Disclaimer: As I have said in the past, I’m not a research blogger. I’m here to mix “data with soul” and give you useful info, but only in the context of my real, human experience. That is not to say that citation on my part and proper follow-up on your part are not important. Everything I wrote about in this blog was presented by Dr. Allison Siebecker at the SIBO Symposium during June 2015 and you can pay to have access to those presentations through the National College of Natural Medicine’s website.
There is just SO MUCH useful information that came out of this year’s SIBO Symposium! I find it hard to digest it all, let alone pick and choose what to write about and share with our audience here at Autoimmune Paleo. I decided for this Part 2 update to the series, to focus on the dietary approach to SIBO. I’ll be outlining what I learned from Dr. Allison Siebecker of the SIBO Center in Portland. She is a well-known rock star doctor of the SIBO world.
First, I want to start with the basics. Dr. Siebecker presented a really thorough (but concise) talk on the focus of all SIBO diets. I appreciated this talk very much, even though I already well understood everything she touched on, because I think in the SIBO community we can get a little confused around food, when really it is all about one particular issue, carbohydrate malabsorption.
Malabsorption is anytime nutrients are not properly absorbed in the small intestine. This could be micronutrients, like vitamins and minerals, or macronutrients like fat, protein, and carbohydrates. Malabsorption is caused by anything that prevents proper digestion and absorption, like certain drugs, enzyme deficiency, physical damage, or a disease such as Celiac. The signs of malabsorption range from deficiency diseases with vitamins and minerals to the classic symptoms of SIBO, bloating, constipation/diarrhea, pain, farting, burping, nausea, and/or acid reflux, with carbohydrate malabsorption.
If carbs are not absorbed in the small intestine and instead sit there or in the large intestine, it can feed bacteria and lead to an overgrowth. (It’s really important here, to emphasize that with SIBO the bacteria are not necessarily “bad.” There are just too many and they are in the wrong location. They belong in smaller numbers in the large intestine.) When these bacteria ferment (eat) they make gas as a by-product. In addition, the unabsorbed carbs sitting in the digestive tract cause water to be drawn into the intestine. This gas and water result in the well-known SIBO symptoms.
This starts a negative loop. The poor absorption of carbs feeds an overgrowth, the overgrowth does more damage to the small intestine, causing further malabsorption, which feeds even more bacteria. The damage caused by the bacteria ranges from inflammation to disruption of bile to actually eating our intestinal brush border. The brush border describes the millions of finger-like projections, villi, which line the walls of our small intestines. If SIBO is severe enough, these villi can become flattened, just like in Celiac disease. You could think of it needing to look like a plush, new carpet, but instead it looks like an old, worn, flat rug. In my own struggle with SIBO, one endoscopy showed this very damage. Since my gluten antibodies from Celiac disease indicated healing, my GI doctor felt the remaining villi damage was probably due to my then active SIBO and not Celiac. (You can see why SIBO is so common in Celiacs when you consider the villi damage contributing to this negative loop.) He explained to me that he saw that kind of damage in SIBO patients regularly.
Any source of carbohydrates, including glycosaminoglycan sugars (the sugars found in cartilage, skin, and bones, i.e. broth and gelatin for AIPers!), can be eaten by the bacteria and contribute to this very damaging feedback loop. The problem is that a diet completely free of carbs is imbalanced, impractical, and unhealthy. As Dr. Siebecker pointed out, it is both physically and emotionally unhealthy. For this reason, all dietary approaches to SIBO focus on reducing carbs, not totally eliminating them. The differences in these diets are simply the kinds of carbs that are singled out.
Okay, so now, we have a really clear understanding of the basic problem with eating and SIBO. It’s the carbs! And we know that there are several different diets that address the problem by targeting particular carbs. There is still an obvious question though, which diet to choose when you’re trying to manage SIBO symptoms. We are so lucky, because Dr. Siebecker gave us insight into how she and her colleagues at the SIBO Center view and use the various diets in helping patients.
They view the diets in a hierarchy based on their usefulness for the severity level of a patient’s case:
- For mild cases, they start with a simple Low-FODMAP diet. Mild cases are those that can tolerate some grains, starches, fiber, and sucrose. Low-FODMAP is also good for prevention following treatment, those who are underweight (and cannot afford further weight loss), and vegans or vegetarians. (The best info on the Low-FODMAP diet comes from Monash University in Australia. You can order their guide here.)
- For moderate cases, they use the Specific Carbohydrate Diet or SCD. Those with IBD, Celiac, and diarrheal diseases often land in this moderate group.
- For severe cases, they use the SIBO Specific Food Guide. This diet basically combines Low-FODMAP and SCD in order to arrive at the least fermentable foods and serving sizes. It is best for people who are so sick with SIBO, that they have developed a wide variety of intolerances and find little to no relief with other dietary approaches.
- For cases involving mood and brain disorders, they turn to the Gut and Psychology Syndrome diet or GAPS. This diet is useful for people who are also dealing with autism or bipolar disorder, for instance.
Dr. Siebecker stressed that determining the best dietary approach for you is a matter of individual experimentation to understand your symptom triggering foods and tailor your diet to avoid or reduce them. I cannot agree with this more both personally and as a coach. Triggers vary from person to person and depend on genetics, the type and amount of intestinal damage, and the types, amounts, and locations of the bacteria overgrown in an individual case.
Readers at Autoimmune Paleo may be asking where AIP fits in dealing with SIBO. My personal experience shows that combining AIP and the Low-FODMAP diet for a temporary period was the best way for me to reduce autoimmune symptoms and tackle SIBO at the same time. However, this is a really restrictive approach and requires lots of vigilance to avoid detrimental weight loss in those who are underweight and lots of experimentation to discover which High-FODMAP foods you personally may tolerate and at what serving sizes (this helps ensure that you get more variety and nutrient-density and that you keep the restrictions practical and physically/emotionally sustainable). Ideally, I think combining approaches is best done with the support of your doctor.
There it is, all the dietary approaches to reducing SIBO symptoms. (It’s a good idea to mention here, as I have in the past, that these diets are meant to help reduce symptoms, not treat SIBO. SIBO in adults cannot be treated with diet alone.) Have you found any of these approaches useful for you? Or do you see an idea here that seems like a good fit for you?