RS may help to lower blood cholesterol and fats, while also decreasing the production of new fat cells (the latter has only been shown in rats). Also, since SCFAs can inhibit the breakdown of carbohydrates in the liver, RS can increase the amount of fat we utilize for energy.
Several studies have shown alterations in the gut microbiome in association with obesity, which subsequently change towards that seen in lean individuals with weight loss. For example, one study demonstrated that the relative composition of the gut microbiota of two predominate beneficial bacteria,Bacteroidetes and Firmicutes, varied considerably in association with body composition. Specifically, obese individuals often have a higher proportion ofFirmicutes to Bacteroidetes, which may be reversed with weight loss, gastric bypass surgery, or treatment with prebiotics. However, not all studies confirm a significant or measurable change in the composition of the microbiome in obese compared to lean individuals, and further studies are needed.
RS can help to feel satisfied longer. SCFAs can trigger the release of hormones that reduce the drive to eat (leptin, peptide YY, glucagon like peptide). After someone starts eating more RS, it may take up to one year for gut hormones to adapt. RS slows the amount of nutrients released into the bloodstream, which keeps appetite stable.
Insulin resistance and chronically elevated blood glucose are associated with a host of chronic diseases, including metabolic syndrome. Several studies have shown that RS may improve insulin sensitivity, and decrease blood glucose levels in response to meals. In one study, consumption of 15 and 30 grams per day of resistant starch showed improved insulin sensitivity in overweight and obese men, equivalent to the improvement that would be expected with weight loss equal to approximately 10% of body weight. Further, RS has been shown to exert a "second meal effect." This means that not only does RS beneficially decrease the blood glucose response at the time it's consumed, but, somewhat surprisingly, blood glucose and insulin levels also rise less than would otherwise be expected with the subsequent meal.
RS intake allows for increased production of butyrate by our gut microbes. Butyrate acts as a powerful anti-inflammatory agent for the colonic cells, and functions to improve the integrity of our gut by decreasing intestinal permeability and therefore keeping toxins in the gut and out of the bloodstream. RS may help alleviate irritable bowel syndrome, diverticulitis, constipation, and ulcerative colitis. RS can add bulk and water to the stool, aiding in regular bowel movements. SCFAs can help to prevent the development of abnormal bacterial cells in the colon and enhance mineral absorption (especially calcium).
Since RC has less energy (calories) per gram than other starches, it can help us eat less. And consuming more RS may have a thermal effect in the body.
For those receiving treatment for hiarrhea, RS can assist in the rehydration process (since it can normalize bowel function).
Consuming RS can influence the production of immune cells and inflamatory compounds in the gut.