What is SIBO? Understanding Causes, Symptoms, and Functional Medicine Treatments for Small Intestinal Bacterial Overgrowth

Introduction:

If you're struggling with persistent bloating, abdominal pain, or digestive discomfort, you may have been told that it's "just IBS" or stress. But there's a deeper underlying issue that often goes undiagnosed—Small Intestinal Bacterial Overgrowth, or SIBO.

SIBO occurs when bacteria, which are normally found in the large intestine, start to accumulate in the small intestine. This bacterial imbalance (aka dysbiosis) disrupts your digestion, causing a cascade of downstream effects and uncomfortable symptoms, such as bloating, constipation, diarrhea, and even anxiety. If you’ve been feeling frustrated and exhausted, constantly searching for relief, you're not alone. It's estimated that approximately 39 million people have SIBO.  I believe that addressing the root cause—like SIBO—can bring lasting relief and help you regain your health, energy, and freedom.

What is SIBO?

SIBO (Small Intestinal Bacterial Overgrowth) refers to an excessive growth of bacteria in the small intestine. The small intestine is where most nutrient absorption occurs, and it normally contains only a small amount of bacterial species compared to the large intestine. However, when bacteria from the large intestine move up to the small intestine or when there’s an overgrowth of bacteria in the small intestine itself, digestive function becomes impaired. 

How does SIBO occur? There are several factors that can contribute to the development of SIBO:

• Poor gut motility: When the muscles of the small intestine don't move food along properly, bacteria can accumulate. What lowers the motility? Stress, frequent eating, low thyroid function, diabetes, gastroparesis are common issues associated with motility. You can read more about motility in THIS POST.
• Low stomach acid: Stomach acid (and other digestive enzymes) helps kill bacteria before they reach the small intestine. When acid levels are low, bacteria can thrive. Chronic stress, use of certain medications, H. Pylori and gallbladder removal can contribute to enzyme issues. HERE'S more info about low stomach acid. 
• Anatomical abnormalities or surgery: Scarring from surgery, diverticula, or structural issues can create pockets where bacteria can grow.
• Chronic stress: High stress levels can disrupt the gut-brain connection, slow motility, and contribute to SIBO over time. 

Symptoms of SIBO:

Many people with SIBO experience overlapping symptoms with other conditions, making it challenging to diagnose. Common signs of SIBO include:

• Bloating and gas, often within 30 minutes of eating
• Abdominal pain and cramping
• Diarrhea, constipation, or both (alternating bowel patterns)
• Nausea or acid reflux
• Unexplained fatigue
• Nutrient deficiencies (such as B12 or iron)
• Food intolerances or sensitivities (especially to carbohydrates)
• Anxiety and mood swings

From a functional medicine perspective, we understand that gut imbalances like SIBO can impact more than just your digestion. The gut-brain axis is a powerful connection, meaning your gut health can directly affect your mental and emotional well-being. Many women I work with report that along with digestive discomfort, they also struggle with brain fog, anxiety, and difficulty concentrating.

How Functional Medicine Addresses the Root Causes of SIBO:

The conventional approach to SIBO often involves antibiotics like rifaximin. While antibiotics can be helpful in some cases, they don't address the root causes of SIBO and may only offer temporary relief - which means that symptoms get better for a bit, but then things come roaring back. If you've been stuck in that cycle before, you know how defeated it can feel. In functional medicine, we take a more comprehensive approach to both heal the gut and prevent recurrence.

Here are some key aspects of a functional medicine approach:

1. Identifying and Treating the Underlying Causes: Functional lab testing (like a GI MAP) is crucial to understand whether gut motility issues, low stomach acid, or other factors are contributing to your SIBO. Treating these underlying causes is essential for long-term success. Wonder about testing? CLICK HERE.

2. Dietary Changes: A low FODMAP or SIBO-specific diet is often recommended to reduce bacterial fermentation and starve the overgrowth. However, it’s essential to remember that this is a temporary measure. The ultimate goal is to reintroduce foods as you heal the gut, allowing for a more balanced and sustainable diet. If you've been doing a diet like this for more than 3 months- GET HELP!

3. Herbal Antimicrobials: Instead of relying solely on antibiotics, many functional medicine practitioners use herbal antimicrobials like berberine, oregano oil, and garlic extract, which are equally effective at reducing bacterial overgrowth without disrupting the entire microbiome. 

4. Gut Healing Protocol: Healing the gut lining is vital to prevent recurrence. Supplements like L-glutamine, slippery elm, and collagen can support gut barrier integrity, while probiotics help restore a healthy microbiome balance. Always check with your provider before starting supplements! 

5. Managing Stress: Chronic stress is often an overlooked contributor to SIBO. By addressing stress through lifestyle changes, mindfulness practices, and nervous system support, we can help improve gut-brain communication and prevent flare-ups. Want some stress busting tips? CLICK HERE

What Happens if SIBO is Left Untreated?

Untreated SIBO can lead to long-term health issues such as chronic inflammation, malnutrition, and the development of other conditions like leaky gut, autoimmune diseases, and hormone imbalances. That’s why it’s essential to address SIBO early and effectively, focusing on a root-cause approach that brings lasting relief.

Take the First Step Towards Relief:

If you're tired of struggling with digestive issues, anxiety, and fatigue, there’s a solution. Functional medicine provides a comprehensive, personalized approach to healing your gut and restoring your health. By identifying the root cause of your symptoms, whether it’s SIBO, leaky gut, or another imbalance, we can create a plan that works for your unique needs.

Book a free consultation with me today to get started on your journey to better gut health. Together, we’ll identify what’s been holding you back and build a path forward that helps you regain your energy, mental clarity, and freedom from digestive discomfort.

References:

Chedid V, Dhalla S, Clarke JO, Roland BC, Dunbar KB, Koh J, Justino E, Tomakin E, Mullin GE. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Glob Adv Health Med. 2014 May;3(3):16-24. doi: 10.7453/gahmj.2014.019. PMID: 24891990; PMCID: PMC4030608.

Greenan, S. (2021, November 2). Constant Burping Is A Sign Of This Harmful Bacterial Overgrowth. Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-approach-to-sibo

Pimentel, M., Lembo, A., et al. (2011). Rifaximin therapy for patients with irritable bowel syndrome without constipation. The New England Journal of Medicine, 364(1), 22-32. doi: 10.1056/NEJMoa1004409

Pimentel, M., Saad, R. J., Long, M. D., et al. (2020). ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. The American Journal of Gastroenterology, 115(2), 165–178. https://doi.org/10.14309/ajg.0000000000000501

Rezaie, A., Pimentel, M., & Rao, S. S. C. (2017). How to Test and Treat Small Intestinal Bacterial Overgrowth: an evidence-based approach. Current Gastroenterology Reports, 19(4), 8. doi:10.1007/s11894-017-0559-0

Skrzydło-Radomańska, B., & Cukrowska, B. (2022). How to Recognize and Treat Small Intestinal Bacterial Overgrowth?. Journal of clinical medicine, 11(20), 6017. https://doi.org/10.3390/jcm11206017

Sorathia, S. J., & Rivas, J. M. (2020). Small Intestinal Bacterial Overgrowth. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK546634/

Sroka, N., Rydzewska-Rosołowska, A., Kakareko, K., Rosołowski, M., Głowińska, I., & Hryszko, T. (2022). Show Me What You Have Inside-The Complex Interplay between SIBO and Multiple Medical Conditions-A Systematic Review. Nutrients, 15(1), 90. https://doi.org/10.3390/nu15010090