As the sciences involving food, nutrition and eating—yes, eating, which everyone obviously doesn’t consider a science—evolve, we begin to learn more and more about how food is the third most important element to life and living for all humans.
The first most important element is air and the gases it contains, especially oxygen. Second, is water, which should be pure and contamination-free. And the third is food from plant and animal sources that are vibrant, healthy and nutrient-rich.
Unfortunately, in today’s forced chemical lifestyles, all three most important elements are contaminated with all sorts of toxins, especially those that are deliberately placed into the air (industrial pollution and chemtrails from weather geoengineering), water (industrial pollutants, fluoride and water-processing chemicals), and food, which is contaminated from more sources and corporate interests than consumers can imagine.
Food in 2015 does not contain a very healthful nor nutritious profile due to contaminants from genetic modification (GMO) and resultant seeds; herbicides (glyphosate, et al), fertilizers, fungicides, and chemtrails heavy metals (e.g., aluminum, barium, strontium, etc.); pre-harvesting sprays,(e.g., Roundup® used as a pre-harvest staging chemical ); fracking waste-water infused with toxic chemicals that is used to water field crops ; crop silo storage fumigants ; food processing chemicals such as additives, preservatives, artificial colors, ‘free’ MSG , etc.; food packaging chemicals ; foreign food import chemicals and fumigants ; and food irradiation .
Unless consumers are eating certified organically-grown crop foods and sustainably-grown animal foods, they are ingesting untold quantities of unknown toxic chemicals and pollutants served up as food! Back in 2012, the Environmental Working Group estimated that the average American ate 193 pounds of GMO food—yikes! 
Regarding food chemicals, who knows how much an average American eats. The best I can offer is to cite some stats for chemicals sold, which ought to give readers a fair idea of what’s going on—even that’s vague. The U.S. chemical industry produces 15 percent of global chemical shipments, and is the world leader in production and exports . According to Select USA,
Agricultural Chemicals: These play a crucial role in the farm economy and the food processing sector. Thanks to modern agriculture, farmers have doubled the production of world food supplies since 1960, tripled the output of foods like cooking oils and meats, and increased per capita food supplies in the developing world by 25 percent. 
Since we really don’t know what chemicals have been used on the food we buy and eat, learning to read food labels  can be one very helpful step in eliminating many processed food chemicals, but better still, refusing to purchase processed foods, which automatically contain GMOs, is another positive trend. However, the best food-buying practice is to purchase organically-grown foods: fresh, frozen, canned, and packaged/processed organic, certified non-GMO  foods.
So, what does all of the above have to do with “resistant starch”?
Well, the very short, abbreviated answer is that chemicals literally destroy the gut microbiome—the ‘workhorse’ for providing the manufacture of nutrients (certain vitamins) and the transfer of food nutrients into the body’s bloodstream and, ultimately, to tissues and organs. Food and nutrients—not man-made, toxic chemicals—basically are information programs for our genes, is another way to look at it. Food nutrients, not man-made petrochemicals, are what make the human body function healthfully. Without them, we become dis-eased.
Over many years, vitamin deficiency diseases [10, 11] were recognized and identified, which eventually led to artificial food enrichment , i.e., synthetic vitamins, plus added minerals, e.g., iron. Food processing, cooking, storage, and peeling certain plant foods eliminate nutrients too. That’s why it’s best to do “scratch cooking” in order to preserve nutrients and serve food that contains maximum nutritional content.
Now here’s where resistant starches come into play: They provide the nutrients, or food, for the gut bacteria that live and thrive in the human microbiome. When those ‘critters’ are destroyed by chemicals, GMOs, or other “bad” intestinal bugs, the gut gets out of whack and can cause all sorts of distress from diarrhea to pain to bloating to a burning-stinging sensation to nausea and even vomiting. Physicians often will look for all sorts of causes, only to overlook that the microbiome may be devastated and needs to be re-established.
A quick self-help remedy that will bring the microbiome back into balance effectively is to provide the food the microbiome system’s organisms need to re-establish the colony, live and thrive. Those foods are resistant starches that are found in beans, potatoes, and certain grains. Those are the foods that have both soluble and insoluble fibers. It’s the insoluble fibers, which act like prebiotics that feed the microbiome critters, keeping them well fed, healthy and apparently happy.
According to Jordyn Cormier,
There are 3 naturally occurring types of resistant starch:
Type 1 – found in whole grains, seeds, legumes [beans]. It remains undigested due to the protection of the fibrous cell walls.
Type 2 – found in raw starchy foods like green bananas and raw potatoes. However, this starch becomes digestible once heated.
Type 3 – found in starchy foods like rice and potatoes once they are cooked and cooled. The cooling process initiates retrogradation, which causes certain digestible starches to become less accessible to the body and transform into resistant starches. Cold leftovers and brown rice sushi are great examples of this form. 
Cormier also provides a list of “Resistant Starch in Foods,” which I would caution eaters who have gluten intolerance to discern very seriously, since gluten intolerance and leaky gut go hand-in-hand, and eating certain resistant starch foods can cause serious problems. Caution and research are the keys you must use to find relief.
This article is offered as a resource to consider when readers experience gut/stomach/intestinal problems that don’t seem to be resolving or cannot be identified after medical testing. Recently, I’m hearing from quite a few people about their gut problems. When eaters remove canola oil from their diet, they find great relief, as they also experience from removing all GMOs.
Children on the Autism Spectrum Disorder often suffer terribly with debilitating gut pain, which is relieved when GMO foods are removed from their diet. That’s an acknowledged remedy used by holistic/integrative physicians treating ASD patients.
When the gut microbiome  is out of balance, inflammation occurs. According to the U.S. NIH, 60 to 70 million people in the USA are afflicted with all sorts of digestive diseases. In 1998, 15.3 million suffered with Irritable Bowel Syndrome (IBS). This NIH link provides a breakdown of digestive diseases, which definitely can be managed, treated, and even healed, by the type of food one eats, plus taking a daily probiotic supplement.
Eating out in restaurants for pleasure or while traveling can be extremely difficult and challenging for anyone with gluten sensitivities, food allergies, or Crohn’s disease. There’s an online Android app “Find Me Gluten Free” readers may want to know about. Also, there’s a “Gluten Free Registry™” online with a map of the USA and also a link to a color-coded “Gluten Free World Map.”
As Hippocrates said so long ago [c. 460-375 BCE], “Let food be thy medicine and medicine be thy food.” We have to believe it!
List of Chemicals Used in Food Processing
50 Jawdropping Toxic Food Ingredients & Artificial Additives to Avoid
Effect of Organic Diet Intervention on Pesticide Exposures in Young Children Living in Low-Income Urban and Agricultural Communities
Environ Health Perspect; DOI:10.1289/ehp.1408660 http://ehp.niehs.nih.gov/1408660/
Catherine J Frompovich (website) is a retired natural nutritionist who earned advanced degrees in Nutrition and Holistic Health Sciences, Certification in Orthomolecular Theory and Practice plus Paralegal Studies. Her work has been published in national and airline magazines since the early 1980s. Catherine authored numerous books on health issues along with co-authoring papers and monographs with physicians, nurses, and holistic healthcare professionals. She has been a consumer healthcare researcher 35 years and counting.
Catherine’s latest book, published October 4, 2013, is Vaccination Voodoo, What YOU Don’t Know About Vaccines, available on Amazon.com.
Her 2012 book A Cancer Answer, Holistic BREAST Cancer Management, A Guide to Effective & Non-Toxic Treatments, is available on Amazon.com and as a Kindle eBook.
Two of Catherine’s more recent books on Amazon.com are Our Chemical Lives And The Hijacking Of Our DNA, A Probe Into What’s Probably Making Us Sick (2009) and Lord, How Can I Make It Through Grieving My Loss, An Inspirational Guide Through the Grieving Process (2008)