Microbiome Diet: The Naughty and Nice
I made my list and checked it twice! Here we’ll cover the foods you should focus on eating, as well as those that should be avoided or eliminated to support a healthy gut full of diverse microbiota. Although the holidays are not the most opportune time to take on such a diet, the new year is perfect for a fresh, healthy start! Will you join me in a new approach to diet and health?
The takeaway:
Focus on eating vegetables, fruit, high-quality meats and seafood, nuts, healthy fats, chickpeas, lentils, fermented veggies, and spices like turmeric, ginger and cinnamon
In Phase 1, avoid dairy, eggs, grains, potatoes/yams, sugar/sweeteners, soy, peanuts, alcohol, processed and packaged food, trans fats, artificial preservatives and additives
In Phase 2, add back in eggs, potatoes and yams, goat and sheep's milk products, kefir, legumes and gluten-free grains
The rest of the article covers more details of the Microbiome Diet.
I find it helpful to focus on the many healthy foods I do get to eat, rather than dwelling on the foods to avoid, so let’s briefly cover these first:
Vegetables, particularly those high in prebiotic fiber (asparagus, artichoke, garlic, jicama, leek, onion, radish, sunchoke/Jerusalem artichoke, tomato; and broccoli, broccolini, cauliflower, spinach, kale, Swiss chard, celery, carrot, cabbage, pepper, zucchini, eggplant, cucumber, etc.)
Starchy vegetables: spaghetti, butternut and acorn squashes; parsnip, beet
Fruits: apples, berries, oranges, grapefruit, mango, peaches, pears, lemons, limes
Meat: beef, chicken, lamb, fish, shellfish (ideally pasture-raised, grass-fed, wild caught)
Nuts: especially almonds, Brazil nuts, walnuts, macadamia, cashew; NO peanuts
Legumes: chickpeas and lentils
Fats (avocado, olive/coconut/sunflower/flaxseed oil, butter, ghee)
Fermented vegetables: sauerkraut, kimchi, etc.
Spices: ginger, turmeric, cinnamon
These “clean” foods are all packed with energy, fiber, vitamins, minerals and antioxidants to fuel your body, repair your intestine, and nourish your gut bacteria. Now let’s break down the structure of the diet and the foods to avoid during each phase. There are 3 phases to the Microbiome Diet.
Phase 1 is 3 weeks long, during which many foods are eliminated from the diet. Dr. Kellman encourages 100% compliance to the food list during this phase. Think of this period as a chance for your gut to take a break from the less healthy food choices you’ve made throughout your life.
Foods to avoid:
Processed or packaged foods
High fructose corn syrup
Trans/hydrogenated fats
Canola or cottonsweed oil
Artificial colors or preservatives
Sugars and sweeteners except Lakanto (monkfruit extract and erythitol)
Corn and corn starch
Iceberg lettuce
Alcohol
All soy: soy sauce, edamame, miso, tofu, tempeh, soy isolate protein EXCEPT soy lecithin
Processed or deli meats
Peanuts, peanut butter
Dried or canned fruit
Fruit juice
Dairy except butter and ghee
Gluten: all grains including rice and quinoa
Eggs
Potatoes, sweet potatoes, yams
Legumes: black/white/red/kidney/fava/string beans, EXCEPT chickpeas and lentils
Limit caffeinated beverages: coffee 1-2 8 oz cups, tea 3-5 8 oz cups daily
Phase 2 is 4 weeks long and some foods will be re-introduced. Dr. Kellman encourages 90% compliance to the diet during this phase. That means of the 35 meals you eat throughout the week (3 squares and 2 snacks daily), 3-4 can be indulgences.
Reintroduce these foods:
Eggs
Vegetables: sweet potatoes, yams
Goat or sheep milk cheese yogurt
Kefir of all types including cow’s milk
Unsweetened coconut milk
Gluten free grains: amaranth, buckwheat, millet, quinoa, oats (if made in gluten-free facility), rice (brown, wild, basmati; NO white rice)
Legumes: green beans, all beans (still no soy or peanuts)
Phase 3 is lifetime maintenance. Welcome to your new eating style! The foods in Phase 2 build the foundation of your diet, which means you will mostly be eating meat, seafood, poultry, veggies, fruits, nuts, fermented veggies, kefir, yogurt, healthy fats, eggs, legumes, gluten-free grains. Some foods should continue to be strictly avoided, some are re-introduced in moderation.
Foods to avoid always (limit consumption to 2-3 times per year):
Processed or packaged foods
High fructose corn syrup
Trans/hydrogenated fats
Canned fruit
Fruit juices
Soy: soy sauce, edamame, miso, tofu, tempeh, soy isolate protein except soy lecithin
Canola or cottonseed oils
Foods to add back in, consuming in moderation
Dairy
Dried fruit
Gluten, limit to twice weekly
Sugars and sweeteners (except Lakanto) limit to twice weekly
Here is your Microbiome Diet cheat sheet:
Dr. Kellman recommends following the diet with 70% compliance for the rest of your life. This means that of the 35 meals you eat throughout the week (3 squares and 2 snacks daily), approximately 10 can be your choice. If you think about it, that means 2 breakfasts, 2 lunches, 2 dinners and 4 snacks can essentially be whatever you want. Of course, it’s important to continue making smart food choices that support your overall health. For example, choosing to indulge in wholesome items like pasta, a special dessert, or a glass of wine rather than processed, fat-laden, nutrient-poor foods like French fries, packaged cookies or soda.
Not surprisingly, the Microbiome Diet recommends removing many foods from the “standard American diet”. Specifically highly processed foods that contain excess fat and carbs/sugar are avoided for a variety of reasons. Namely, these foods support unbalanced gut microbes and contributing to intestinal permeability, which can result in systemic inflammation [1]. Also, energy dense foods in the standard American diet generally lack nutritional quality—they offer calories without necessary fiber, vitamins, minerals, antioxidants, etc.
Some of the foods listed below are common allergens, others are known for having intolerances, and others simply detract from optimal health. Some foods, like eggs, dairy, legumes and grains, definitely have a place in a healthy diet. Dr. Kellman recommends avoiding them for Phases 1 and/or 2 because the proteins found in these foods can be reactive. Eggs, milk and wheat are common allergens, meaning they contain proteins that cause an immune reaction. Even if you are not allergic, if the gut wall is damaged, the proteins in these foods can escape into the bloodstream and cause an immune response and inflammation [2, 3].
Similarly, other grains and legumes contain lectins, which are proteins found in most plants. They are called agglutinins because their role is to help cells bind one another. Some lectins can also bind to bacteria and may help those bacteria adhere to the gut wall, thereby promoting the growth of certain bacteria. Other lectins actually block bacterial adherence and thus restrict growth of some bacteria in the gut [4]. Some studies suggest that wheat and other cereal grains contribute to chronic inflammation and autoimmune disease [5]. Gliadin, a component of gluten, increases intestinal permeability allowing food particles to pass through the gut wall. This can stimulate the immune system and result in inflammation.
Often, the reactivity of lectins in the gut is cited as a reason to avoid grains such as wheat and legumes including various beans, soy and peanuts [6, 7]. Some preparation methods such as cooking, sprouting, and fermenting can inactivate certain lectins. However, Dr. Kellman recommends avoiding these foods initially to give the gut a break from these potentially reactive components.
Because they do offer fiber which supports the growth of a diverse microbiota, chickpeas and lentils are included throughout the entire diet. And, as noted above, most legumes and grains (except soy, peanuts and wheat) are added back in later in the diet.
Many people struggle with the idea of not eating dairy, beans, grains and especially eggs. I get it; my breakfasts for the past couple years have been eggs or oatmeal. I was weary of feeling hungry after only eating fruit and a few nuts or a smoothie for breakfast, especially because while I had gestational diabetes I strictly avoided fruit for breakfast because it can spike blood sugar.
Despite this, I quickly grew to love a fruit-centric breakfast and continue to choose it regularly. It is surprisingly filling (due to the high fiber and water content), and I think you will feel satisfied after only eating fruit, especially as your gut heals, beneficial microbes flourish and your cravings subside. And an added bonus, my daughter now eats tons more fruit and loves smoothies!
I didn’t cover all the “non-compliant” foods, but basically the idea of the first 3 weeks is to get back to basics: allow the gut to heal, rebalance the microbiota, and load up whole, nutritious foods. I will cover the remaining foods in later post, but until then, focus on the healthy, energizing, healing foods that nurture you and your microbiota.
References
Bischoff, S.C., et al., Intestinal permeability--a new target for disease prevention and therapy. BMC Gastroenterol, 2014. 14: p. 189.
Drisko, J., et al., Treating irritable bowel syndrome with a food elimination diet followed by food challenge and probiotics. J Am Coll Nutr, 2006. 25(6): p. 514-22.
Guo, H., et al., The value of eliminating foods according to food-specific immunoglobulin G antibodies in irritable bowel syndrome with diarrhoea. J Int Med Res, 2012. 40(1): p. 204-10.
Pusztai, A., et al., Kidney bean lectin-induced Escherichia coli overgrowth in the small intestine is blocked by GNA, a mannose-specific lectin. J Appl Bacteriol, 1993. 75(4): p. 360-8.
de Punder, K. and L. Pruimboom, The dietary intake of wheat and other cereal grains and their role in inflammation. Nutrients, 2013. 5(3): p. 771-87.
Freed, D.L., Do dietary lectins cause disease? BMJ, 1999. 318(7190): p. 1023-4.
Vojdani, A., Lectins, agglutinins, and their roles in autoimmune reactivities. Altern Ther Health Med, 2015. 21 Suppl 1: p. 46-51.