An Overview of Digestive Health

Normal health is not possible without normal digestive function. Normal digestion can be compromised by:

Gut-Offending Foods

There is no perfect food and all foods carry at least some potential for harm to the digestive system. That being said, some foods carry a higher potential for harm than others.

By far, the most irritating foods to the gut are seeds (grains, beans, nuts). Think about it; the purpose of any seed is too grow a new plant, not to nourish some other creature. Not surprisingly, plants install substances to deter consumption.

The primary deterrents are proteins called lectins. Lectins irritate the cells lining the intestines of animals. There are many different types of lectins, some more irritating than others. Lectins are very stable proteins and are only minimally broken down by stomach acid. Extensive boiling will break them down, but not baking. Sprouting and fermenting also helps break down lectins.

Of all the grains, wheat contains the most irritating lectins. Wheat also contains gluten, a special protein for supplying amino acids to the sprouting plant. Because gluten is foreign to animals, it is very irritating to the gut and very allergenic. (See Wheat Sensitivity for more information.)

Other grains also contain lectins and storage proteins, but are less irritating than wheat. Rice contains the least irritating proteins and is well tolerated by most people.

Bean lectins are also extremely irritating to the gut. Raw beans are actually poisonous without being cooked. Fermented soybean products are generally tolerated well. Lentils and mung beans are the easiest to digest. All beans should be thoroughly washed, soaked, and boiled before consumption.

Nuts are generally well tolerated by most people, but can cause gut irritation if digestive problems have long been present.

Night-shade vegetables (tomatoes, potatoes, peppers, eggplant) also contain high concentrations of irritating lectins.

All seeds can harbor toxic mold, especially wheat and corn. Any foods, with time (even in the refrigerator) will start growing mold. Dairy products (with the exception of cultured yogurt/kefir) are notorious for growing toxic mold.

Dairy is a challenge for people who lack the enzyme that breaks down lactose. Milk proteins are also very allergenic for some people.

Meat proteins are not irritating to the gut, but high concentrations of protein can also be a challenge to the digestive system. Red meat laden with saturated fat is the hardest meat to digest. Poultry and fish are easier for most people to digest.

Cooked vegetables are generally the best tolerated of all foods. Cooking (ideally steaming) breaks down fiber and releases nutrients. Cooking also kills mold, microbes, and parasite eggs.

Chronic Stress

Diet is not the only factor that affects the digestive process. When faced with a threat, the body goes into high alert. Alert mode, often called the fight-or-flight response, prepares the body for dealing with a threat such as a confrontation or emergency. Resources of the body are shifted toward dealing with the threat. Everyday maintenance and intestinal functions are temporarily placed on hold until the threat passes or is resolved.

In the modern world, the perception of threat is always present; just going about life is stressful. People come to accept chronic stress as a normal part of daily life because they do not know anything different.

Of all systems in the body, the gastrointestinal system is the most affected. Chronic stress inhibits gastrointestinal function and slows the movement of food materials through the gut.

Secretion of digestive enzymes is inhibited and the digestive process is compromised. Everything gets backed up. Slowed emptying of the stomach causes acid to splash into the lower esophagus causing burning and the erosive properties of lectin-loaded foods are compounded. Chronic stomach irritation and erosions are a common consequence.

The flow of bile through the liver and gallbladder is slowed. This commonly results in liver congestion and formation of stones in the gallbladder. Removal of toxins from the body is inhibited.

Gut Microbiome Imbalance

Processed food products, mostly made from wheat, corn, and soybeans, are not only loaded with lectins, but also with starch and sugar; much more than the body can use or absorb. Undigested starches and sugar are fodder for intestinal bacteria. Overgrowth of bacteria in the small intestine (referred to as SIBO, Small Intestine Bacterial Overgrowth) results in symptoms of bloating, trapped gas, and chronic abdominal discomfort.

Starches and sugar also stimulate growth of yeast. Yeast are always present in the intestines, but growth is normally inhibited by friendly bacteria. The presence of undigested carbohydrates allow yeast to flourish. Toxins produced by yeast overgrowth make a person feel terrible all over.

Leaky Gut

A combination of lectin-loaded food, inhibited intestinal motility (by chronic stress), and bacterial overgrowth compromises the protective barrier of the intestine. Once the intestinal mucosa has been totally compromised, foreign proteins “leak” across into the bloodstream in high concentrations (including lectins and other plant and animal proteins not broken down by normal digestion). This is commonly referred to as leaky gut.

Foreign proteins stimulate the immune system into overdrive (especially lectins). Lectins stimulate antibody production, activate chemical messengers of the immune system, and initiate histamine response (classic allergic response).

Beyond lectins, all foods contain proteins that can potentially cause sensitivity. Sensitivity to food proteins only occurs in the presence of leaky gut. Sensitivity to a particular food can be mild to severe. Multiple sensitivities are common.

The most common food sensitivities include: wheat, dairy, corn, nuts, yeast, tomatoes, citrus, eggs, soy, bananas, beans, potatoes, pork, and beef.

System-wide symptoms associated with food sensitivities occur 1 to 12 hours after eating and include fatigue (especially 1-2 hours after eating), brain fog, feeling flu-like, muscle pain, joint pain, anemia, and a wide range of other nonspecific symptoms.

Learn more Leaky Gut »


Chronic stress and eating on the run also inhibit function in the colon. Lectin-loaded food damages the colon and slows movement even more. This allows further overgrowth of harmful strains of bacteria, resulting in gas and discomfort. Initially this slows movement from the colon to a standstill, but as toxins from bacterial die-off add up, explosive diarrhea can occur.

The Top Foods for Supporting Digestive Health

An optimal diet for restoring healthy gastrointestinal function should start with lots of lightly cooked vegetables. Steaming or low-heat sauté with minimal oil is best. Grilling and frying should be avoided until digestive health is restored.

Raw food should also be eliminated; all food should be cooked until GI health is restored. Smoothies are an exception because high torque food processors generally break down raw food enough so that it is well tolerated.

  • Vegetables like squash, spinach, green beans, asparagus, carrots, celery, sweet peas, and mushrooms are helpful for restoring the gut.
  • Cabbage is generally well tolerated, but other cruciferous vegetables (broccoli, cauliflower, brussel sprouts) are more difficult to digest and cause gas in many individuals; therefore avoided until digestive function is in better shape.
  • Vegetables from the onion and garlic family promote growth of favorable bacteria in the intestines.
  • Sweet potatoes are generally well tolerated, but regular potatoes should be minimized or avoided until normal function returns.
  • Avoid nightshade vegetables including tomatoes, potatoes, peppers, and eggplant.
  • Nuts should be avoided until digestive function returns to normal.
  • Temperate fruits (berries, apples, pears, peaches) can be enjoyed, but tropical fruits (oranges, pineapple, mangos) should be avoided.
  • Mung beans and lentils are the easiest beans to digest, but still contain lectins and should be avoided if the digestive tract is in bad shape.
  • Poultry (chicken, turkey) is the best meat option, but non-oily fish is also generally well tolerated. Tofu is acceptable in the absence of soy sensitivity.
  • Avoid dairy products with the exception of cultured yogurt and kefir.
  • Rice and gluten-free oats are the best tolerated grains.
  • Alcohol, tea, and coffee should be avoided until GI function is back to normal.

Additional Tips for Gut Health

  • Chew food thoroughly. Digestion starts in your mouth. Chewing is the only part of the digestive process over which we have voluntary control. Smaller and more frequent meals allow the stomach to return to normal size.
  • Drink apple cider vinegar before meals. Taking 1-2 tablespoons of apple cider vinegar (diluted in a 6oz. glass of water) with meals is a simple way to improve digestive function in the stomach. (Note: If stomach ulcers are a concern, digestive enzymes and vinegar should not be used unless instructed by a healthcare professional.)
  • Drink ginger tea. Consider this to be an essential part of your recovery. Ginger’s healing properties soothe an inflamed stomach and intestinal tract.
  • Take a probiotic to balance the bacteria ratio in your gut. Yogurt and other fermented food products are a source of good bacteria, but do not provide high enough counts to restore normal balance. When considering a probiotic, look for the lactobacillus and bifidobacteria strains.
  • Moderating stress and regularly practicing relaxation techniques is essential for allowing the gastrointestinal tract to perform its job. See our protocol for dealing with stress.

These guidelines should be followed until digestive function is back to normal. At that point, other foods can be carefully and gradually reintroduced. Attention should be given to food sensitivities when foods are reintroduced. Processed food products and fast food should stay off the list indefinitely.

Symptoms including abdominal pain, vomiting, severe diarrhea, rectal bleeding, or any other severe intestinal or abdominal complaints should be immediately brought to the attention of a qualified healthcare provider.

Learn more about Dr. Rawls’ Gut Health Protocol »

*Statements on this page have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. For medical concerns, please consult a qualified healthcare provider.