The Microbiome Connection Part 5: by Mark A. Pimentel
Low-fermentation eating originates from our knowledge of microbes. If you leave a teaspoon of olive oil on the counter, bacteria won’t grow on the oil. But if you mix a teaspoon of sugar (carbohydrate) into the oil, within a few days bacteria and fungi will ferment and spoil the oil. Carbohydrates are one of the main energy sources for bacteria, and when bacteria ferment carbohydrates, the sugar converts to gas that causes the bloating and abdominal distention of SIBO. The predominant driver of SIBO symptoms is sugar. Yes, we need sugar, but bacteria need sugar as well. If you can eliminate sugars that humans don’t digest and limit your intake of fiber (which is difficult to digest) you can limit your SIBO symptoms and decrease the chance of recurrence of SIBO. Low-fermentation eating has two essential rules: Restrict products that contain high levels of carbohydrates or ingredients in food that humans can’t digest, and therefore are digested by bacteria. Space meals four to five hours apart. At the top of the list of foods to avoid are non-absorbable sugars, such as sucralose, sorbitol, lactitol, xylitol, and mannitol. Humans can’t digest these artificial sweeteners, and therefore 100 percent of their calories are available for bacteria to digest. Non-digestible sugars will always cause bloating. For the same reason, you should avoid sugar-free gum, which often contains artificial sweeteners. Look for hidden inulin. Inulin is another food additive that may bother your gastrointestinal tract. Inulin is a type of fructan and prebiotic, a compound in food that can induce the growth or activity of microorganisms, such as bacteria. It’s extracted from chicory root fiber—a natural dietary fiber—and may also be found in smaller amounts in whole wheat and some vegetables and fruits, such as asparagus, garlic, and bananas. Inulin does, however, have some digestive benefits. It appears to help with constipation, and the fiber increases the amounts of beneficial Bifidobacteria and Lactobacilli bacteria in the gut. When you think of a non-digestible carbohydrate, think of fiber. Fiber is a carbohydrate that can’t be broken down by the body. It either passes through the digestive system unchanged (insoluble fiber), or is fermented by intestinal bacteria in the colon (soluble fiber). Fiber is found in intact plant foods, including fruits, vegetables, legumes, nuts, seeds, and whole grains. It can also be isolated and added to processed foods and fiber supplements (see inulin, above). In general, if you have IBS or SIBO, you’ll need to limit or eliminate high-fiber foods. When we advise less fiber in your diet, it doesn’t matter whether it’s soluble or insoluble. Less fiber means less gas production in the small intestine. You’ll need to eat fewer vegetables that have fiber, such as cruciferous vegetables, cabbage, sauerkraut, Brussels sprouts, and broccoli. We consider these foods as absolute “no-no’s” because of how quickly and potently they can worsen symptoms in SIBO and IBS. Some carbohydrates to avoid include black beans, pinto beans, kidney beans, and lupini beans. Chickpeas (the primary ingredient in hummus) can be extremely provocative. Lentils are an important source of protein among vegans, however, when SIBO is present, these legumes are among the worst provocateurs. We can’t emphasize enough the importance of keeping the gastrointestinal tract’s cleaning waves intact on a regular basis. These cleaning waves keep the small bowel clean, and they reduce bacteria therein. Notably, the housekeeping waves don’t occur until you are fasting. The feeding phase of digestion ends within one to four hours of eating, and then the housekeeping wave cycles begin. Based on this time frame, we recommend waiting four to five hours between each meal as part of low-fermentation eating. That will result in at least one set of housekeeping waves between each meal. This timing procedure will keep the small intestine clean of bacteria and residual foods, as well as residual enzymes that were secreted to move food through the gastrointestinal tract. If you have IBS or SIBO, we recommend you eat two or three distinct meals a day, four or five hours apart. This doesn’t mean you should be eating less, just less often. You don’t have to eliminate vegetables from your diet if you have IBS! In the carbohydrate realm of vegetables, it’s okay to eat vegetables like eggplant, tomato, and zucchini. We suggest that you eat what we call the “root and fruit” foods, as they don’t cause much trouble for IBS or SIBO patients. If you want a salad, instead of using lettuce, try a Greek or Shirazi salad with cucumber, tomato, and a small amount of onion. Root vegetables, such as potatoes, beets, and carrots, tend to be simpler carbohydrates. Sweet potato has more fiber and is on our optional list. Bell pepper is technically a fruit and is also okay to eat. You can mix a small amount of onion (as a flavoring ingredient) with ground beef for a burger. Small amounts of garlic also are acceptable. You can also use salt, pepper, and turmeric for seasoning. Some SIBO patients can tolerate small amounts of garlic. Garlic has many health benefits in addition to digestive benefits, as it’s an antioxidant and anti-inflammatory. Individualized attention to each person’s diet is important and the reason not to have tunnel vision with your diet for overall health. Some patients with IBS and SIBO eliminate garlic because they think they shouldn’t eat it at all because it’s banned from the low-FODMAP diet. Proteins, such as beef, chicken, or fish, are allowed in low fermentation eating, but if you eat in a restaurant they may be cooked in butter or other banned products, so be cautious and be sure. ****Please remember to work with a health care professional and only use these tips and tricks if you have IBS or SIBO**** Apart from the direct effect of sleep on gut motility, sleep is also very important in regulation of appetite and what we crave to eat. Sleep deprivation leads to decreased levels of leptin and an increased level of ghrelin hormones. The net effect is an increased appetite. For reasons that we don’t yet understand, sleep deprivation also increases endocannabinoids, which increase our craving for fat and sugar, similar to increased appetite with marijuana use (“the munchies”). This change in food consumption behavior has deleterious effects on SIBO and the gut microbiome. Some athletes drink protein shakes to bulk up, but most commercial protein powders contain sucralose or other unacceptable artificial sweeteners. Manufacturers use these non-absorbable sweeteners to make the drink more palatable, but you may feel bloated all day. Look for a protein shake with glucose or dextrose, not fructose, sucralose, or sorbitol, and nothing with prebiotics like inulin. We recommend whey protein isolate, which is derived from milk. If it’s pure whey protein, it shouldn’t have much lactose. For vegan athletes, we recommend pea protein. L-glutamine. This abundant amino acid, produced by the body and also found in food, may heal the lining of the bowel and help with IBS symptoms. A recent medium-sized randomized controlled trial found 5000 mg doses (about 2 teaspoons) of L-glutamine three times daily improved IBS symptoms and intestinal permeability, the so-called leaky gut. Larger trials are needed to confirm this data. L-glutamine is a safe supplement and an option for IBS treatment and potentially for leaky gut. Make sure you take a pure L-glutamine supplement with no other compounds. Remember: If you have IBS and you stop eating all food, your symptoms will improve dramatically. The bacteria wouldn’t have food, but neither would you! When your gut doesn’t work as hard, your symptoms dissipate, but a restricted diet is not a good long-term plan to control IBS. If you continue an overly restrictive diet for more than a few weeks, you may become deficient in macronutrients and micronutrients. The standard recommendation for more restricted diets is to reintroduce foods slowly within two to six weeks after starting the diet. There is no one answer to the question of which foods to reintroduce first. This depends on the restricted diet you were on and what you were eating. The most important thing is to regain balance in your diet, which may require the help of a dietitian or nutritionist. Exercise makes IBS better. Exercise increases blood flow to all organs, improves motility of the gut, and helps regulate bowel movements. Extreme exercise may be unfavorable to the gut due to a reduction of oxygen to the gut, but routine exercise is good for IBS patients. Studies of IBS patients show exercise assists in maintaining regular bowel habits. Exercise has the added benefit of releasing stress and, of course, provides many other health benefits.
