When it comes to digestive health, there’s a condition that is not widely known, yet impacts many people; Small Intestinal Bacterial Overgrowth (SIBO). If you’ve experienced bloating, abdominal discomfort, or unexplained nutrient deficiencies, SIBO might be part of the picture. Understanding what it is, how it develops, and what foods can help manage symptoms is an important first step in supporting gut health.

What Is SIBO?

SIBO stands for Small Intestinal Bacterial Overgrowth, a condition where bacteria normally found in the large intestine start to grow excessively in the small intestine. While bacteria are essential for gut health, they’re not supposed to be present in high numbers in the small intestine, which is primarily designed for nutrient absorption.

When bacteria overpopulate this part of the digestive tract, they ferment carbohydrates and fibers prematurely, leading to uncomfortable symptoms such as:

• Bloating 
• Gas and abdominal pain
• Diarrhea or constipation (sometimes alternating)
• Nutrient deficiencies, especially B12 and iron
• Fatigue and brain fog

SIBO is usually diagnosed with a breath test that measures hydrogen and methane gases produced by bacterial fermentation.

What Causes SIBO?

Several factors can contribute to the development of SIBO:

1. Slow gut motility – The small intestine relies on something called the “migrating motor complex” (MMC), which acts like a wave to sweep bacteria and food particles into the large intestine. If this process slows, bacteria can accumulate where they shouldn’t.
2. Structural issues – Conditions such as diverticula, adhesions from prior surgeries, or strictures may create pockets where bacteria thrive.
3. Chronic illness – Diseases like diabetes, hypothyroidism, or connective tissue disorders may slow digestion and increase SIBO risk.
4. Medications – Long-term use of proton pump inhibitors (PPIs) and some antibiotics can alter the gut environment.

Nutrition and SIBO: Finding Relief Through Food

Managing SIBO typically involves a combination of medical treatment (like antibiotics or herbal antimicrobials) and nutritional strategies. While no single “SIBO diet” works for everyone, certain foods and approaches may help reduce symptoms and support gut healing.

1. Low-FODMAP Foods

FODMAPs are fermentable carbohydrates that bacteria love to feed on. A low-FODMAP diet reduces these foods temporarily, easing gas and bloating. Examples of lower-FODMAP foods include:

• Proteins: chicken, fish, turkey, eggs
• Vegetables: zucchini, carrots, spinach, cucumber, bell peppers
• Fruits: strawberries, blueberries, grapes, oranges
• Grains: rice, quinoa, gluten-free oats

This approach is meant to be short-term and usually done with guidance from a dietitian, since it can be restrictive.

2. Easily Digestible Carbohydrates

Choosing carbohydrates that are easier to digest can reduce fermentation. White rice, sourdough bread, and well cooked root vegetables may be tolerated better than whole grains or raw, fibrous vegetables.

3. Gut Supporting Proteins and Fats

Protein is essential for maintaining strength and preventing nutrient deficiencies, while healthy fats support satiety and reduce reliance on fermentable carbs. Try:

• Lean poultry, fish, and eggs
• Olive oil, avocado oil, and small amounts of coconut oil
• Lactose-free dairy (if tolerated)

4. Herbs and Spices

Some herbs naturally contain antimicrobial and soothing properties. While not a substitute for medical treatment, they may provide additional support:

• Ginger (aids motility)
• Oregano (mild antimicrobial effect)
• Peppermint (soothes bloating and spasms)

5. Foods to Limit (Temporarily)

Certain foods tend to worsen symptoms during active SIBO:

• High-FODMAP fruits (apples, pears, watermelon)
• Cruciferous vegetables (broccoli, cauliflower, Brussels sprouts)
• Legumes (beans, lentils, chickpeas)
• Onions and garlic (potent FODMAP sources)
• Sugar alcohols (sorbitol, mannitol, xylitol)

It’s important to remember that many of these foods are healthy in general, but during SIBO treatment, reducing them can help calm symptoms.

Lifestyle Habits That Support Recovery

Food is a key part of healing, but lifestyle habits matter too:

• Meal spacing: Allow 4–5 hours between meals to let the MMC “clean up” the small intestine. Constant grazing can disrupt this process.
• Stress management: Chronic stress slows digestion and alters gut function. Breathing exercises, yoga, or mindfulness can help.
• Adequate hydration: Water keeps digestion moving and supports motility.
• Gentle movement: Walking after meals can stimulate digestion.

When to Seek Professional Help

If you suspect SIBO, it’s best not to self-diagnose. Many digestive conditions share similar symptoms, including irritable bowel syndrome (IBS), celiac disease, and lactose intolerance. A gastroenterologist or integrative dietitian can guide you through:

• Appropriate testing (such as breath testing)
• Individualized treatment options (antibiotics, herbal protocols, motility agents)
• A nutrition plan that nourishes without triggering symptoms

Final Thoughts

SIBO can feel overwhelming, but with the right approach, it is manageable. Understanding what it is, why it happens, and how food choices impact symptoms is empowering. While medical treatment is usually necessary, nutrition and lifestyle play a vital role in recovery.

By focusing on low FODMAP foods, easily digestible proteins and carbs, and gut-friendly habits, you can take meaningful steps toward easing discomfort and restoring digestive balance.

References:

References

Ali Rezaie, et al. (2025). Effect, tolerability, and safety of exclusive palatable elemental diet in patients with intestinal microbial overgrowth. Clinical Gastroenterology and Hepatology. Advance publication. DOI: 10.1016/j.cgh.2025.03.002

Gralnek, I. M., Hays, R. D., Kilbourne, A., et al. (2017). A diet low in FODMAPs reduces symptoms in patients with irritable bowel syndrome and a probiotic restores Bifidobacterium species: a randomized controlled trial. Gastroenterology, 153(5), 1518–1529. https://doi.org/10.1053/j.gastro.2017.08.001

Knez, M., Kadac-Czapska, A., & Grembecka, M. (2024). Dietary approaches in the management of small intestinal bacterial overgrowth: The importance of food quality, gut motility, and microbiome. Nutrition, 127, 112114. https://doi.org/10.1016/j.nut.2024.112114

Li, Z., Zhou, Y., Zhao, Y., et al. (2023). Berberine and rifaximin effects on small intestinal bacterial overgrowth: The BRIEF-SIBO study. Frontiers in Pharmacology, 14, 1121435. https://doi.org/10.3389/fphar.2023.1121435

Rezaie, A., Buresi, M., Lembo, A., Lin, H., McCallum, R., Rao, S., Schmulson, M., & Pimentel, M. (2022). Evidence-based and emerging diet recommendations for small intestinal bacterial overgrowth. The American Journal of Gastroenterology, 117(6), 950–959. https://doi.org/10.14309/ajg.0000000000001745

Rezaie, A., Pimentel, M., Leite, G., Mathur, R., & Morales, W. (2025). Effect, tolerability, and safety of exclusive palatable elemental diet in patients with intestinal microbial overgrowth. Clinical Gastroenterology and Hepatology. Advance online publication. https://doi.org/10.1016/j.cgh.2025.03.002

Staudacher, H. M., Whelan, K., Irving, P. M., et al. (2022). Low FODMAP diet reduces gastrointestinal symptoms in irritable bowel syndrome and clinical response could be predicted by symptom severity: a randomized crossover trial. Gut, 71(3), 532–542. https://doi.org/10.1136/gutjnl‐2021‐324366