The Best Diet for SIBO + Why Diet Alone Won’t Fix It

What is SIBO, how do you get tested, and how do you treat it? What’s the best diet for SIBO? Get answers to all these and more, plus how to book an appointment for one on one help from a registered dietitian.

Note from Dena: I’m excited to share this guest post on such an important topic. It was written by Marla Ramos, Dietetic Intern, as part of a new 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 it can occur when either too many or the wrong type of bacteria multiply in the small intestine. In fact, an official medical diagnosis of SIBO defines it as an infection where 1,000 times more bacteria than normal are present in the small intestine. (Source)

3 MAIN TYPES OF SIBO

1. Methane-Predominant SIBO – Caused by bacteria that produce primarily methane, giving rise to constipation, which is why this form is sometimes called SIBO-C.
2. 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.
3. 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

• Stress
• Inflammation
• Poor immune function
• Insufficient stomach acid
• Eating too quickly, not chewing well
• Standard American Diet (high in refined carbs and processed foods)
• Disruption in the bacterial balance of the gut
• Dysmotility (slowed passage of digested food through the small intestines). (Source)

These factors can lead to an overgrowth of bacteria in the small intestine in one of three ways (or sometimes a mix of these):

1. Small intestinal bacteria “feed” on poorly digested food matter that doesn’t move through the small intestine as quickly as it should, allowing the bacteria to proliferate.
2. A skewing of the microbial balance in the gut removes some of the “checks and balances,” allowing certain species to overgrow.
3. Bacteria from the large intestine travel back up to the small intestine and proliferate. Sometimes this is linked to a faulty ileocecal valve (IC), which acts like a door between the small intestine and large intestine. If it remains open more often than it should, this bacterial migration can occur.  

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
• Nutrient deficiencies (due to poor absorption in the small intestine)
• Osteoporosis (due to vitamin D deficiency)
• 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, consider testing for SIBO.

• Bloating, especially after eating – this often accumulates throughout the day, then resolves overnight
• Excessive Gas
• Abdominal Pain
• Excessive Belching
• Diarrhea
• Constipation
• Fatigue
• Depression
• Rash
• Eczema

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
• Glucose breath test – at-home or in-office test, can be ordered by patient, but less accurate than lactulose test
• Hydrogen-Sulfide breath test – The new “Trio Smart” SIBO breath test to identify Hydrogen Sulfide SIBO as well as Methane-Predominant and Hydrogen-Predominant SIBO in a single test. 
• GI MAP or other comprehensive stool testing using PCR (DNA) technology – This at home stool test is not diagnostic for 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. A skilled practitioner can infer whether SIBO is present based on symptoms + GI MAP results. 

(Note from Dena: GI MAP is my preferred test since it gives a much more comprehensive look at what’s going on in the gut – in my experience, SIBO usually doesn’t exist in isolation, so it’s very helpful to find out what else is going on in the gut to get you a more comprehensive plan that reduces risk for SIBO relapse!)

Get tested for SIBO – Schedule a free call to learn more!

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I Have SIBO – How Do I Treat It?

There are a few different approaches to addressing SIBO, and the latest research indicates that a combination of medical + nutritional therapies are most effective.

But here’s where it gets interesting.

According to Dr. Mark Pimentel, MD, Director of the Gut Motility Program at Cedar-Sinai Medical Center and leading expert in SIBO, well-fed bacteria are easier to kill with antibiotics (both conventional and natural) than those that have first undergone a period of diet changes.

Because of this, some experts recommended basic diet changes (reducing sugars, refined grains, and dairy) rather than overly restrictive diets that were previously recommended for SIBO. The entire process of medical + nutritional therapy can take 6-12 months. (Source) It’s important to consult with qualified providers about which of the following medical treatments and dietary approaches might be best for you.

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)

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)
• Berberine
• Oregano
• Olive leaf
• Neem
• Cinnamon
• Cat’s Claw
• Atrantil (blend of several botanicals) – Works best on methane-predominant SIBO.

(Sources: 1, 2, 3)

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.

Best Diets for SIBO:  

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 make personalized adjustments along the way for the best results. (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)

More info on each of these SIBO diets can be found here.

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)

To reduce the risk of recurrence, it’s important to also treat the underlying causes listed above, such as inflammation, poor immune function, insufficient stomach acid, and dysmotility.

Steps to Reduce Risk of SIBO Recurrence

1. Eat a nutrient dense, SIBO-preventive diet, such Pimentel’s SIBO Diet or another diet listed above.
2. Minimize intake of inflammatory foods like processed vegetable oils, refined foods, and added sugars.
3. Manage stress.
4. Get adequate sleep.
5. Exercise regularly, but not excessively.
6. Avoid unnecessary antibiotics, PPIs, and other medications that disrupt gut flora.
7. Consider regular probiotic use.

Get Help with SIBO Today!

Want help with  your SIBO, IBS, or other gut health issues? Schedule a free, 10 minute Discovery call and let’s talk details!

Schedule your free, 10 minute call now!

About the 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.