The Purpose of the SIBO Prep Diet
A small intestinal bacterial overgrowth (SIBO) test is a hydrogen and methane breath test that measures the gases produced by bacteria in your gut. The test involves drinking a sugar solution and breathing into a device at intervals. Bacteria in the small intestine will ferment the solution and produce gas if there is an overgrowth. To prevent misleading results, a specific low-fermentation, low-fiber diet, sometimes called the 'white diet,' is required for 12 to 48 hours before the test.
Allowed Foods on the SIBO Prep Diet
A strict diet is essential for accurate SIBO test results. The focus is on easily digestible, low-fiber foods that won't ferment and produce gas.
Proteins
- Plain-cooked meat, poultry, fish, and eggs (baked, broiled, or grilled) seasoned with only salt and pepper.
- Clear meat broth made without added vegetables, bone, or cartilage.
Carbohydrates
- Plain, steamed white rice is typically the only grain allowed. Some protocols also permit plain white bread or crackers without seeds.
Fats and Liquids
- Coconut, olive, vegetable oils, butter, or lard for cooking.
- Plain water during the 12-hour fast and throughout the test.
- Unsweetened, uncreamed weak black coffee or tea before the 12-hour fast. Herbal teas are often restricted.
Foods to Avoid Before Your SIBO Test
Avoid fermentable foods to prevent inaccurate test results.
Restricted Food Categories
- All Grains (except plain white rice): Whole grains, cereals, brown rice, quinoa, pasta.
- Fruits and Vegetables: Nearly all fresh, dried, and juiced fruits and vegetables, including potatoes, leafy greens, broccoli, beans, and onions.
- Dairy and Legumes: All dairy products (except some hard cheeses in specific protocols) and legumes like beans, lentils, and chickpeas.
Other Prohibited Items
- Processed meats like deli meat.
- Natural and artificial sweeteners.
- Spices, herbs, garlic, and onion (only salt and pepper allowed).
- Alcohol, soda, and fruit juices.
- Many supplements, probiotics, and certain medications; consult your doctor for specifics.
SIBO Prep Diet: A Quick Comparison
| Food Category | Allowed Before SIBO Test | Prohibited Before SIBO Test |
|---|---|---|
| Protein | Plain baked/broiled chicken, fish, turkey, eggs | Processed meats, sausages, cured meats, deli meat |
| Carbohydrates | Plain steamed white rice, white bread, plain crackers | Whole grains, brown rice, pasta, cereals, oats, bran |
| Vegetables | None | Almost all fresh, frozen, or canned vegetables |
| Fruits | None | All fresh, dried, or juiced fruits |
| Dairy | Hard cheeses (Parmesan) in some protocols, Eggs | Milk, yogurt, ice cream, soft cheeses |
| Fats | Coconut/olive/vegetable oils, butter, lard | Flavored oils, dressings |
| Liquids | Plain water, clear meat broth, weak black coffee/tea | Alcohol, fruit juice, soda, sweetened beverages |
| Seasonings | Salt, pepper | All other herbs, spices, garlic, onions |
Fasting Before the Test
A 12-hour fast, with only plain water allowed, is required after the prep diet. This clears the small intestine for accurate gas readings. On the test morning, avoid vigorous exercise, smoking, and mouthwash.
Special Considerations for Vegetarians and Vegans
Vegetarian and vegan individuals need to consult their healthcare provider for specific SIBO prep instructions. Options might include a 24-hour fast or tofu as a protein source. A 48-hour diet might be needed for constipation. Always follow your doctor's guidance.
Conclusion
Following a strict, low-fermentation diet and a 12-hour fast before a SIBO test is critical for accurate results. Adhering to allowed foods like white rice, plain proteins, and clear broth creates optimal testing conditions. Always confirm specific instructions with your healthcare provider. Resources like the SIBO Center can provide further details on preparation.
General Prep & Meal Ideas: SIBO Test Diet
Example Menu for SIBO Prep Diet (Day Before Test):
- Breakfast: Scrambled eggs with salt and pepper.
- Lunch: Baked chicken breast with salt and pepper, and plain white rice.
- Dinner: Broiled fish seasoned with salt and pepper.
- Snack (if before fast): Clear meat broth.
- Fluids: Weak black coffee or tea (unsweetened, uncreamed), plain water.
Stop eating and drinking (except water) at least 12 hours before your test.
