There are a wide variety of dietary interventions that are used in the treatment strategy for gut dysfunction. In patients with gut dysfunction, a nutrition intervention can be undertaken as a part of the medical treatment plan. It is important to emphasize that these nutrition interventions are intended to be used for a limited period of time to assist with gut healing. A healthy, balanced, diet to manage a balanced inflammatory response should be the end goal of care.
The elimination diet, gluten-free diet, Specific Carbohydrate Diet, and FODMAP diet are a few examples of options that can be incorporated into a medical treatment nutrition plan. Ultimately, dietary interventions should focus on improving the diversity and quality of the gut microbiome by incorporating diverse plants with phytonutrients that help to cultivate the microbiome and promote important biochemical reactions via microbe-phytonutrient interaction.
Elimination Diet
The elimination diet is commonly the first approach in identifying food causes of digestive issues. Through trial and error, an elimination diet seeks to identify specific foods causing digestive issues and address whether it is an allergy or intolerance. Common foods eliminated include gluten, dairy, soy, refined sugar, peanuts, corn, alcohol, eggs, citrus, beef, shellfish and processed foods. The categories or specific foods are eliminated from the diet for two to three weeks. Then, foods that were eliminated are reintroduced individually to see if there are any responses to that specific food. An elimination diet helps to identify food allergies, reduce symptoms of irritable bowel syndrome (IBS), and heal the gut.
Common Elimination Foods |
Gluten |
Dairy |
Soy |
Refined sugar |
Peanuts |
Corn |
Alcohol |
Eggs |
Citrus |
Beef |
Shellfish |
Processed foods |
FODMAP Diet
“FODMAP” stands for “fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols,” describing the short-chain carbohydrates that are often poorly absorbed in the small intestine, thus leading to gut irritability. Understanding these categories helps individuals get a better understanding of why certain foods cause specific reactions in the gut.
Those with IBS may benefit from a diet lower in FODMAP carbohydrates, as it has been known to ease symptoms. Talking with a health care practitioner to further detail food choices is recommended. Low FODMAP foods include bean sprouts, beetroot, broccoli, carrots, eggplant, kale, lentils, and squashes, among many other vegetables. In the fruit category, low FODMAP options include, but are not limited to, blueberries, citrus, kiwi, passionfruit, pineapples, and strawberries. Therefore, the large misconception of eliminating fruits and vegetables, due to the high fiber content, in order to alleviate IBS symptoms is incorrect. It is simply about readjusting the types and quantity of produce that should be consumed. However, by default, natural gut microbiota will be adjusted due to the new food preferences, resolving common gut irritations.
Alternatively speaking, high FODMAP foods include, but are not limited to, artichokes, asparagus, cauliflower, fermented cabbage, mushrooms, soybeans, avocado, blackberries, dates, figs, mango, prunes, and watermelon.
FODMAP |
|
ALLOWED | NOT ALLOWED |
Unprocessed meats | Processed meats |
Eggs | |
Lactose-free dairy products (milk, cottage cheese) | Lactose |
Fats, oils | |
Nuts, seeds (in moderation) | |
Non-starchy vegetables (avocado, beets, bok choy, broccoli, chili peppers, carrots, celery, cucumber, eggplant, fennel, olive, mushrooms, spinach, squash) | Majority of starchy vegetables (excluding peas, potato, sweet potato, corn, taro, turnip, pumpkin) |
Legumes (sweet peas, peanuts) | Legumes (beans) |
Fruit (1/2 cup every 2 hours) (berries, citrus, banana, jackfruit, kiwi, grapes, pineapple, pawpaw) | |
Barley, oats, quinoa, rice, tapioca, buckwheat, arrowroot | Rye, wheat |
Tea, herbal teas | Alcohol (clear spirits in moderation) |
Sweeteners (maple syrup, stevia, saccharine, aspartame) | Caffeine (2 cups maximum daily) |
Gluten-Free Diet
Gluten is the protein found in wheat that serves to hold food together. In foods, ingredients that contain any combination of the following would contain gluten: wheat, durum, emmer, semolina, spelt, farina, farro, graham, rye, barley, triticale, and oats. There are many gluten-free options available today, including oats, and labeling has improved.
Celiac disease is an autoimmune disorder that damages the small intestine when gluten is consumed. The damage on the intestine’s villi prohibit nutrients from being properly absorbed. Thus, the only management for celiac disease is a gluten-free diet. The tTg-IgA blood test will screen for celiac disease antibodies, but it is possible that such responses will not indicate celiac disease but instead indicate a non-celiac wheat sensitivity. Following an elimination diet can help identify such triggers.
Non-gluten grains and other starches include quinoa, millet, amaranth, tapioca, rice, sorghum, gluten-free oats, arrowroot, yucca, chia, flax, beans, and nut flours. Depending on the severity of the disease, an individual may be sensitive to cross-contaminate in food preparation facilities. Such an individual may need to thoroughly read the ingredient section of the nutrition facts label as front of packaging claims may be misleading. Otherwise, all meats, fruits, vegetables, legumes, dairy, and oils follow a gluten-free diet.
Following a gluten-free diet is seen as a first step intervention in gut dysfunction for individuals with gluten sensitivity or celiac disease, as it is not as restrictive as elimination or low-FODMAP diets. If gut symptoms do not subside as a result of implementing a gluten-free diet, furthering the gluten-free diet to include elimination of casein is an additional option. This will eliminate all dairy from the diet, and the individual will focus on dairy alternatives such as coconut, hemp, nut, rice, or soy, adjusting for lactose intolerance.
Specific Carbohydrate Diet
The Specific Carbohydrate Diet (SCD) is extremely restrictive and limits carbohydrates. The carbohydrates that are allowed require minimal digestion, reducing inflammation related to digestive health issues. As a cautionary note, the SCD eliminates two food groups, dairy and grain, which can lead to nutritional deficiencies and affect energy levels. Supplements can help fill the gaps but cannot be used as a catch-all replacement for whole foods as the body will not digest or fulfill the same synergy as it would from whole foods. The SCD essentially leaves bacteria with nothing to feed on and encourages the cultured yogurts to replenish the good bacteria in the gut. While this protocol may be difficult to adhere to, it is also difficult to then pinpoint the exact GI distress cause by eliminating more than one food group at a time. Thus, following an elimination diet would better help pinpoint exact causes. Working with a nutritionist may help an individual thoroughly follow the SCD to achieve optimal results.
Specific Carbohydrate Diet (SCD) |
|
Allowed | Not Allowed |
Unprocessed meats | Processed meats |
30-day aged cheeses | Conventional or natural dairy, milk, cheeses |
Homemade 24-hour cultured yogurts | |
Avocado, olive, and coconut oil | |
Nuts and nut flours, natural peanut butter | Juices with additives |
Fresh, frozen, raw or cooked non-starchy vegetables (asparagus, broccoli, cauliflower, beets, carrots, cucumbers, eggplant, peppers, spinach, zucchini) | Grains Starchy, canned vegetables |
Dried navy beans, lentils, split peas, string beans | Sugars (lactose, sucrose, fructose, molasses, maltose) |
Fruits | High-caffeine food or beverages |
Pure fresh or dried spices | Legumes (chickpeas, bean sprouts, soybeans, mung beans) |
Honey | |
Broths |
The Role of Nutrition in GI Health
Nutrition fundamentals are key in identifying a food plan for individuals. With increased recognition of the importance of food in a functional and optimal approach, the body can better fight disease and improve quality of life.
A varied diet keeps diversity alive in the digestive tract. Vegetables, fruit, and whole grains will provide an abundance of benefits to gut health. Prebiotics, the plant fibers that go undigested through the GI tract, are known to help improve digestion and optimize immunity. Fibrous fruits and vegetables are considered a prebiotic, supporting good gut bacteria, and should be prevalent in the majority of meals throughout the day.
Reducing consumption of processed foods with added sugars will additionally help good gut bacteria flourish. Consuming monosaccharides (e.g. a piece of white bread), can derail microbial balance. This is partly because this food content takes little digestion and processing, hence not calling upon other microbes to action. That leaves the microbes inactive, eventually leading to inflammation as a result of immune system failure. This occurs as microbes travel and consume other pieces of microbiota or organ tissues as compared to a sprouted, or even whole, grain option.
The Role of Fiber in Gut Health
Fiber helps clean the GI tract, slow the rate of sugar absorption in the blood, aid intestinal movements, and, most commonly known, support regular elimination. Both soluble and insoluble fiber are pertinent to gut health. Soluble fiber is not well absorbed, thus slowing digestion. Typically found in oats, barley, nuts, and seeds, soluble fiber is known for protecting against heart disease. Insoluble fiber, found in vegetables and whole grains, adds bulk to processing waste and speeds up digestion. “Roughage” is a common term used to describe the structural parts of vegetables or grains in insoluble fiber. Many diet regimes are dependent upon what symptoms an individual is experiencing, and the amount and type of fiber can be adjusted or recommended. Generally speaking, a high-fiber diet increases the good bacteria in the gut through protection and restoration.
Diet | Microbiota affected | Effects |
High fat | Reduced:
Bacteroides Firmicutes |
Decreased microbial diversity,
increased bowel permeability, increased bile acid secretion |
Reduced carbohydrate | Reduced:
Bifidobacteria, Clostridium Bacteroides, Akkermansia |
Decreased SFCA production
and fiber-derived phenolic acids |
High protein | Increased:
Bacteroides, Lactobacillus Bifidobacteria |
Beneficial compounds from
proteolytic fermentation but toxic products from putrefaction |
FODMAP | Reduced:
Bifidobacteria Increased: Actinobacteria |
Improves IBS symptoms
in some patients |
The effects of specific diets on the microbiome (Table Reference: https://www.wholisticmatters.com/WholisticMatters/media/Wholistic-Matters/Monograph_Impact-of-Nutrition-on-the-Microbiome.pdf)