Nutrition and SIBO: What sugars should I avoid with SIBO? A Comprehensive Guide

October 6, 2025 •

4 min read

Small intestinal bacterial overgrowth (SIBO) patients often experience increased gas and bloating after consuming certain sugars, which serve as fuel for the overgrown bacteria. Learning what sugars should I avoid with SIBO is a key component of managing symptoms and supporting treatment. This guide breaks down the science behind fermentable sugars and provides actionable advice on diet.

Quick Summary

An abnormal bacterial overgrowth in the small intestine causes uncomfortable symptoms by fermenting specific carbohydrates. Managing SIBO involves limiting high-FODMAP sugars, including fructose, lactose, and sugar alcohols, to reduce bacterial food sources and relieve digestive distress. Safe alternatives and diet strategies are discussed.

Key Points

Avoid High-FODMAP Sugars: Fructose (in honey, agave, apples), Lactose (in dairy), and Polyols (sugar alcohols like sorbitol and xylitol) feed SIBO-causing bacteria.
Limit Sugar-Free Sweeteners: Many sugar-free products contain sugar alcohols like xylitol or sorbitol that are poorly absorbed and can trigger SIBO symptoms.
Choose SIBO-Friendly Alternatives: Opt for sweeteners that are not readily fermented, such as stevia, monk fruit extract, and small amounts of glucose or maple syrup.
Follow a Short-Term Low-FODMAP Diet: A temporary elimination diet focused on low-fermentable carbohydrates can help reduce symptoms by starving the bacteria.
Reintroduce with Caution: Once on the low-FODMAP diet, reintroduce high-FODMAP sugars one by one to test your individual tolerance levels.
Seek Professional Guidance: Work with a registered dietitian or healthcare provider to navigate the diet safely and ensure proper nutrition while managing SIBO.

The Link Between Sugars, Bacteria, and SIBO Symptoms

Small Intestinal Bacterial Overgrowth (SIBO) is a condition where there is an excessive amount of bacteria in the small intestine, which typically has a low bacterial count. These misplaced bacteria ferment undigested carbohydrates, releasing gases like hydrogen and methane that lead to common SIBO symptoms such as bloating, abdominal pain, and diarrhea. The primary culprits are short-chain carbohydrates known as FODMAPs: Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. By understanding and limiting the intake of high-FODMAP sugars, individuals can help starve the overgrown bacteria and reduce symptom severity.

The Culprits: High-FODMAP Sugars to Avoid

To effectively manage SIBO symptoms, it is crucial to identify and avoid the specific types of fermentable sugars that feed the intestinal bacteria. These include natural sugars found in fruits and dairy, as well as artificial sweeteners.

Fructose: A simple sugar present in many fruits and vegetables. Fructose malabsorption is common in SIBO patients, where excess fructose is fermented by bacteria in the small intestine, creating gas and discomfort. Foods high in fructose include apples, pears, mangoes, honey, and high-fructose corn syrup. Even "natural" sugars like honey and agave are high in fructose and should be avoided.
Lactose: The sugar found in milk and dairy products. Damage to the small intestine lining caused by SIBO can lead to temporary lactose intolerance. For many, the problem isn't the lactose itself but rather its fermentation by the bacterial overgrowth. Dairy products like cow's milk, ice cream, and soft cheeses are high in lactose and should be avoided.
Polyols (Sugar Alcohols): These are commonly used as low-calorie sweeteners in sugar-free products and are also naturally found in some fruits and vegetables. Because they are poorly absorbed in the small intestine, they become a prime food source for bacteria. Polyols include xylitol, sorbitol, mannitol, and erythritol. You can find these in sugar-free gums, mints, and certain diet drinks.
Sucralose (Splenda): Some sources indicate that sucralose can exacerbate SIBO symptoms and should be avoided.

Tolerated Sweeteners and Low-FODMAP Alternatives

While the list of high-FODMAP sugars may seem daunting, there are several sweeteners that are generally well-tolerated by individuals with SIBO. The key is moderation and listening to your body's individual response.

Glucose: A simple sugar that is easily and rapidly absorbed in the small intestine, leaving little for the bacteria to ferment. It is often used in SIBO breath testing because it should not produce fermentation gas in a healthy small bowel.
Sucrose (Table Sugar): As a disaccharide composed of glucose and fructose, it can sometimes be tolerated in small amounts, particularly if fructose malabsorption is not a primary issue. However, some healthcare professionals advise caution.
Stevia: A plant-based, zero-calorie sweetener derived from the Stevia rebaudiana plant. It is not a fermentable carbohydrate and does not feed gut bacteria.
Monk Fruit Extract: Also a zero-calorie, plant-based sweetener that is not fermented by gut bacteria and is generally considered safe for SIBO patients.
Maple Syrup: Pure maple syrup can be a low-FODMAP option in limited, controlled portions.

Comparison Table: SIBO-Unfriendly vs. SIBO-Friendly Sweeteners


Feature	High-FODMAP Sugars (Avoid)	Low-FODMAP Sweeteners (Tolerated in Moderation)
Primary Carbohydrate Type	Fructose (monosaccharide), Lactose (disaccharide), Polyols (sugar alcohols)	Glucose (monosaccharide), sucrose (disaccharide), other non-fermentable options
Digestive Impact	Poorly absorbed in the small intestine, fermented by bacteria, causing gas and bloating	Easily absorbed or not fermentable by gut bacteria, minimizing fermentation and symptoms
Common Examples	Fructose (apples, honey, agave), Lactose (milk, ice cream), Polyols (sorbitol, xylitol)	Glucose, table sugar (sucrose), pure maple syrup
Sugar-Free Options	Many sugar-free products contain polyols like sorbitol and xylitol	Stevia and monk fruit sweeteners
Hidden Sources	High-fructose corn syrup in sodas, sweetened snacks, and condiments	Check labels for added sugars, even in low-FODMAP options

Adopting a Low-FODMAP Approach to Sugar

Managing sugar intake for SIBO typically involves following a structured low-FODMAP diet plan. This is an elimination diet, not a long-term solution, and should be undertaken with professional guidance to avoid nutritional deficiencies.

Elimination Phase: For an initial period of 2-6 weeks, you will eliminate high-FODMAP foods, including problematic sugars and sweeteners. This is designed to reduce symptoms by starving the overgrown bacteria.
Reintroduction Phase: After symptoms improve, you will systematically reintroduce high-FODMAP foods, one group at a time, to identify your personal trigger foods and tolerance levels. Some individuals may tolerate certain high-FODMAP foods in small quantities.
Personalization: The goal is to develop a personalized, less restrictive diet for long-term symptom management while reintroducing as much variety as possible. A registered dietitian can provide specific guidelines and support throughout this process.

The Importance of Professional Guidance

While dietary changes are a cornerstone of SIBO management, they are most effective when part of a comprehensive treatment plan that may also include antibiotics or other therapies. It is essential to work with a healthcare provider or a registered dietitian who can help you develop a safe and effective plan. They can also ensure you maintain proper nutrition and address any underlying issues that contribute to SIBO. The ultimate goal is to move beyond strict elimination and find a sustainable, healthy diet that minimizes your symptoms.

Conclusion

For those with SIBO, the types of sugar consumed directly impact symptom severity by feeding the bacterial overgrowth in the small intestine. Key sugars to avoid include fructose, lactose from dairy, and sugar alcohols (polyols) found in many "sugar-free" products. Instead, focusing on a temporary low-FODMAP diet and using well-tolerated sweeteners like glucose, stevia, or monk fruit can help manage symptoms during treatment. The low-FODMAP diet is a short-term tool for identification and personalization, not a permanent eating plan, highlighting the importance of working with a healthcare professional. For more in-depth information, the Cleveland Clinic offers extensive resources on the low-FODMAP diet.

Frequently Asked Questions

High-FODMAP sugars are short-chain carbohydrates that are poorly absorbed in the small intestine and fermented by bacteria, causing gas and bloating. Low-FODMAP sweeteners are either easily absorbed (like glucose) or not fermented by bacteria (like stevia), which makes them less likely to cause symptoms.

No, honey is generally not a safe sweetener for a SIBO diet because it contains high levels of fructose, a high-FODMAP sugar that feeds the overgrown bacteria in the small intestine.

Many people with SIBO should initially avoid dairy containing lactose, as the bacterial overgrowth can lead to temporary lactose intolerance. Some may tolerate lactose-free dairy or hard cheeses, which are naturally low in lactose.

No, you should avoid sugar alcohols like sorbitol, mannitol, and xylitol. These are polyols, a type of FODMAP that is poorly absorbed and can be fermented by gut bacteria, causing gas and other symptoms.

The initial elimination phase of a SIBO diet, where problematic sugars are avoided, typically lasts between 2 and 6 weeks. After this, you should begin reintroducing foods with professional guidance to identify your personal tolerance levels.

No, natural sugars like agave nectar and coconut sugar are still problematic because they are high in fructose, which feeds the bacterial overgrowth. It is best to avoid them during SIBO treatment.

Safe sugar substitutes for SIBO patients include natural, non-caloric sweeteners like stevia and monk fruit extract, as they do not feed gut bacteria. Small, portion-controlled amounts of glucose, sucrose, or maple syrup may also be tolerated.