What is SIBO, how to know if you have it, and what diet is best? Plus, why antibiotics and antimicrobials alone don’t work….and what you should be doing instead, according to a registered dietitian and gut health expert.
Note from Dena: I’m excited to share this guest post on such an important topic. It was co-written by Marla Ramos, Dietetic Intern, as part of a research partnership between Back To The Book Nutrition and post-graduate nutrition students from the University of Houston.
Bloating. Gas. Abdominal pain. Belching. Diarrhea. Constipation.
We all suffer from these from time to time, but if you’re one of many people who are experiencing one or more of these symptoms on a weekly – or even daily – basis, you may have SIBO. In fact, if you’ve been diagnosed with Irritable Bowel Syndrome (IBS), you’re almost guaranteed to have SIBO (Source).
What is SIBO?
SIBO stands for Small Intestinal Bacterial Overgrowth, and has traditionally been thought to occur when either too many or the wrong type of bacteria multiply in the small intestine. I believe this overemphasis on the overgrowths in SIBO is why the traditional approach of repetitive rounds of antibiotics (or herbal antimicrobials) fail.
A more accurate understanding of SIBO is that there are imbalances in the small intestine, and in the gut overall. In fact, many studies show that what what causes SIBO symptoms is not the of bacterial overgrowth. Rather, not having enough bacterial variety in the small intestines is the problem. This is critical for understanding how to fix SIBO.
3 MAIN TYPES OF SIBO
- Methane-Predominant SIBO – Caused by bacteria that produce primarily methane, giving rise to constipation, which is why this form is sometimes called SIBO-C.
- Hydrogren-Predominant SIBO – Caused by bacteria that produce hydrogen, which is sometimes associated with diarrhea or loose stools. Hence, this form is sometimes referred to as SIBO-D, though some with this form of SIBO do not have loose stools.
- Hydrogen Sulfide SIBO – a newer classification of SIBO where bacteria produce hyddrogen sulfide gas. This type of SIBO is often marked by very foul, sulfur-smelling gas and diarrhea, sometimes made worse by sulfur containing foods, supplements, and medications.
What Causes SIBO?
The root causes of SIBO are still being understood, but it seems as though risk factors are similar to those for other gut disorders.
Contributors to SIBO
- Poor immune function
- Insufficient stomach acid, digestive enzymes, and/or bile
- Eating too quickly, not chewing well
- Standard American Diet (processed foods, low fiber, pesticides, chemicals)
- Dysmotility (slowed passage of digested food through the small intestines). (Source)
This may not sound like a big deal. But it can wreak havoc on the GI system and, if it isn’t treated, can lead to other health complications.
Health Complications Related to SIBO
- Heartburn and Reflux
- Anemia (due to iron and vitamin B12 deficiency)
- Weight loss (due to malabsorption)
- Irritable Bowel Syndrome (78% have SIBO)
- Rosacea (46% have SIBO)
- Fibromyalgia (100% have SIBO)
- Obesity (41% have SIBO)
- Leaky Gut (since the overgrowth of bacteria can wear away the gut lining)
- Food Sensitivities caused by leaky gut
- Inflammatory Bowel Disease (Crohn’s, Ulcerative Colitis) (8-12 X higher SIBO rates)
- Nutrient deficiencies (due to poor absorption in the small intestine)
- Osteoporosis (due to vitamin D deficiency)
- Diabetes (SIBO 25% and 30% more likely in Type 1 and Type 2, respectively vs controls)
- Neuropathy (due to vitamin E deficiency)
- Night blindness (due to vitamin A deficiency)
How Do I Know if I Have SIBO?
If you have any of the following symptoms and are not getting better with treatment or diet changes, you may have SIBO.
- Bloating, especially after eating – this often accumulates throughout the day, then resolves overnight
- Excessive Gas
- Abdominal Pain
- Excessive Belching
How to Test for SIBO
Currently, there is no perfect test for SIBO. Scientists are hard at work exploring new methods of testing, but these are the most common currently:
- 3-hour Lactulose breath test – at-home or in-office test, must be ordered by a doctor, dietitian, or other licensed practitioner. This has been heavily questioned by both conventional and holistic providers due to recent studies showing high false positive and negative rates. Many providers have abandoned it.
- Glucose breath test – at-home or in-office test, can be ordered by patient, but likely also has too many false positive/negatives to rely on it entirely.
- Hydrogen-Sulfide breath test – The “Trio Smart” SIBO breath test to identify Hydrogen Sulfide SIBO as well as Methane-Predominant and Hydrogen-Predominant SIBO in a single test. Has not been as extensively studied so time will tell whether there are similar concerns to other breath testing methods.
- GI MAP or other comprehensive stool testing using PCR (DNA) technology – This at home stool test cannot diagnose SIBO, but does identify overgrowths of common SIBO organisms as well as other pathogens, overgrowths, yeasts/fungi, and markers for leaky gut and glucose intolerance. This is my first preference because of the breadth of information it gives us about the overall gut environment, all of which need to be addressed for lasting SIBO results.
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I Have SIBO – How Do I Treat It?
The most important thing to keep in mind is that SIBO isn’t just a single infection needing a single treatment. So just taking antibiotics and going back to living your life will not work in most cases.
SIBO is an imbalance that likely developed over months or years due to multiple factors. And, if you want lasting relief, you’ll need to devote several months to addressing all of the contributors in a holistic way using a combination of the diet, supplements, lifestyle, and medications outlined below.
Conventional Medical Treatments for SIBO:
Antibiotics, two in particular, have shown to have great results in the treatment of SIBO.
- Rifaximin (brand name Xifaxan) for Hydrogen-predominant SIBO (Source)
- Rifaximin + Neomycin combination for Methane-predominant SIBO (Source)
- Treatment for Hydrogen Sulfide SIBO hasn’t been well established, but a combination of antibiotics, bismuth, and other medications have been used.
Prokinetic agents (such as Metoclopramide) are often given alongside antibiotics to help move things through the gut more quickly and reduce risk of feeding the bacteria.
Natural Therapies for SIBO:
If you prefer not to take prescription antibiotics, a recent study showed herbal therapies may work just as well, and usually with fewer side effects.
- Allicin (Garlic)
- Olive leaf
- Cat’s Claw
- Atrantil (blend of several botanicals) – Works best on methane-predominant SIBO.
Prebiotics and Probiotics for SIBO:
Recent studies have shown that prebiotics and probiotics may be an effective alternative to antibiotics in treating SIBO or, at the very least, can improve outcomes when added to antibiotics. (Source) Download your free Ultimate Guide to Probiotic Supplements here!
Neurological Therapy for SIBO:
Functional neurologist Dr. Datis Kharrazian suggests that many individuals with SIBO have a problem with their brain-to-gut connection, which allows the overgrowth to occur in the first place. He maintains that many of his patients with SIBO benefit from simple, at home therapies (such as aggressive gargling, inducing a gag reflex, etc.) that can be done several times daily to re-train the brain-to-gut connection. These therapies essentially repair the motility problem for which conventional doctors might prescribe prokinetics.
Here is an excellent interview with Dr. Kharrazian in which he discusses a number of gut-brain issues. The entire hour-long interview is fascinating but, if you want to skip straight to the at home therapies and discussion of SIBO, they’re around minute 12 and 18, respectively.
Popular SIBO Diets (short term use only):
There are several different diets recommended for the treatment of SIBO. Each of these uses similar principles and show success relieving symptoms. But, such restrictive diets can be difficult to maintain, unlikely to permanently resolve SIBO, and – as mentioned above – may do more harm than good in the long run.
It’s best to work with a registered dietitian to help determine whether a particular “SIBO diet” is best for you, and to help you with a personalized plan for gradual reintroductions as your symptoms improve. (Sources: 1, 2)
- Low FODMAPs Diet
- Specific Carbohydrate Diet (SCD)
- Gut and Psychology Syndrome Diet (GAPS)
- SIBO Specific Diet
- Elemental Diet (a fully digested liquid diet intended for short term use)
- Cedars-Sinai Diet (Less restrictive and developed by Dr. Pimentel, the pioneer of the SIBO-IBS connection)
If you’ve already been through one or more rounds of the restrictive SIBO diets and antibiotics/antimicrobials above, you may need to focus more on improving digestive juices and motility, while gradually expanding your diet to include more variety again. This can be a slow and frustrating process, and having a professional to guide you can help immensely.
Will My SIBO Come Back?
Unfortunately, our understanding of SIBO and how to effectively treat it is still evolving. Even with effective treatment, SIBO has a recurrence rate of 44%. (Source) Again, I believe this dismal statistic has a lot to do with the fact that killing overgrowths has been the almost exclusive approach to SIBO until more recently.
To reduce the risk of recurrence, it’s important to use antibiotics and antimicrobials judiciously, to address the more global gut dysfunctions listed above, and to eat a plant rich diet that feeds a diverse microbiome.
Steps to Reduce Risk of SIBO Recurrence
- Eat a nutrient dense diet with a broad variety of plant foods for fiber, polyphenols.
- Include fermented foods often.
- Minimize intake of inflammatory foods like processed vegetable oils, refined foods, and added sugars.
- Eat enough protein, ideally from bioavailable sources like meats, poultry, fish, and eggs.
- Manage stress.
- Get adequate sleep.
- Exercise regularly, but not excessively.
- Avoid unnecessary antibiotics, PPIs, NSAIDs, and other medications that disrupt gut flora.
- Consider regular probiotic use.
Get Help with SIBO Today!
Want a holistic approach to overcome SIBO? I’d love to help! Schedule a free, 10 minute Discovery call and let’s talk details!
About the co-author: Marla Ramos is a Dietetic Intern, with a B.S. in Human Nutrition and Foods from the University of Houston. She has a particular interest in gut health due to her own personal experience with Crohn’s Disease.
Disclaimer: Information on this site is intended only for informational purposes and is not a substitute for medical advice. Always consult with a trusted healthcare provider before implementing significant dietary change. Read additional disclaimer info here.