If you've been diagnosed with SIBO, or suspect you have it, the first question is usually what you can eat. The internet doesn't make it easy. There's the low FODMAP diet, the SIBO specific diet, the biphasic diet, the low fermentation diet, the elemental diet, and separate lists for methane, hydrogen and hydrogen sulfide types. Most of them contradict each other somewhere.
This guide explains what a SIBO diet can and can't do, which approach has the most evidence behind it, and gives you a practical food list to start from.
SIBO is diagnosed with a breath test and is usually treated with antibiotics prescribed by a doctor.1 Diet changes can ease symptoms, but on their own they aren't expected to clear the overgrowth. Don't self-diagnose or self-treat.
What Is SIBO?
In a healthy gut, the small intestine contains relatively few bacteria. Most live further down, in the large intestine. In small intestinal bacterial overgrowth (SIBO), there are more bacteria in the small intestine than expected, or bacteria that normally live in the colon have moved upward.
When you eat fermentable carbohydrates, those bacteria ferment them early, in the small intestine, producing gas. That's thought to explain the typical symptoms: bloating, abdominal discomfort, gas and diarrhea.5 SIBO is a debated diagnosis, and experts still disagree on exactly how to define it, which is one reason advice online varies so much.5
SIBO and IBS
SIBO and IBS share many symptoms, and studies suggest SIBO is more common in people with IBS than in people without it23, although the quality of that evidence is mixed. Possible shared causes include slower gut movement, low stomach acid and changes after a gut infection.4 If you have IBS symptoms that haven't improved with diet changes, it's reasonable to ask your doctor whether SIBO testing makes sense.
How Diet Helps With SIBO
The logic is simple. Bacteria in the small intestine feed on carbohydrates that you don't fully absorb, especially FODMAPs. Eat fewer of them, and there's less for the bacteria to ferment, so less gas and bloating.
That's why most SIBO diets restrict the same kinds of foods, even when they have different names. What a diet won't do is reduce the bacterial numbers back to normal. That's the job of medical treatment. Think of diet as a way to feel better while treatment works, and to keep symptoms calmer afterwards.
Which SIBO Diet Is Best?
There's limited trial evidence comparing diets specifically for SIBO.1
| Diet | What it is | Evidence |
|---|---|---|
| Low FODMAP | Temporary reduction of fermentable carbohydrates, then reintroduction | Strongest evidence in IBS; used for SIBO symptom relief |
| Low fermentation diet | Similar to low FODMAP, with extra limits on some fibers and starches | Practitioner-developed; little published trial data |
| SIBO specific diet | Combines low FODMAP with the specific carbohydrate diet | Practitioner-developed; not tested in trials |
| Biphasic diet | Two stages: a strict restriction phase, then a gradual expansion | Practitioner-developed; not tested in trials |
| Elemental diet | A liquid formula of pre-digested nutrients, replacing food for a set period | Small studies; used under medical supervision |
For most people, the low FODMAP diet is the most practical starting point. It's well defined, it's temporary by design, and it has a structured way to bring foods back. The stricter SIBO diets cut out many more foods without clear evidence that they work better, which makes them harder to follow and harder on nutrition.
SIBO Diet Food List
A low FODMAP-based SIBO diet looks like the standard elimination phase. Check any food you're unsure about in our FODMAP checker.
Foods to eat
- Proteins: chicken, turkey, beef, salmon and other fish, eggs, firm tofu, tempeh
- Grains and starches: rice, potatoes, oats, quinoa, polenta, rice noodles, traditional sourdough
- Vegetables: carrot, cucumber, zucchini in small amounts, green beans, spinach, bok choy, eggplant, green bell pepper
- Fruit: blueberries, kiwi, orange, pineapple, firm banana
- Dairy: lactose-free milk and yogurt, hard cheeses like cheddar and parmesan
- Fats and flavor: olive oil, garlic-infused oil, butter, herbs, spices, ginger, lemon, soy sauce
SIBO foods to avoid or limit
- Fructans: garlic, onion, leek (white part), wheat in larger amounts, rye bread
- GOS: beans, lentils, chickpeas, hummus
- Lactose: regular milk, ice cream, soft fresh cheeses
- Excess fructose: honey, agave, apples, mango, fruit juice
- Polyols: mushrooms, cauliflower in large amounts, stone fruits, and "sugar-free" products with sorbitol or xylitol
- Added fibers: inulin and chicory root in bars, yogurts and "gut health" products
Can you eat potatoes on a SIBO diet?
Yes. Potatoes are low FODMAP and a useful staple on a low FODMAP SIBO diet. Some stricter SIBO diets limit starchy foods, but there's no good evidence that potatoes need to be avoided. Rice is the same.
Methane, Hydrogen and Hydrogen Sulfide SIBO
Breath tests measure the gases bacteria produce. Many people now hear that they have "hydrogen SIBO" or "methane SIBO," and look for a diet to match.
- Hydrogen-predominant SIBO is more often linked with diarrhea.
- Methane is produced by microbes called archaea, not bacteria, so guidelines now use the term intestinal methanogen overgrowth (IMO).1 It's associated with constipation.6
- Hydrogen sulfide testing is newer and less established.
Lists of "methane SIBO foods to avoid" and "hydrogen SIBO foods to avoid" are popular, but there's no good evidence that each gas type needs a different diet. The same low-fermentation logic applies to all three. What does differ is how you manage the bowel pattern: with methane and constipation, enough fluid, regular movement and careful use of soluble fiber matter more. With hydrogen and diarrhea, regular smaller meals and limiting caffeine and very fatty meals may help.
The Elemental Diet for SIBO
An elemental diet replaces all food with a liquid formula made of nutrients in their simplest, pre-digested form. The idea is that they're absorbed early in the small intestine, leaving very little for bacteria to ferment. It's sometimes used when antibiotics haven't worked or can't be used.
It's demanding: the formula tastes unpleasant to many people, it replaces all meals for a period, and it can cause weight loss. Evidence comes from small studies. It should only be done with a doctor or dietitian supervising, and it isn't a first-line option for most people.
Preparing for a SIBO Breath Test
Before a breath test, clinics usually ask you to follow a restricted diet for a day and fast overnight, so that recent meals don't affect the result. Typical prep diets are very plain: baked or broiled chicken, fish or eggs, white rice, and water. You'll also be asked about recent antibiotics, laxatives and other medicines.6 Follow your clinic's instructions exactly, as they vary between test providers.
This prep diet is only for the test. It's far too limited to follow long term.
A Sample Day on a SIBO Diet
- Breakfast: oats made with lactose-free milk, blueberries and a little maple syrup
- Lunch: rice bowl with chicken, carrot, cucumber and a lemon and olive oil dressing
- Snack: lactose-free yogurt with kiwi
- Dinner: baked salmon with potatoes and green beans
For a full week, see our 7-day low FODMAP meal plan, and for more breakfast ideas, see low FODMAP breakfast ideas.
How Long Should You Follow a SIBO Diet?
Strict restriction is meant to be temporary. A common approach is to follow the low FODMAP elimination phase during and shortly after treatment, then bring foods back step by step through the reintroduction phase. Some practitioners suggest waiting until antibiotic treatment is finished before reintroducing, because the gut changes after treatment.
Staying on a very restricted diet for months can reduce the variety of your diet and the fiber your gut bacteria need. If symptoms keep coming back, talk to your doctor: SIBO can recur, and management should focus on finding and correcting underlying causes where possible.5
What About Probiotics?
Evidence for probiotics in SIBO is limited, and current guidelines don't recommend them as a treatment.1 Talk to your doctor before starting one. Read more in probiotics for IBS.
Common Questions
Is the low FODMAP diet good for SIBO?
It's the most practical way to reduce SIBO symptoms through diet, because it limits the carbohydrates bacteria ferment. It doesn't treat the overgrowth itself.
Can diet alone cure SIBO?
Not on current evidence. Treatment is usually antibiotics, guided by a doctor, along with addressing underlying causes.15
Is SIBO the same as IBS?
No, though the symptoms overlap and the two often occur together. A breath test is needed to diagnose SIBO. Our guide to IBS subtypes covers how IBS is classified.
The Stummy app can help you follow a low FODMAP SIBO diet day to day: scan foods to see their FODMAP content and track how meals affect your symptoms.
