Ulcerative Colitis Dietary Therapy

Author, Frank W. Jackson MD
Updated June 2015

Introduction

Ulcerative Colitis (UC) is a disorder of the colon or large bowel. It usually begins as an inflammation of the colon down by the rectum and then spreads upward from there. Rectal bleeding is the hallmark of the disorder. With UC, the colon’s lining becomes inflamed, developing small open sores, called ulcers. These ulcers create mucous and pus. The inflammation, combined with the ulcers, cause abdominal pain and the need to frequently empty the colon.

In the past we physicians did not think there was anything specific in the diet that needed to be avoided. We prescribed a good nutritious diet with enough protein, calories, and vitamins and that was about it. Recently, however, there has been an explosion of information and research not just about the very cause of ulcerative colitis but also about the diet itself and how the foods we eat could favorably and unfavorably influence the disorder. The dietary treatment of UC, based on known recent and startling science and research, is now one of the most exciting new events in gastroenterology. It promises to have enormous benefits to almost everyone with this disorder. Before embarking further into the diet, it is useful to know briefly about 3 important areas. Here are 3 new proven key facts about Ulcerative Colitis.

Genes

Research has shown that up to 20% of the people suffering from UC have a close relative with the same disease. There is clearly a genetic makeup for those people who get UC. Up to 100 genes have been identified that may be involved and there are likely much more. Some of them are also present in those people who have or will get Crohn’s Disease. They are also present in other non-gastrointestinal disorders such as certain immune-related diseases like rheumatoid arthritis and multiple sclerosis. Research is moving very fast but as of this time, we know that genes are important. The gene is the 1st fact to remember.

Environment

By this, I want to cover a very broad area, but mostly it involves the diet. When people have active UC, we know it gets better when the bowel is put at complete rest. This means hardly anything except water by mouth. There is something in foods or liquids that we take by mouth that aggravates the colitis inflammatory process. When you remove these injurious factors, you get better. But we haven’t known for sure what it is that is causing the problem. Could it be a non-food item such as some environmental factor or chemical that is added to food? We don’t or, before now, didn’t know, but now we are beginning to get some pretty good ideas. The important point is that someone or multiple things that we take by mouth, most likely in the very foods we eat, are a problem. So, the 2nd fact to remember is environment or diet.

Gut Bacteria

Bacteria have a bad reputation because of advertising and the occasional bad bacteria that gets into the news. However, almost all bacteria are either benign or actually good for us. We simply have bacteria everywhere both inside and outside our body. For the most part, they protect us and usually provide very real health benefits.

The lower part of the intestine, the colon, contains an immense number of bacteria. These are likely key factors for the UC patient. As noted, the bacteria within our gut are usually our friends and give us many benefits such as making vitamins and a robust immune system. However, in the colitis person, there is a major shift from desirable to bad and unwanted bacteria. For reasons that are only now becoming clear, certain factors within the colon, including bacteria and even the smelly sulfide gases made there can cause inflammation. If there are no bacteria in the gut, there is no Ulcerative Colitis. So, the 3rd key fact to remember is bacteria.

Your Gut Bacteria Factory

To understand ulcerative colitis as we physicians now do, it is important to know the basics of what is happening within our own gut bacteria factory. The gut, especially the colon, is home to over 1000 species of bacteria and the total number of these little bugs are trillions upon trillions. For every cell in our body, there are at least 10 bacteria cells in the colon and the total number of genes of all these bacteria outnumber our own gene count by over 100 times. These beneficial bacteria have been part of us for as long as living things have been on earth.

As noted, we simply could not live without the benefits that these bacteria provide us. The most remarkable are that they give us a robust immune system that protects us our entire life. But here is where it gets troublesome for those with ulcerative colitis. If the bacteria factory is so beneficial, then why is it such a problem for those with the genetic makeup for UC? The answers to that question are slowly becoming known. Along with this knowledge is the fact that our treatments for UC have improved dramatically. But, just as important, so has our understanding of what happens within our gut with certain foods. We now know that some foods can and, indeed, do make a difference in the intestinal inflammation that is the hallmark of UC.

The Mucous Layer

The word mucous brings up a vision of a runny nose when you have a common cold. Not very pleasant. However, mucous is a very valuable and healthy substance to have in the body. Every membrane within our body has a mucous layer overlying it, including the inside of our nose. The excess mucous that comes from a nasal cold is simply the body’s method of protecting us and helping us get rid of the cold. A better term and one that we physicians and researchers use is biofilm. The mucous layer or biofilm is a dense layer of protein-like material that adheres to the inside lining of our intestinal tract. It is the first line of defense in the gut and prevents bacteria and other substances from moving through and attacking the wall of the gut itself. In addition, we have a vigorous and robust immune system in the wall of the colon itself. The mucous layer and these immune cells together are a strong defense mechanism except for people who get ulcerative colitis. Something happens to this mucous layer or biofilm. Under these conditions, bacteria and/or other substances are able to migrate through the mucous layer and cause inflammation to the underlying tissue. This is how colitis begins.

All people with ulcerative colitis make the smelly flatus gas, hydrogen sulfide. This gas is made by certain bacteria that live in the left side of the colon. This gas may be important and dangerous to the patient with ulcerative colitis. More on this later.

What Does Research Tell Us?

We, physicians, take pride in using evidence collected from research to guide us in treatment. Everyone wants proven facts whenever it comes to their treatment. We are slowly getting a handle on the very basic causes of ulcerative colitis. We know that a genetic makeup is required. We also know that something in what we eat and/or drink is really important. The answers are not all in yet, but we now know enough that we can give some pretty good answers to the dietary questions everyone with this disorder has.

A large medical study was published in the American Journal of Gastroenterology in 2011. The authors reviewed over 1000 published medical articles on this subject and found 19 that provided good enough information to reach important conclusions. Here is what they found.

There was an increased risk of getting the Ulcerative Colitis if a person ate:

  • A high protein and/or meat diet
  • A high saturated fat diet, including trans fats
  • A high vegetable polyunsaturated fat and especially omega 6 oil diet
  • A low fiber diet

a) Protein

Some of the reports looked at all animal protein that was consumed-meaning meat, poultry, fish and dairy products. Others evaluated just meat, meaning mostly beef and pork products. The consensus was that Ulcerative Colitis patients should not go overboard on animal protein, especially meat. The average daily amount of animal protein in an American diet is 75-100 grams. 50 grams is almost certainly enough. This is about the size of a deck of cards.

b) Fats

Saturated fat is found in well-marbled meat, bacon, all processed meat including sausage, but also in whole and even 1-2% fat-reduced milk. Butter, lard, chicken skin, coconut and palm oil are other sources of saturated fats. But the information on poly-unsaturated fats was what was most disturbing. These are the fats found in fish, most vegetable oils and nuts. They are the ones that have been shown to be so good for you in reducing cholesterol and perhaps heart disease. Nevertheless, in the colitis-prone individual, they seem to act differently. This was particularly true of the omega 6 vegetable oils. They make it more likely you will get UC. The bottom line seems to be that a reduction in most fats, including the omega 6 oils, may be a smart move.

c) Fiber

Here is where the payoff might be for the ulcerative colitis patient. It is the soluble plant fibers that are the major fertilizers and foods for the very best colon bacteria. It is these bacteria specifically that are so healthy for the gut wall. They produce lots of nutrients for the health of the colon cells. They acidify the inside of the colon, a very beneficial outcome, especially for the ulcerative colitis person. When they are exuberantly growing, these good bacteria prevent bad bacteria that none of us want in our lower bowel. Eating a wide variety of vegetable, fruit and whole grain foods every day does the trick.

Dietary Information

There is simply an enormous amount of good information on a low saturated fat and high fiber diet. These can be accessed online at usda.gov, eatright.org, amazon.com and every bookstore. Searching Google for high fiber diet and low-fat diets can be useful. In particular, look for non-commercial sources. The low saturated fat, high fiber diet recommended for coronary heart patients is exactly what seems to be beneficial for inflammatory bowel disease patients. The American Heart Association has cookbooks and recipes that can be ordered on their website, heart.org. It is exactly the type of diet for a person with inflammatory heart disease.

Inflammation

Inflammation is what ulcerative colitis is all about. The key fact is that bacteria within the gut, and/or other chemical factors such as the smelly colon gas, hydrogen sulfide, penetrate the protective mucous layer covering the inside of the gut. Science now knows a lot about inflammation in the body. For the colitis patient, they are worth knowing.

a) Colon wall

The typical Western-style, high saturated fat, high meat diet does 2 things that we know. First, it stimulates the production of excessive bile from the liver. In animals, this excess bile promotes the growth of certain bacteria in the colon which can cause an ulcerative colitis-like inflammation in susceptible animals. This is bad enough. But the 2nd major thing that these saturated fats do is to induce a change in the makeup of the bacteria in the gut itself. Again, this leads to mild but definite inflammation in the colon wall. Just as important, the cells that line the colon weaken and allow bacterial materials to leak between the cells and accumulate in the blood. This is known as a leaky gut. People on a Western style, high-fat diet have a leaky gut. This is not desirable.

b) Immune strength

The major part of your immune system comes from the colon wall. This starts on the day we are born when bacteria first start to grow in the infant’s intestine. Following a diet as outlined above enhances the strength of your immune system through your entire life. This, in turn, likely makes a positive difference in how your body responds to inflammation.

c) LPS (lipo-poly-saccharide)

This terrible sounding word refers to break down materials from the wall of the bacteria within the gut. When these substances slide through a leaky gut wall, as is present in UC, they then enter the blood stream. There they are called endotoxins or simply toxins. They induce inflammation throughout the body, in fat cells, in the lining of arteries (atherosclerosis), the liver and elsewhere. Nobody wants the toxins in their body, especially a colitis patient.

d) OMEGA 3, OMEGA 6, FISH OIL and VEGETABLE OILS

Understanding these oils can be plain confusing. Omega 3 oils are the really desirable ones. They are protective of the heart, are present in fish, especially fatty fish and in some nuts and vegetable oils such as canola oil. Omega 3 oils decrease inflammation in the body. Omega 6 oils, on the other hand, may be bad and not so desirable, even though they are of the polyunsaturated fat type. It is the ratio or the proportion of the omega 6 to the omega 3 oils in the product that appears to be important. For instance, olive oil has a ratio of 10:1, which is borderline desirable. However, olive oil has a great deal of the very desirable mono-unsaturated fats. Canola oil, on the other hand, has a ration of omega 6 to omega 3 of about 2:1, which is very good. Canola and olive oils are likely the healthiest cooking and vegetable oils for our bodies.

The bottom line for inflammation is to follow an ulcerative colitis diet as outlined above. This diet:

  • reduces the inflammation in the bowel wall
  • enhances the immune factors within it
  • reduces the inflammation that can occur within the body through a leaky gut and endotoxins
  • reduces the potentially damaging sulfide gases that arise in the colon

Animal Protein

Our bodies need amino acids in order to build the proteins we need to stay healthy. These amino acids come from proteins that we eat, either in animal meats or in plants such as fruits, whole grains, and vegetables. In either case, these proteins are broken down by our digestive system into amino acids, which are absorbed and then used to build our own proteins. Animal protein provides all the essential amino acids we need, whereas it is necessary to eat a variety of plant material to get the full complement of required amino acids. This is rather easily done. The bottom line is that our body doesn’t much care where the amino acids come from. They are all the same whether they come from animal or plant. However, there are other things in meat, especially the saturated fats that make a difference in what happens in the colon. Here a high animal meat diet leads to a bad balance of bacteria. This, in turn, induces inflammation and a leaky gut, which are not good for the colitis patient. Reducing the meat portion of a meal to about 50 grams provides the protein we need and also shifts the bacterial balance in a favorable way. 50 grams of meat is about the size of a deck of playing cards.

Fiber

Every vegetable, grain or fruit has fiber in it. It is what gives the plant its specific shape. Although there are many types of fiber, there are just 2 that are important for health, insoluble fiber and soluble fiber. Insoluble fiber means that the fiber does not dissolve in water and is not fermented by the colon’s bacteria. Rather, it retains water and, in so doing, helps to promote stool softness and regularity. Wheat in all its forms is mostly insoluble fiber. Soluble fiber, on the other hand, does dissolve in water. More important than this is the fact that the bacteria within the colon ferment it. It is a fuel for their own growth. The very best of the soluble fibers are called prebiotic fibers. A prebiotic fiber is used by the very best bacteria for their own nutrition and in so doing produce measurable health benefits for the body. Our Prebiotin Prebiotic Fiber is the most researched type of prebiotic fiber.

National authorities recommend the following daily intake of fiber.

  • Men: 30 grams
  • Women: 25 grams

These numbers will vary depending on sex, weight and body size. A varied mix of fruits, whole grains and vegetables will usually provide an adequate amount of both insoluble and soluble fibers.

A person with ulcerative colitis needs to increase fiber intake gradually so as to allow the gut to become tolerant to it. If this gradual process is followed, harmless excessive gas and bloating should not be a problem. Caffeinated beverages may overly stimulate the bowel.

Prebiotics

Prebiotic soluble plant fibers are the very best. They are present in many vegetables and fruits. These plant fibers promote the growth of the best beneficial colon bacteria. When these bacteria thrive, many positive health outcomes occur, including better immunity, increased calcium and magnesium absorption, a healthier bowel wall (no leaky gut), less inflammation, reduced toxins in the blood and many others. Oligofructose and inulin are the names of the 2 best-known prebiotics with the most research behind them. These prebiotic fibers are particularly rich in wheat, rye, leeks, asparagus, chicory, Jerusalem artichokes and many other root vegetables like yams, bananas, garlic, agave, and others. Our Prebiotin supplement, taken daily, can provide the assurance that you are getting enough prebiotic.

Fruit

It has long been known that fruits are an exceptionally healthy food for just about everyone. What has been recently found in Ulcerative Colitis patients is that fruits are specifically protective for them. Fruits have so many vitamins, minerals, antioxidants and so much fiber that there is virtually no limit to how much can be eaten. Fruit juice, on the other hand, may cause some problems. These are often high in plain glucose and fructose which may be troublesome for some. They usually have had all the beneficial fiber removed. Some colitis patients will note that their GI tract tends to act up with fruit juices. You simply have to test yourself.

Vegetables

Vegetables are the dietary backbone for the Ulcerative Colitis person. These are the foods that have so many of the beneficial fibers, including the very best prebiotics, inulin, and oligofructose. They provide bulk for bowel regularity and are the source of fuel for the beneficial bowel bacteria. It is these good bacteria that we want to see predominate within the gut. A high fat, high meat diet will always shift the bacterial balance in the opposite way, weakening the bowel wall, allowing a leaky gut to develop and ensuring that endotoxins or toxins are absorbed into the blood stream. A wide selection of vegetables should be eaten and prepared with condiments as desired. If oils are to be used in preparation, note that canola oil and olive oil are likely the healthiest and best, as they provide a very good ratio of the good omega 3 oil to the not-so-good omega 6 oils.

Hydrogen Sulfide, The Smelly Flatus Gas

Hydrogen sulfide (H2S) is a gas made by certain bacteria in the left side of the colon. This gas has been studied at many medical research centers throughout the world. Scientists and physicians at these institutions feel it is a very important and damaging gas for the ulcerative colitis person. It seems to be a critically important in initiating the damage in the lining of the colon.

Here is a very interesting fact. These H2S producing bacteria need a neutral environment to grow – no acid and no alkali. When a person, whether they are a UC patient or not, takes enough prebiotic in the form of food or a supplement, an acid rich environment occurs. H2S is not produced. The flatus does not have a foul smell. There is no less flatus but it is not noxious. Most importantly, do ulcerative colitis patients improve? Many people with ulcerative colitis report that they are better when their flatus or rectal gas no longer smells bad. The only side effect from prebiotic rich food or a supplement is bloating or excessive flatus. Simply reducing the dose corrects this minor problem. Our Prebiotin is the best prebiotic fiber supplement. Start with a low dose such as ½ teaspoon twice a day and increase it very gradually.

Vitamins

It is important to discuss vitamins with the physician. For the ulcerative colitis patient, the following points on vitamins are worth considering.

  • Multiple vitaminMany physicians feel that inflammatory bowel disease persons should take basic multiple vitamin preparations each day
  • Folic acidThis vitamin prevents birth defects so it is particularly important for the female who may become or actually is pregnant.
  • Vitamin D
    This vitamin is important for bone health. Vitamin D deficiency has been found to be much more common than previously thought. Some experts are recommending up to 800 IU each day. Check with your physician regarding vitamin D and calcium supplements as well.

Minerals

Eating a well-balanced diet with adequate whole grains and vegetables will usually provide all the minerals that the body needs. Additionally, most one-a-day multiple vitamin preparations will contain the minimum recommended doses of all minerals. However, there are 2 minerals that may warrant special attention for colitis patients.

  • Calcium
    In order to absorb and use calcium, you need adequate Vitamin D which you get from sunlight and foods such as milk or supplements. If you take a steroid medication such as prednisone, it is even more important as this drug can deplete the bones of calcium over the long term. A dietary supplement may be needed.
  • Iron
    Bleeding from the lining of the colon is what happens with ulcerative colitis. Because of this, iron deficiency may occur. Regular blood tests are usually needed to check for iron deficiency.

Prepared, Packaged and Bottled Foods

We know that there is a rising incidence of inflammatory bowel disease, especially ulcerative colitis, in the Western world and America. These increasing numbers parallel the change in our diet that has occurred over the past 100 years. There has been an increase in the saturated fats in the diet that is likely a significant factor. In addition, we now have a very wide variety of prepackaged, prepared and bottled foods that were not present in the past. These are truly manufactured foods. Food manufacturers add a wide range of chemical and other additives to their foods to enhance taste, smell and appearance, to improve mouth feel and, especially, to increase shelf life. Each of these substances has long ago been approved by the federal Food and Drug Administration (FDA) as GRAS (Generally Accepted As Safe). However, most of them were accepted long before much was known about how they might act in the gut of a colitis patient. Furthermore, we know virtually nothing about how they may interact one with the other. The best choice is to avoid these foods whenever possible. Most of them are present in the packaged foods in the central areas of large food stores. Shop the periphery of the store where fresh foods are sold. You also need to read labels. Be suspicious of foods that have dozens of ingredients and substances listed. In particular, if you don’t recognize the ingredient or word, simply do not buy the food. Look it up in a dictionary or the web. You need to be your own detective. Be suspicious of additives. They may be hurting you.

Emulsifiers

An emulsifier is a chemical that is added to prepared, packaged and bottled foods that we eat. It acts as an emulsion, for instance, emulsifying water and oil in a salad dressing so it is blended and does not need to be shaken. In addition to salad dressings, they are added to a great many of the common foods we all buy and eat, such as ice cream and sauces. They are used to give foods a better taste. They have no calories and so are substituted for many fats and are used in “low calorie” or “no calorie” foods, since many of them have the taste of a fat.

We know that in at least 2 instances that certain emulsifiers can cause a Crohn’s like inflammation in some animals. This has not been tested in animals that are prone to get ulcerative colitis type disorders. Nevertheless, it simply makes sense to avoid them whenever possible.

In an earlier section you will find information on the mucous layer in the intestine. It is also called the biofilm. It is a major defense barrier for the body as it keeps bacteria away from the bowel wall. Anything such as emulsifiers that potentially can damage this valuable mucous layer should be avoided. Here are just some of the emulsifiers found in many of the prepared foods we eat.

  • Xanthum gum
  • Gum Arabic
  • Guar gum
  • Polysorbates, such as 40 and 80
  • Lecithins from eggs
  • Hydroxypropyl methyl cellulose (HPMC), also call hydromellose
  • Carboxymethyl cellulose (CMC) -very commonly used in many products, even toothpaste.
  • Many other celluloses such as methyl cellulose which is stool bulking agent Citrucel

Polysorbate 80 and HPMC above have had published research where each of these 2 chemicals badly damaged the mucous layer in the animal’s colon and allowed a Crohn’s like illness to occur. It makes sense for colitis patients to avoid emulsifiers to the extent possible. Read labels. Do not buy products where you do not know what all the ingredient are. Assume one can be an emulsifier. You need to become educated on labels and food additives so you can protect yourself. Remember that the FDA has approved these ingredients long before we had any idea of how they might react in the intestine in a patient with inflammatory bowel disease. One final comment. Bread and other food manufacturers are now substituting emulsifiers for gluten, so if you see a food labeled gluten free, suspect that an emulsifier has been added in its place.

Detergents

Detergents, of course, are cleaning agents that dissolve fats and oils. They may do the same to the wonderful mucous membrane that lines the inside of our intestine. Once dissolved, the underlying cells of the intestine would be exposed to harmful bacteria. No one intentionally ingests detergents. However, they are everywhere around the house, especially the kitchen. They are used to clean dishes and glasses from which we eat food and drink liquids. Some very small dried amounts may remain on dishes that would be particularly harmful to a person who was genetically susceptible to colitis the next time the dried utensil is used? It is possible. It makes sense to use plenty of clean water to rinse the kitchen utensils thoroughly.

Probiotics

Probiotics are beneficial live bacteria taken by mouth that we hope will take up residence in the gut and thereby provide a benefit for the gut and the body. They are now being tested in many different medical disorders. The use of probiotics for any medical condition should be undertaken only with a physician that is knowledgeable in their use. As of 2012, there are several probiotics that have been found to be possibly helpful in the treatment of ulcerative colitis.

Probiotics have been shown to positively affect intestinal mucosa. They do so in several different ways:

  • They act as a barrier — By lining the intestinal tract near the brush border, they prevent bad bacteria from reaching the mucous membranes of the gut where, if they were able to access it, the bad bacteria would stimulate the mucosal immune system.
  • They stimulate mucus production — When there is a thicker mucus layer, it provides better protection from invasive bad bacteria.
  • They alter the mucus consistency — By altering the consistency of the mucus, they change the patterns by which bad bacteria can adhere to the lining.
  • They stimulate the secretion of protective immunoglobulins (Ig) — These Igs protect the gut from bad bacteria.
  • They make the mucosal immune system more anti-inflammatory — In particular, probiotics make dendritic cells so they become less responsive and less reactive to bad bacteria.

A Gastroenterologist’s Advice

I have seen and treated many patients with ulcerative colitis for many years. Way back, even before the colonoscopy was invented, we had a pretty good idea of what we were dealing with. It was basically an inflammation of the wall of the colon. We knew even then that there was a vague genetic link but really did not know very much beyond that. Now we know down to very specific genes that genetics is critical as to who gets colitis. But, we cannot change the genetic makeup of anyone, at least not yet. But, there have been 2 really huge findings in the last 20 years that have changed.

The first research success has been the discovery of the “biologics” as treatment. These biologic drugs are a whole new area of therapy for those people who have severe immunity-related disorders like inflammatory bowel disease, rheumatoid arthritis, and psoriasis. Remicade is the trade name of the one that has changed the lives for the better for some people with UC. Our researchers, drug companies, and our very physicians deserve a lot of credit for making this happen.

The second major change in our understanding of colitis is just cresting right now. It is 2 pronged. The first is the spectacular discoveries of how the bacteria within our very gut are of such a vital importance to our very health and well-being. Incredible new research tools have driven these findings. For the colitis patient, this new research has become critical because we now know that most UC patients have an abnormal and unwanted mix of bacteria in their gut. There are simply many more bad ones than good bacteria. This results in some bad things happening within the gut wall, none of which are desirable.

Along with this new research and understanding of these lifelong companions within our gut, has come new information that colitis patients themselves can change this bacterial mix in a positive way. Yes, what we now know is that UC is a complex disorder where you need a genetic background to get the disease. We also now know that the bacterial load in your gut is a bad mix. But by far the most important new finding is in the diet. We used to think that a high protein, meaning a high meat and saturated fat diet, was needed to assure the colitis patient of good nutrition. Now we know that was wrong. It is the fat in the diet, especially the saturated fat, and excessive meat as well that makes and allows the bacteria makeup to change in a deleterious way. It may be that simple. Reduce the daily saturated fat in the diet from 40% of the calories ingested to 20-25%. More difficult may be the finding that even vegetable fats, especially the omega 6 oils, in excessive doses may increase the risk of getting colitis. Finally, increasing the daily fiber in the diet is likely just as important. It is these fibers that fertilize the very best bacteria and that can push out the bad ones. Using daily prebiotic supplements such as Prebiotin can provide the assurance that enough is being ingested.

This diet could be a tough one to follow for many patients. It is different from the standard Western-style diet where meats of all sorts are the central part, along with the saturated fats and low fiber that usually accompany this diet. Nevertheless, it would be important for UC persons to know just how much they can contribute to their own well being by adjusting what goes in their gut. A 2-3 month strict trial on this diet will likely tell you. You perhaps will need a nutritionist to guide you. Do it. It is a lifelong deal. We cannot cure ulcerative colitis yet, but you, the patient, may have so much more that you can do to help yourself.

Medical References

1. High fat and low fiber diet increases risk of Crohn’s disease

Hou JK, Abraham B, El-Serag H. Dietary intake and risk of developing inflammatory bowel disease: a systematic review of the literature. Am J Gastroenterol, 2011 Apr;106(4):563-73.

2. How food interacts with the gut bacteria in Crohn’s Disease

Albenberg LG, Lewis JD, Wu GD. Food and the gut microbiota in inflammatory bowel diseases: a critical connection. Curr Opin Gastroenterol, 2012 Jul;28(4):314-20.

3. High animal protein intake increases the chance of inflammatory bowel disease

Jantchou P, Morois S, Clavel-Chapelon F et al. Animal protein intake and risk of inflammatory bowel disease: The E3N prospective study. Am J gastroenterol, 2010 Oct;105(10):2195-201, Epub 2010 May 11.

4. Prebiotic fiber provides health benefits for Crohn’s Disease patients

Gauarner F. Inulin and oligofructose: impact on intestinal diseases and disorders. Br J Nutr, 2005 Apr;93 Suppl 1:S61-5.

5. The smelly flatus gas hydrogen sulfide is linked to ulcerative colitis

Rowan FE, Docherty NG, Coffey JC, O’Connell PR. Sulphate-reducing bacteria and hydrogen sulphide in the aetiology of ulcerative colitis. Br J Surg, 2009 Feb;96(2):151-8.

6. A high fat diet causes toxins to enter the blood from gut bacteria

Pendyala S, Walker JM, Holt PR. A high-fat diet is associated with endotoxemia that originates from the gut. Gastroenterology, 2012 May; 142(5):1100-1101.e2. Epub 2012 Feb 8.

7. Emulsifier damage to the Crohn’s intestine-carboxy methyl cellulose

Swidsinski A, Ung V, Sydora BC, Loening-Baucke V et al. Bacterial overgrowth and inflammation of small intestine after carboxymethlcellulose ingestion in genetically susceptible mice. Inflamm Bowel Dis, 2009 Mar;15(3):359-64.

8. Emulsifier damage to Crohn’s intestine-polysorbate 80

Roberts CL, Keita AV, Duncan SH et al. translocation of Crohn’s disease Escherichia coli across M-cells: contrasting effects of soluble plant fibres and emulsifiers. Gut, 2010 Oct;59(10):1331-9. Epub 2010 Sep 2.

9. The genetic connection of Ulcerative Colitis

Crohn’s and Colitis. AbbVie Inc. Web. 10 June 2015.

10. The role probiotics play in Ulcerative Colitis

Fedorak RN. Probiotics in the Management of Ulcerative Colitis. Gastroenterology & Hepatology. 2010;6(11):688-690.

11. Description of Ulcerative Colitis

Crohn’s and Colitis of America. Web. 10 June 2015.