A SIBO diet is a short-term eating plan for small intestinal bacterial overgrowth that cuts back on fermentable carbohydrates, usually through a low-FODMAP or low-fermentation approach, to ease the bloating, gas and diarrhea that bacteria in the small intestine cause. It can calm symptoms, but the American Gastroenterological Association (AGA) states that diet alone is not able to cure SIBO[1]. Antimicrobials remain the established management[2].
This guide compares the main SIBO diets, gives a food list, a sample day and the rules for timing, and explains how methane and hydrogen types change the plan. For causes, symptoms and testing, see our page on what SIBO is.
Get medical help promptly if you have blood or black, tarry stool, a high fever, severe belly pain, frequent vomiting or signs of dehydration. These need a clinician, not a diet change[3]. Unplanned weight loss can also be a sign that SIBO is affecting how you absorb nutrients[1].
Can diet alone clear SIBO?
Usually not. The ACG guideline says the data on diet for SIBO are "principally extensions of the data from IBS," and it rated the low-FODMAP evidence in irritable bowel syndrome as very low quality[4]. A 2022 review concluded that the benefit of an IBS diet in SIBO is "largely hypothetical"[5].
The limited head-to-head data point the same way:
- Low FODMAP vs. rifaximin: in a 2025 randomized trial of 100 adults with IBS, 17% had SIBO. SIBO was eradicated in 63.6% of that small subgroup on rifaximin and 50.0% on the low-FODMAP diet[6].
- Diet as an add-on: in a 179-person SIBO trial, both arms received antibiotics plus a low-FODMAP diet, which reflects how diet is usually used in practice[7].
- The exception: an exclusive elemental (liquid formula) diet has normalized breath tests in uncontrolled studies, covered below[8].
Relapse is also common. In one study of 80 adults, SIBO returned in 12.6% at 3 months and 43.7% at 9 months after antibiotics[4]. The AGA says diet may help control symptoms and possibly reduce relapses[1]. Medication choices belong to your clinician; our SIBO treatment protocol covers the full plan.
Do herbs or supplements help alongside diet?
None has replaced antibiotics in trials. In the 179-person trial, adding herbal antimicrobials, probiotics and prebiotics to antibiotics and a low-FODMAP diet did not significantly change breath-gas levels, although clinical remission was higher, especially in methane cases[7]. Diet, fiber and meal timing, covered below, work alongside medical care rather than replacing it[1]. Herbal options are covered in our SIBO and IMO protocol.
How does a SIBO diet work?
It removes the food the excess bacteria ferment. When bacteria in the small intestine meet fermentable carbohydrates, they produce gas, and that gas drives most symptoms[9]. Less fermentable fuel means less gas and less fluid pulled into the gut[9].
The main targets are the FODMAP groups[9][1]:
- Oligosaccharides: fructans and galactans in wheat, onion, garlic and beans.
- Disaccharides: lactose in milk, yogurt and ice cream.
- Monosaccharides: excess fructose in honey, apples, mangoes and cherries.
- Polyols: sorbitol, mannitol and xylitol in pears, mushrooms and sugar-free gum.
In SIBO, bacteria can ferment fructose and lactose before your gut absorbs them, so a "lactose intolerance" may really be fermentation by overgrowth[9]. That is also why the North American consensus says SIBO should be ruled out before breath tests for lactose or fructose malabsorption[10].
What is the recommended diet for people with SIBO?
For most people, a dietitian-guided low-FODMAP or low-fermentation diet during and after treatment. The elemental diet has the strongest breath-test data but is hard to follow. Other named diets have little or no SIBO-specific evidence.
| Diet | What it removes | Typical length | SIBO evidence | Main drawbacks |
|---|---|---|---|---|
| Low-FODMAP | Fructans, galactans, lactose, excess fructose, polyols | 4 to 6 weeks, then reintroduction[1] | Mostly extrapolated from IBS; a 98-person survey reported less bloating[11] | Fewer than half found it easy; may lower Bifidobacterium[5] |
| Low-fermentation | Dairy, high-fructose foods, beans, cauliflower, sugar alcohols; adds meal spacing | Short term, then personalized[9] | Extrapolated from IBS; not rigorously studied[9] | Usually low in fiber[4] |
| Elemental (liquid formula only) | All solid food | 2 weeks, sometimes 3[8] | 80% to 85% normalized breath tests in one uncontrolled study of 93 people[8] | Up to 40% cannot tolerate oral formulas; cost and social limits[12] |
| Specific carbohydrate (SCD), biphasic, low-sulfur | Varies by plan | Varies | No SIBO trials found in our October 2026 PubMed search | Highly restrictive; untested |
Low-FODMAP diet for SIBO
This is the most widely used plan. It runs in three phases: restriction, reintroduction of one FODMAP group at a time, and a personalized long-term diet[9]. The AGA recommends starting reintroduction after about 4 to 6 weeks, ideally with a gastrointestinal dietitian[1]. Stanford Health Care describes the same four-to-six-week elimination phase[13].
In a 2026 survey of 98 people with IBS, SIBO or IMO who had tried it, bloating fell the most, and benefit did not depend on the diagnosis[11]. Only 43.9% completed the diet, and people who completed both phases were about 3.5 times more likely to improve[11]. The survey used an unvalidated questionnaire, so treat these numbers as a signal, not proof.
Low-fermentation diet
This is a simpler version that removes the common gas producers: dairy, high-fructose foods, beans, cauliflower, Brussels sprouts and sugar alcohols[9]. The ACG and AGA add cutting high-fiber foods, inulin and other prebiotic supplements, alcohol, and sweeteners such as sucralose[4][1].
If low-FODMAP starches such as rice, cereal or potatoes still bother you, the AGA notes that a low-carb diet for SIBO may help more than a low-FODMAP one[1].
Elemental diet
An elemental diet replaces all food with a formula of pre-digested nutrients, including the daily requirement of vitamins and minerals, that is absorbed high in the small intestine, leaving no fermentable carbohydrate or fiber for bacteria further down[9]. In a 2004 study, 80% of 93 people with IBS and an abnormal breath test had a normal test after 14 days, and 85% after 21 days[8]. There was no control group.
A 2025 open-label trial of a better-tasting formula in 30 adults with SIBO or IMO found that all finished the 2 weeks and 73% normalized their breath tests[14]. One study author was from the formula company. Use an elemental diet only under medical supervision; a review cautions against it for people with restrictive eating disorders[12].
Specific carbohydrate, biphasic and other named diets
We found no published trial testing the specific carbohydrate diet in SIBO when we searched PubMed in October 2026, and we found no trial data for biphasic, low-sulfur, keto or carnivore plans in SIBO. They restrict more than a low-FODMAP diet without evidence that they work better.
SIBO diet food list: what to eat and what to limit
Fill your plate from the left column during the restriction phase, and test the right column back in later. This list follows a hospital low-FODMAP guide; serving sizes matter, because symptoms build with the total fermentable load[15][9].
| Food group | Lower-fermentation choices | Limit during restriction |
|---|---|---|
| Protein | Chicken, fish, steak, turkey, eggs, firm tofu | Canned, baked or refried beans; hummus |
| Grains | Rice, quinoa, gluten-free bread and pasta, grits, polenta, 1/4 cup dry oatmeal | Wheat or rye bread, wheat crackers and cereals, high-fiber bars |
| Vegetables | Leafy greens, tomatoes, cucumber, carrots, bell peppers, white potatoes, eggplant, 1/2 cup green beans | Broccoli, cauliflower, Brussels sprouts, mushrooms, sweet corn, asparagus, celery, onion, garlic |
| Fruit | 1/2 small banana, 1 clementine, 1/2 cup berries, grapes, pineapple, cantaloupe, kiwi | Apples, pears, cherries, peaches, mangoes, watermelon, dried fruit, fruit juice |
| Dairy | Lactose-free milk and yogurt, aged cheeses (cheddar, Swiss, Parmesan), almond milk | Cow's milk, regular yogurt, ice cream, cottage cheese, soft cheese |
| Fats, nuts, flavor | Olive oil, 2 tablespoons of most nuts or seeds (walnuts, pumpkin seeds), scallion greens, herbs, ginger, mustard | Pistachios, cashews, ketchup, commercial dressings |
| Sweeteners and drinks | Small amounts of sugar or pure maple syrup, black coffee, green or peppermint tea | Honey, agave, high-fructose corn syrup, sorbitol, xylitol, sugar-free candy |
Source for foods and portions: University Hospitals[15].
Two points that lists often miss:
- Gluten and dairy are not FODMAPs. Wheat is limited for its fructans and milk for its lactose, so a low-FODMAP diet is neither gluten-free nor dairy-free[1].
- Fat can matter too. Some people with SIBO find high-fat foods worsen their symptoms[1].
What's the worst thing to eat with SIBO?
There is no single worst food, but the most consistent culprits are concentrated fermentable carbohydrates. The ACG and AGA single out sugar alcohols, sucralose, inulin and other prebiotic supplements, and alcohol, alongside high-FODMAP foods such as onion, garlic, beans and apples[4][1]. Large portions matter more than single bites, because symptoms track the total fermentable load[9].
What can you eat while being treated for SIBO?
Eat from the lower-fermentation list, space your meals, and keep the plan time-limited. Diet runs alongside antibiotics in trials rather than replacing them[7]. In the 2026 survey, people who had taken antibiotics before the diet were about seven times more likely to respond to it[11].
Space your meals. The migrating motor complex is a wave of contractions that sweeps the stomach and small bowel during fasting, and eating interrupts it[16]. Its absence has been linked to SIBO[16]. The AGA suggests waiting at least 3 hours between meals or snacks and not eating close to bedtime[1].
Ask about fiber, not just less of it. In one trial of 77 people with SIBO, adding 5 g a day of partially hydrolyzed guar gum to rifaximin raised the eradication rate from 62.1% to 85.0%[17]. That is a single trial, so check with your clinician before adding a supplement.
A sample low-FODMAP day
Built from the University Hospitals sample meal plan[15]:
- Breakfast: omelet with baby spinach and cheddar, with 2 slices of gluten-free toast.
- Lunch: homemade chicken and rice soup with carrots, red bell pepper, spinach and tomatoes; 1/2 cup grapes; rice crackers.
- Dinner: baked fish, brown rice with olive oil, roasted carrots and 1/2 cup strawberries.
Leave 3 or more hours between meals instead of snacking[1].
Methane, hydrogen and hydrogen sulfide: does the type change the diet?
The core diet is the same, but methane-dominant cases need extra attention to fiber and constipation.
What is intestinal methanogen overgrowth?
A methane level of 10 ppm or more on a breath test points to methane-producing archaea, which the ACG now calls intestinal methanogen overgrowth (IMO) rather than SIBO[4]. The main producer is Methanobrevibacter smithii[4].
How each type changes the plan
- Methane (IMO): a 2025 meta-analysis of 1,293 people with IMO found more constipation (47% vs. 38%) and less diarrhea than in controls[18]. A review stresses enough fiber from low-fermentation produce, such as citrus, berries, leafy greens, root vegetables and zucchini, to avoid worsening constipation[9].
- Hydrogen: the standard low-FODMAP or low-fermentation approach applies[9].
- Hydrogen sulfide: a flat breath-test pattern has been suggested to reflect hydrogen sulfide producers, which standard machines cannot measure[10]. We found no diet trials for this type.
In the elemental-diet trial, M. smithii abundance fell and tracked with lower methane levels[14].
How long should you follow a SIBO diet?
Keep strict restriction to about 4 to 6 weeks, then reintroduce foods[1][9]. Staying on it longer carries costs for your gut microbiome and your nutrition.
FODMAPs act as prebiotics that feed Akkermansia muciniphila, Bifidobacterium and Faecalibacterium prausnitzii and support short-chain fatty acid production[9]. A 2022 review found that 4 to 9 weeks of low-FODMAP eating lowered Bifidobacterium in several IBS trials[5]. None of those studies included people with SIBO[5].
Reintroduction helps identify your personal triggers and lowers the risk of nutrient gaps[1]. Long-standing SIBO can cause weight loss and low vitamin B12 and vitamins A, D and E, so ask your clinician whether to check these[1][19].
What to eat before a SIBO breath test
The test-prep diet is different from the treatment diet: it is one day long. The North American consensus advises avoiding fermentable foods such as complex carbohydrates the day before and fasting for 8 to 12 hours[10]. It also notes that meat and rice do not appear to affect the result, and that dairy should be avoided the evening before[10]. Follow the instructions from your testing lab if they differ.
How is small intestinal bacterial overgrowth diagnosed?
Usually with a glucose or lactulose breath test. A hydrogen rise of 20 ppm or more within 90 minutes counts as positive for SIBO, and methane of 10 ppm or more as methane-positive[10]. Breath tests can give false positive and false negative results, so a result is one input to your clinician's decision[20]. Our SIBO page covers testing in more detail.
When to see a doctor
See a clinician before starting a restrictive diet if:
- you have not been diagnosed, because SIBO symptoms overlap with IBS and other conditions[4];
- you are losing weight without trying, or have been told your vitamin B12 is low[1][19];
- your food list keeps shrinking, or eating has become stressful[9];
- symptoms return after treatment, since recurrence is common[4].
Get same-day care for blood in your stool, black stool, high fever, severe belly pain or dehydration[3].
If you have ongoing bloating without a SIBO diagnosis, our bloating page covers the other common causes.
This article is for general educational purposes and is not medical advice. A SIBO diet can ease symptoms but does not replace diagnosis or treatment, and the food lists here follow published low-FODMAP guidance rather than a plan tailored to you. Talk to a qualified healthcare professional or registered dietitian before starting a restrictive or elemental diet, adding supplements or changing medication, particularly if you are pregnant, immunocompromised, taking prescription medication, or managing a diagnosed condition.
Frequently Asked Questions
Are eggs OK for SIBO?
Usually, yes. The SIBO diet works by limiting fermentable carbohydrates that bacteria turn into gas, and eggs are not on the high-FODMAP lists we read. The University Hospitals low-FODMAP meal plan includes omelets and hard-boiled eggs. Some people with SIBO find high-fat meals worsen symptoms, so a fried, fatty breakfast may feel different from a boiled egg. Track your own response.
Is quinoa safe for SIBO?
Quinoa is on the allowed list of the low-FODMAP diet, which is the plan most often used for SIBO symptoms. The University Hospitals low-FODMAP guide lists cooked quinoa, quinoa pasta and quinoa flakes as allowed grains. The AGA notes that some people with SIBO react to low-FODMAP starches such as rice, cereal and potatoes too, so if grains still cause bloating, a lower-carbohydrate approach may suit you better.
Are blueberries good for SIBO?
Blueberries are one of the lower-FODMAP fruits. The University Hospitals guide allows a half-cup serving of blueberries, strawberries or raspberries, while apples, pears, cherries, mangoes and watermelon are on the avoid list. Portion matters: symptoms come from the total fermentable load of a meal, so a small bowl may be fine where a large one is not.
Can you eat gluten on a SIBO diet?
Gluten itself is not the issue. The AGA states that gluten and dairy are not FODMAPs and that a low-FODMAP diet is not gluten-free. Wheat, rye and barley are limited because they contain fructans, a fermentable carbohydrate. The University Hospitals guide lists gluten-free breads and pasta as allowed. If you have celiac disease, that is a separate, strict gluten-free diet.
Can I eat cottage cheese with SIBO?
Regular cottage cheese contains lactose, and the University Hospitals low-FODMAP guide lists it as a food to avoid during elimination. Lactose-free cottage cheese and aged cheeses such as cheddar, Swiss and Parmesan are on its allowed list. In SIBO, excess bacteria can ferment lactose before it is absorbed, so lactose-free versions are the usual swap.
How can I tell if I have SIBO or IBS?
You cannot tell from symptoms alone, because they overlap: bloating, gas, belly pain and diarrhea are common to both, and 14% to 40% of people with IBS may also have SIBO. Diagnosis usually relies on a glucose or lactulose breath test ordered by a clinician, although these tests can give false results. Our pages on SIBO and IBS explain the differences in more detail.
Is there a Stanford FODMAP diet PDF available?
Stanford Health Care publishes a low-FODMAP diet resource. When we opened its PDF link in October 2026, it led to a web page that explains the FODMAP groups and a two-phase plan: eliminate high-FODMAP foods for four to six weeks, then slowly add them back. It did not list portion sizes. The University Hospitals low-FODMAP guide we used for the food table on this page does list portions.
Does SIBO show up on bloodwork?
Not directly. SIBO is usually tested with a breath test. Blood tests can show its effects in some people: the AGA notes elevated folate and, less commonly, vitamin B12 deficiency, and the ACG guideline lists vitamin B12, vitamin D and iron deficiencies in severe cases. Normal bloodwork does not rule SIBO in or out.
References
- American Gastroenterological Association. Small intestinal bacterial overgrowth (SIBO): Managing with diet. AGA GI Patient Center. 2024. Available at: https://patient.gastro.org/small-intestinal-bacterial-overgrowth-sibo-managing-with-diet/ ↩
- Rej A, Potter MDE, Talley NJ, Shah A, Holtmann G, Sanders DS. Evidence-Based and Emerging Diet Recommendations for Small Bowel Disorders. American Journal of Gastroenterology. 2022;117(6):958-964. doi:10.14309/ajg.0000000000001764 ↩
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Diarrhea. NIDDK, National Institutes of Health. 2024. Available at: https://www.niddk.nih.gov/health-information/digestive-diseases/diarrhea/symptoms-causes ↩
- Pimentel M, Saad RJ, Long MD, Rao SSC. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. American Journal of Gastroenterology. 2020;115(2):165-178. doi:10.14309/ajg.0000000000000501 ↩
- Wielgosz-Grochowska JP, Domanski N, Drywień ME. Efficacy of an Irritable Bowel Syndrome Diet in the Treatment of Small Intestinal Bacterial Overgrowth: A Narrative Review. Nutrients. 2022;14(16):3382. doi:10.3390/nu14163382 ↩
- Chuah KH, Loo QY, Loh AJC, et al.. Clinical Trial: Rifaximin Versus Low FODMAP Diet in Irritable Bowel Syndrome. Alimentary Pharmacology & Therapeutics. 2025;63(2):210-221. doi:10.1111/apt.70420 ↩
- Redondo-Cuevas L, Belloch L, Martín-Carbonell V, et al.. Do Herbal Supplements and Probiotics Complement Antibiotics and Diet in the Management of SIBO? A Randomized Clinical Trial. Nutrients. 2024;16(7):1083. doi:10.3390/nu16071083 ↩
- Pimentel M, Constantino T, Kong Y, Bajwa M, Rezaei A, Park S. A 14-Day Elemental Diet Is Highly Effective in Normalizing the Lactulose Breath Test. Digestive Diseases and Sciences. 2004;49(1):73-77. doi:10.1023/b:ddas.0000011605.43979.e1 ↩
- Velasco-Aburto S, Llama-Palacios A, Sánchez MC, Ciudad MJ, Collado L. Nutritional Approach to Small Intestinal Bacterial Overgrowth: A Narrative Review. Nutrients. 2025;17(9):1410. doi:10.3390/nu17091410 ↩
- Rezaie A, Buresi M, Lembo A, et al.. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. American Journal of Gastroenterology. 2017;112(5):775-784. doi:10.1038/ajg.2017.46 ↩
- Bogdanowska-Charkiewicz D, Górski P, Jurkowska G, et al.. Effectiveness of the low FODMAP diet in patients with irritable bowel syndrome and small intestine bacterial overgrowth syndrome. Frontiers in Nutrition. 2026;13:1725524. doi:10.3389/fnut.2026.1725524 ↩
- Nasser J, Mehravar S, Pimentel M, et al.. Elemental Diet as a Therapeutic Modality: A Comprehensive Review. Digestive Diseases and Sciences. 2024;69(9):3344-3360. doi:10.1007/s10620-024-08543-1 ↩
- Stanford Health Care. Low FODMAP Diet. Stanford Health Care Clinical Nutrition Services. 2026. Available at: https://stanfordhealthcare.org/content/dam/SHC/for-patients-component/programs-services/clinical-nutrition-services/docs/pdf-lowfodmapdiet.pdf ↩
- Rezaie A, Chang BW, de Freitas Germano J, et al.. Effect, Tolerability, and Safety of Exclusive Palatable Elemental Diet in Patients With Intestinal Microbial Overgrowth. Clinical Gastroenterology and Hepatology. 2025;23(12):2306-2317.e7. doi:10.1016/j.cgh.2025.03.002 ↩
- University Hospitals Clinical Nutrition Services. Low FODMAP Diet for Patients with Irritable Bowel Syndrome. University Hospitals. 2026. Available at: https://www.uhhospitals.org/services/clinical-nutrition-services/patient-resources/diet-information/low-fodmap-diet-for-patients-with-irritable-bowel-syndrome ↩
- Deloose E, Janssen P, Depoortere I, Tack J. The migrating motor complex: control mechanisms and its role in health and disease. Nature Reviews Gastroenterology & Hepatology. 2012;9(5):271-285. doi:10.1038/nrgastro.2012.57 ↩
- Furnari M, Parodi A, Gemignani L, et al.. Clinical trial: the combination of rifaximin with partially hydrolysed guar gum is more effective than rifaximin alone in eradicating small intestinal bacterial overgrowth. Alimentary Pharmacology & Therapeutics. 2010;32(8):1000-1006. doi:10.1111/j.1365-2036.2010.04436.x ↩
- Mehravar S, Takakura W, Wang J, Pimentel M, Nasser J, Rezaie A. Symptom Profile of Patients With Intestinal Methanogen Overgrowth: A Systematic Review and Meta-analysis. Clinical Gastroenterology and Hepatology. 2025;23(7):1111-1122.e9. doi:10.1016/j.cgh.2024.07.020 ↩
- Quigley EM, Murray JA, Pimentel M. AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review. Gastroenterology. 2020;159(4):1526-1532. doi:10.1053/j.gastro.2020.06.090 ↩
- Shah A, Holtmann G, Gibson PR. Critical Review: The Past, Present, and Future of Small Intestinal Bacterial Overgrowth (SIBO). JGH Open. 2026;10(5):e70419. doi:10.1002/jgh3.70419 ↩