What is the best diet for SIBO?

Key Points

• SIBO is a complicated gut health issue that can be difficult to diagnose and treat.
• There are multiple different treatment options, both dietary and medical.
• It is important to have a care team you treat to help guide your SIBO treatment.

What is SIBO?

SIBO stands for small intestinal bacterial overgrowth. It is a form of gut dysbiosis characterized by excessive bacterial growth in the small intestine.

What are the symptoms of SIBO?

Those who suffer from SIBO typically experience excessive gas and bloating. Many also experience constipation, diarrhea, flatulence, as well as abdominal pain and cramps. Other SIBO symptoms can include having trouble digesting fat; some may find excess fat in their bowel movements, particularly when it comes to diarrhea.

Some SIBO patients may have concurrent low stomach acid, which can make symptoms even worse. Others may experience low gut motility, meaning it takes longer to digest food and can cause further bloating and discomfort.

How is SIBO diagnosed?

The gold standard method to test for SIBO is small bowel aspirate. However, the test is expensive and invasive to administer, so most doctors use glucose and lactulose breath tests. These tests can be ordered by a gastroenterologist. The breath tests, which measure methane and hydrogen, are not always accurate, with a high rate of false negatives and some false positives.

SIBO is still being studied. Its symptoms overlap with many other broad diagnoses, like IBS (irritable bowel syndrome). Combined with the complicated nature of SIBO testing, this makes diagnosing and treating the condition difficult.

SIBO treatment

The goal of SIBO treatment is to stop the “bad” bacteria in the small intestine from growing, reduce inflammation, and correct any possible nutritional deficiencies that may have resulted from the bacterial imbalance.

SIBO is generally treated with antibiotics. Rifaximin is generally considered the best antibiotic to act against SIBO due to its reduced toxicity. It also works well against other IBS-related symptoms.

However, the problematic gut bacteria can return after the initial course, making another form of treatment necessary. Some doctors will prescribe a second course of antibiotics while others will then turn to a dietary approach to try to eradicate the bacteria. There are a few different options for treating SIBO via diet.

Elemental diet

The elemental diet is one of the most prescribed dietary approaches for treating SIBO. It is a liquid diet administered through drink or feeding tube. Usually a powder mixed into water, the formulation is made of different nutrients, vitamins, and minerals. The powder can be purchased over the counter or acquired via prescription.

The diet is usually prescribed for 2-3 weeks. During this duration, this powdered drink is the only thing you can consume aside from water. Due to the extreme nature of the diet, the elemental diet should only be used under medical supervision and should only be made with a doctor-approved nutrient powder. The powder should not be homemade. The diet should not be followed at the same time as a course of antibiotics.

The drink is generally tasteless due to the lack of artificial flavoring. The idea behind the diet is that the pre-digested nutrients in the formula are easily absorbed and thus help to “starve” the bad bacteria in the small intestine.

This is, of course, an unsustainable way to live, and many people can’t stay on it long enough to see results. That said, one study found that 85% of participants who stayed on the diet for 15-21 days found that normalized their breath test with the elemental diet. However, more research is needed to confirm the efficacy of the diet.

FODMAP diet

A more sustainable and popular SIBO diet is the low FODMAP diet. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are types of carbohydrates that are easily fermented by gut bacteria and can worsen gas, bloating, and diarrhea.

Low FODMAP is a type of elimination diet where users remove all FODMAPs at once. After a period of time, you slowly reintroduce different FODMAP categories to see what types of carbs cause a reaction. You might be sensitive to some types of FODMAPs but not others.

Similarly to the elemental diet, the FODMAP diet is not a proven method, but anecdotally, some people have seen success with it. The key to following the FODMAP diet is to work with a registered dietitian who can educate you on the FODMAPs, help create a diet plan, oversee your dietary changes, monitor your symptoms, and create a reintroduction plan when the time is right.

Here are some high FODMAP foods to avoid during the diet:

• Fruits and vegetables like onion, garlic, apples, figs, watermelon, mangoes, mushrooms, and cauliflower
• Dairy products with lactose like milk, soft cheeses, and ice cream
• Grains and gluten like wheat, rye, and barley
• Sweeteners and sugar alternatives like high-fructose corn syrup, honey, and sugar alcohols like xylitol
• Some nuts such as pistachios and cashews
• Beans and lentils

There are plenty of FODMAP-free or low FODMAP foods that you can still enjoy on the diet, such as:

• Fruits and vegetables like strawberries, carrots, potatoes, zucchini, and avocado
• Protein sources like eggs, fish, chicken, and beef
• Some nuts and seeds like walnuts, almonds, and pumpkin seeds
• Lactose-free or dairy-free alternatives such as almond milk or lactose-free milk
• Gluten-free grains like quinoa and oats

Only carbohydrates fuel SIBO bacteria, so all fats and proteins are safe to consume without restriction during the low FODMAP diet.

Specific carbohydrate diet

The specific carbohydrate diet (SCD) is based on the idea that certain digestive disorders make it impossible to break down some carbohydrates, leaving behind undigested food particles in the digestive tract on which bacteria feed and grow.

SCD isn’t only prescribed for SIBO; people with Crohn’s disease, celiac disease, and other gut health and digestive disorders often follow the diet.

SCD eliminates these difficult-to-digest carbs and keeps carbs in general to a minimum to avoid feeding the bacterial overgrowth and reduce overall inflammation.

Here are some foods to avoid while following the specific carbohydrate diet:

• Grains and grain products like wheat, rice, quinoa, oats, and pasta
• Canned vegetables
• Dairy products high in lactose
• Sugars including standard sugar, maple syrup, corn syrup, fructose, and molasses

SCD is an even more restrictive diet than low FODMAP, making it difficult to follow and unsustainable for long periods of time. Due to this, it is infrequently prescribed as a treatment method. While there is some research supporting SCD as a Crohn’s treatment method, there is limited information about SCD as a SIBO treatment. However, your practitioner might consider it as an option if antibiotics and low FODMAP don’t work.

What is the best SIBO diet?

As you can tell, there is no singular “best” SIBO diet or treatment. The best SIBO treatment is the one that works for you and eliminates your symptoms. Some SIBO patients also find success with certain supplements and probiotics.

The most important thing when treating SIBO is having healthcare providers you trust. A gastroenterology clinic will be able to run all the tests you need and devise a treatment plan, but a registered dietitian nutritionist is the most qualified person to help you find the right diet for your symptoms.

You can find an RD who specializes in SIBO treatment with Fay Nutrition. All providers on Fay are covered by health insurance, making treatment much more accessible and even free.

All you have to do is input your insurance information and can then filter provider results by expertise. Within a few days, you’ll be connected to a trusted dietitian who can offer all the support you need to find some relief from your SIBO symptoms. Click here to get started.

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.