity. Increased serum glucagon-like peptide 1 (GLP-1) likely plays a role in promoting these health benefits. One rodent study that did not use isocaloric diets demonstrated that the use of resistant starch at 8% of the weight of the diet reduced body fat. This appears to be approximately equivalent to the human fiber requirement. In human subjects, insulin sensitivity is increased with the feeding of resistant starch. However, only 1 of several studies reports an increase in serum GLP-1 associated with resistant starch added to the diet. This means that other mechanisms, such as increased intestinal gluconeogenesis or increased adiponectin, may be involved in the promotion of improved insulin sensitivity. Future research may confirm that there will be improved health if human individuals consume the requirement for dietary fiber and a large amount of the fiber is fermentable.

Resistant starches for the management of metabolic diseases

“…Since then, considerable effort has also been devoted to investigating the metabolic effects of RS using both human clinical trials and animal models [5*;6*]. In particular, several recent studies have strengthened the concept that RS confer metabolic benefits.…”

“…RS remain intact until reaching the distal small and large intestines—here, they can be fermented by the microbiota, ultimately modulating both microbial composition and activity [18–23]. Consequently, the gut microbiota has been proposed as a key component in mediating the metabolic benefits of RS [5*;14**]. …”

“…RS-mediated improvements in insulin sensitivity have been observed without a concomitant impact on GLP-1 levels [5]. In the Bodinham et al study, feeding RS2 to T2D patients for 12 weeks lowered fasting GLP-1 levels but increased GLP-1 postprandial excursion during a meal tolerance test [6].…”

“…RS can easily replace regular starch in baked goods and, by being non-digestible, can reduce both the caloric density and glycemic index of food products. However, RS exert physiological effects that go beyond resistance to digestibility, including modulation of satiety perception, dyslipidemia, insulin sensitivity, and glycemic control in both healthy and obese volunteers as well as in patients with metabolic syndrome [5*;6*;7**]. …”

Role or Synergistic Interaction of Adenosine and Vitamin D3 Alongside High-Intensity Interval Training and Isocaloric Moderate Intensity Training on Metabolic Parameters: Protocol for an Experimental Study (Preprint)

“…Plant based substances [4,10,11] and medicines [12][13][14][15][16] have been proposed as strategic treatment and preventive measures for obesity. Presently, one of the most challenging issues in the field of pharmacy is the discovery of the most effective anti-obesity intervention with the least negative side effects on humans.…”