What Not to Eat if You Have SIBO: Your Guide to a Calmer Gut

January 9, 2026 •

3 min read

According to the American College of Gastroenterology, most dietary approaches for SIBO focus on reducing fermentable carbohydrates that feed harmful bacteria. Understanding what not to eat if you have SIBO is a crucial first step in managing symptoms and improving your gut health. Making strategic dietary changes can help minimize uncomfortable symptoms like bloating, gas, and abdominal pain.

Quick Summary

This guide details the high-FODMAP foods, sugars, dairy, and processed items that may exacerbate symptoms of SIBO. It outlines common food triggers and explains how dietary choices affect bacterial overgrowth in the small intestine, providing a clearer path to symptom management.

Key Points

High-FODMAP foods trigger symptoms: Fermentable carbohydrates like those in onions, garlic, apples, and beans feed overgrown bacteria, leading to gas and bloating.
Avoid processed sugars and artificial sweeteners: High-fructose corn syrup, honey, and sugar alcohols like sorbitol can exacerbate bacterial overgrowth.
Limit certain grains and dairy: Wheat-based products (containing fructans) and lactose-containing dairy should often be reduced or avoided, depending on tolerance.
Personalized diet is key: Because food triggers vary, a short-term elimination diet followed by careful reintroduction, ideally guided by a dietitian, is recommended.
Symptom management is the main goal: Dietary modifications are a tool for controlling symptoms, not a cure for SIBO, and should be part of a broader treatment plan with professional oversight.
Meal spacing can help: Allowing for periods between meals and snacks can stimulate the gut's cleansing waves, which help clear bacteria.

Understanding SIBO and the Role of Diet

Small Intestinal Bacterial Overgrowth (SIBO) is a condition where there is an excessive amount of bacteria in the small intestine. These bacteria ferment undigested food, especially carbohydrates, leading to common gastrointestinal symptoms such as bloating, gas, abdominal pain, and diarrhea. A key strategy for managing SIBO is to limit the foods that act as fuel for this bacterial overgrowth. This often involves a low-FODMAP diet, which reduces the intake of fermentable carbohydrates.

High-FODMAP Foods to Avoid

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These short-chain carbohydrates are poorly absorbed and can be fermented by bacteria, causing SIBO symptoms.

Vegetables High in FODMAPs

Some vegetables can be problematic due to their fermentable carbohydrate content. Common triggers include onions and garlic (due to fructans), cruciferous vegetables like cauliflower and Brussels sprouts, artichokes and asparagus (high in fructans and inulin), and some mushrooms (high in polyols). Individual tolerance varies.

Fruits High in FODMAPs

Many fruits contain high levels of fructose or polyols that can aggravate SIBO symptoms. Examples include apples, pears, mangoes, watermelon (high in fructose/sorbitol), stone fruits like peaches and plums (rich in polyols), and dried fruits like raisins and dates (concentrated sources of FODMAPs).

Sugars, Sweeteners, and Processed Foods

Refined sugars and artificial sweeteners can worsen SIBO by feeding bacteria. High-fructose corn syrup and honey are concentrated fermentable sources. Sugar alcohols (polyols) like sorbitol and xylitol are poorly absorbed and can trigger symptoms, often found in sugar-free products. Processed foods frequently contain hidden sugars and additives that promote bacterial growth.

Grains and Dairy to Limit or Avoid

Certain grains and dairy products are significant sources of FODMAPs. Wheat, rye, and barley contain fructans. Gluten may also be an issue for some. Dairy with lactose can provide fermentable carbohydrates for bacteria for those who are lactose intolerant; lactose-free options or hard cheeses are often better tolerated. Legumes like beans and lentils are high in GOS.

A Comparison of High vs. Low FODMAP Foods

This table provides a simple overview of common high-FODMAP foods to avoid and safer, low-FODMAP alternatives.


Food Category	High-FODMAP (To Avoid)	Low-FODMAP (Safer Option)
Vegetables	Onions, Garlic, Cauliflower, Asparagus	Carrots, Spinach, Bell Peppers, Cucumbers
Fruits	Apples, Pears, Mangoes, Watermelon	Bananas, Oranges, Strawberries, Grapes
Grains	Wheat-based bread, Pasta, Barley	Gluten-free bread, Rice, Quinoa, Oats
Dairy	Milk, Soft Cheeses, Yogurt, Ice Cream	Lactose-free milk, Hard cheeses (e.g., parmesan)
Sweeteners	High-fructose corn syrup, Honey, Sorbitol	Maple syrup, Stevia, White sugar (in moderation)

Dietary Strategies and Considerations

Eliminating foods permanently is not the goal. A typical approach involves a short-term elimination followed by reintroduction to identify personal triggers. Consulting a dietitian is recommended.

Consider your type of SIBO: Hydrogen sulfide-dominant SIBO may require a low-sulfur diet, limiting foods like eggs, garlic, and cruciferous vegetables.
Spacing your meals: Allowing longer periods between meals helps trigger the gut's migrating motor complex (MMC), which clears bacteria.
Hydration: Drinking enough water supports digestive health.
Herbal supplements: Some herbal antimicrobials, under professional guidance, may also help.

Conclusion

Understanding what not to eat if you have SIBO is key to managing symptoms. Focusing on low-FODMAP foods, avoiding processed sugars, and identifying personal triggers can reduce discomfort. Dietary changes are often most effective with professional guidance and should be part of a broader treatment plan. The aim is a balanced diet promoting long-term digestive wellness. For more information, consult an authoritative source like the Cleveland Clinic.

Frequently Asked Questions

The low-FODMAP diet is a temporary elimination diet that restricts foods high in fermentable carbohydrates (FODMAPs) that feed bacteria in the small intestine. It is not a permanent solution but helps identify trigger foods and reduce symptoms.

No, not all vegetables are safe. High-FODMAP vegetables like onions, garlic, cauliflower, and asparagus should typically be avoided or limited, especially during the elimination phase. Low-FODMAP vegetables like carrots, spinach, and bell peppers are generally better tolerated.

Sugar and many artificial sweeteners are easily fermented by bacteria, fueling overgrowth. Sugars like high-fructose corn syrup and alcohols like sorbitol are common triggers that can worsen gas, bloating, and other SIBO symptoms.

Most wheat, rye, and barley products are high in fructans and should be avoided. However, many people can tolerate low-FODMAP, gluten-free grains like rice, quinoa, and oats.

The best way to identify your personal triggers is through a structured elimination and reintroduction diet, preferably under the supervision of a registered dietitian. Journaling your meals and symptoms can also be very helpful.

Dairy products containing lactose, like milk, soft cheeses, and yogurt, can be problematic for those with SIBO and lactose intolerance. Many people can tolerate lactose-free dairy alternatives or hard, aged cheeses, which are naturally low in lactose.

The role of fiber in SIBO is debated, and tolerance varies. Some high-fiber foods can increase fermentation, while others can be beneficial. It is often recommended to initially limit high-fiber foods and then reintroduce them carefully to see how you respond.