What is the best diet for SIBO?

Key Points

• SIBO can be tricky to diagnose, but several proven treatment options exist.
• Low FODMAP, elemental diet, and specific carbohydrate diet (SCD) are the three main dietary approaches.
• Working with a registered dietitian who specializes in SIBO can help you find the right approach for your symptoms.

If you're dealing with bloating, gas, and digestive issues that won't quit, you might be wondering: do I have SIBO.

Small intestinal bacterial overgrowth (SIBO) can make eating stressful, with every meal feeling like a gamble as to whether it will upset your stomach. And when you start looking for solutions, the sheer number of diet options can feel overwhelming.

Don’t worry. While SIBO can be difficult to resolve, you have options. Let's break down the main SIBO diets so you can figure out which one might work best for you.

What is SIBO?

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

What are the symptoms of SIBO?

If you have SIBO, you'll typically experience excessive gas and bloating. Many also experience constipation, diarrhea, flatulence, as well as abdominal pain and cramps. Other symptoms can include having trouble digesting fat – some people find excess fat in their bowel movements, particularly when experiencing 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 can be 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

Finding the right treatment can feel overwhelming. There are several options, and what works varies from person to person.

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.

💡 Tip: If you have SIBO, you're also at higher risk for B12 deficiency. Focus on B12-rich foods like fish, beef, and nutritional yeast – or ask your doctor about supplementing.

Elemental diet

The elemental diet is one of the most prescribed dietary approaches for treating SIBO. It's a liquid diet administered through a 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 time, 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. 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 normalized their breath test – that's about 8 out of 10 people who saw their SIBO completely clear. However, more research is needed to confirm the efficacy of the diet.

💡 Tip: Some people find the powder more palatable when mixed with ice-cold water and sipped slowly throughout the day rather than chugging it all at once.

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 different 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 you remove all FODMAPs at once, then slowly reintroduce different FODMAP categories to see what types of carbs cause a reaction. You might find that you’re 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 working 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.

💡 Tip: Keep a food journal to track which low-FODMAP foods work best for you. You might find that some foods on the safe list still cause symptoms, or you might find that you can tolerate certain higher-FODMAP foods but not others.

A registered dietitian can help you create a personalized FODMAP elimination plan and guide you through the reintroduction phase. Many insurance plans cover these sessions, making professional support more accessible than you might think.

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. This leaves behind undigested food particles in your digestive tract, which the bacteria feed on, enabling them to grow and cause further distress.

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. The goal is 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's infrequently prescribed as a treatment method. While there's some research supporting SCD as a Crohn's treatment method, there's 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.

💡 Tip: If SCD feels too restrictive, talk to your dietitian about trying low FODMAP first—it's more sustainable for most people and has similar benefits.

What is the best SIBO diet?

So with all these different options, which diet should you choose?

As you can tell, there's 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.

💡 Tip: Consider asking your dietitian about specific SIBO-friendly probiotics that might support your treatment. Not all probiotics are created equal, and some can actually make SIBO worse.

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.

SIBO is undoubtedly a complicated and confusing issue to resolve. That's why working with an RD who specializes in SIBO makes such a difference – they can help you navigate the choices and find what actually works for your body.

You can find an RD who specializes in SIBO treatment with Fay. All providers on Fay are covered by health insurance, making treatment much more accessible and even free, giving you the care you need at a cost you can afford.

Get started now by inputting your insurance information and filtering by SIBO. Soon, you’ll be connected to a qualified dietitian who can help get you on the right treatment path.

Frequently Asked Questions

How long does it take for the SIBO diet to work?

The timeline varies depending on which approach you're using.

For the elemental diet, you'll typically see results within 2-3 weeks, which is the entire duration of the protocol. Studies show that about 80-85% of people normalize their breath tests after 14-21 days on the elemental diet.

For the low FODMAP diet, expect a longer timeline. The elimination phase usually lasts 4-8 weeks, followed by a careful reintroduction phase that can take several more weeks. You might notice symptom relief within the first few weeks, but identifying all your specific triggers takes time.

The specific carbohydrate diet also requires patience; most people follow it for several months before seeing significant improvement.

It's important to work with a dietitian to monitor your progress and adjust your approach if you're not seeing results within the expected timeframe.

Can I cure SIBO with diet alone?

Honestly? Probably not.

Antibiotics are the first-line treatment for SIBO, and they're the most effective at clearing the bacterial overgrowth. Diet is typically used alongside antibiotics or after an antibiotic course to prevent the bacteria from returning.

That said, some people do find success managing their symptoms with diet alone, especially if they can't tolerate antibiotics or if the antibiotics haven't worked.

The most important thing is addressing the root cause of your SIBO. If there's an underlying issue – like low stomach acid, slow gut motility, or a structural problem – the bacteria will likely return unless you address that too.

A gastroenterologist and registered dietitian working together can help you develop a comprehensive treatment plan that combines medication, diet, and addressing root causes for long-term success.

What foods should I avoid with SIBO?

This depends on which diet approach you're following and what triggers your specific symptoms.

For the low FODMAP diet, you'll avoid high-FODMAP foods like:

• Onions, garlic, apples, watermelon, and mushrooms
• Dairy products with lactose
• Wheat, rye, and barley
• Beans, lentils, and cashews
• Honey and high-fructose corn syrup

For the specific carbohydrate diet, you'll avoid:

• All grains (including rice, quinoa, and oats)
• Canned vegetables
• Most sugars and sweeteners
• High-lactose dairy

For the elemental diet, you'll avoid all solid food, consuming only the prescribed liquid formula.

Here's the thing: triggers vary from person to person. What bothers you might not bother someone else with SIBO. That's why working with a registered dietitian is so valuable – they can help you identify your personal triggers and create a plan that works for your life.

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.