Small Intestinal Bacterial Overgrowth (SIBO)

Small Intestinal Bacterial Overgrowth - symptoms and natural treatments

Understanding the Origin, Subtypes, and Functional Medicine Treatment Protocols of SIBO

Small Intestinal Bacterial Overgrowth (SIBO) is a gastrointestinal disorder characterized by an abnormal increase in bacterial population within the small intestine. This overgrowth disrupts the normal digestive processes, leading to a range of symptoms that can significantly impact an individual’s quality of life. Unfortunately, SIBO is frequently overlooked by conventional medical practitioners, highlighting the importance of functional medicine in both diagnosis and treatment.

Understanding SIBO

Prevalence and Impact

SIBO is a widespread disorder, affecting at least 39 million people. It is particularly prevalent among individuals with Irritable Bowel Syndrome (IBS), contributing to the manifestation of IBS-like symptoms, such as abdominal pain, irregular bowel movements, and bloating. The small intestine, where SIBO occurs, is supposed to have a relatively low concentration of bacteria. However, when bacterial levels increase, the fermentation of dietary carbohydrates produces excess gas, leading to various symptoms.

Subtypes of SIBO

1. Hydrogen (H2)-Dominant SIBO

This subtype is characterized by elevated hydrogen gas levels on the SIBO breath test. Overgrowth of bacteria such as Streptococcus, E. coli, Staphylococcus, and others is associated with H2-dominant SIBO. This subtype is often linked to IBS with diarrhea (IBS-D).

2. Intestinal Methanogen Overgrowth (IMO)

Previously known as methane (CH4) dominant-SIBO, IMO involves the overgrowth of methanogens, particularly Methanobrevibacter smithii, in the intestines. It is more strongly correlated with IBS-constipation (IBS-C).

3. Hydrogen Sulfide (H2S)-Dominant SIBO

This recently discovered subtype is characterized by excess bacterial production of hydrogen sulfide gas. Bacteria such as Escherichia, Klebsiella, Proteus, and Desulfovibrio are associated with H2S-dominant SIBO, and it is more commonly linked to diarrhea.

Symptoms of SIBO

SIBO symptoms arise from bacterial fermentation, immune activation, inflammation, increased intestinal permeability, and poor nutrient absorption. Common symptoms include abdominal pain, gas, bloating, diarrhea, heartburn, and reflux. Leaky gut caused by SIBO may also result in extraintestinal symptoms like fatigue, brain fog, headaches, mood changes, skin issues, and joint pain.  These symptoms mimic many symptoms of mycotoxin (mold) illness, so it makes sense to test for both if your budget allows.  Remember, you can have both issues.  Ultimately, you are looking for the root cause of your symptoms, and you may have more than one cause.

Causes of SIBO

Several factors contribute to the development of SIBO, including:

  • Reduced stomach acid and digestive enzymes
  • Diminished migrating motor complex (MMC) and slowed intestinal motility
  • Intestinal and abdominal structural abnormalities
  • Ileocecal valve stuck open due to chronic stress, allowing backflow from the colon

Medications, medical conditions, and lifestyle habits can also play a role in predisposing individuals to SIBO.

Diagnosing SIBO

SIBO can be diagnosed through a small intestinal aspirate culture, a breath test, or an Organic Acids Test which can be run by an Integrative Health Practitioner. The breath test, which measures bacterial fermentation gas products exhaled through the lungs, is more commonly used due to its non-invasive nature. Additionally, testing for antibodies like vinculin and CdtB can confirm post-infectious IBS as a cause of SIBO.

Functional Medicine Labs for Personalized Treatment

Functional medicine and Integrative Health Practitioners often utilize various tests to personalize SIBO treatment plans. These include:

  • Organic Acids Test:  Identifies specific metabolic waste that are only present when certain bacteria, fungi, or yeasts are present in the gut.
  • Gut Bacteria and Parasite Test: Identifies digestive enzyme deficiencies, inflammation, and dysbiosis.
  • Cortisol Testing: Identifies chronic stress and cortisol imbalances affecting gut function.
  • Micronutrient Testing: Assesses nutrient deficiencies caused by SIBO.
  • Thyroid Panel: Screens for suboptimal thyroid function impacting gut health.
  • Hemoglobin A1c (HbA1c): Diagnoses diabetes-related nerve damage affecting intestinal motility.
  • Imaging: May be necessary to confirm structural abnormalities and motility issues.

Functional Medicine Treatment Protocol for SIBO

Given the complexity of SIBO pathogenesis, a personalized approach is crucial for effective treatment. The following outlines a basic protocol for patients with Hydrogen (H2) and Hydrogen Sulfide (H2S) SIBO subtypes.

Therapeutic Diet and Nutrition

  • Elemental Diet: Replace all meals with a predigested elemental formula for two weeks to starve bacteria. Effective for severe cases.
  • Palliative Diets: Low FODMAP, Specific Carbohydrate, Bi-Phasic, GAPS, or Cedars-Sinai diets can provide symptom relief. Meal spacing is also emphasized.

Prescription Antibiotic Protocol

  • Rifaximin (Xifaxan): First-line antibiotic for H2 and H2S SIBO. A two-week course may be required, and multiple courses may be needed for complete eradication.

Herbal Antibiotic Protocol

  • Berberine, Oregano, Neem: Broad-spectrum antimicrobials effective against bacteria, fungi, and parasites. Six weeks of treatment is recommended.
  • FC-Cidal & Dysbiocide, Candibactins: Combination formulas effective in eradicating SIBO. Six weeks of treatment is advised.

Additional Supplements

  • Prokinetics: Motility Activator, containing ginger and artichoke, supports the MMC and prevents relapse after antimicrobial treatment. Continuation for up to 4 months post-SIBO eradication is recommended.

Monitoring and Retesting

Repeating the SIBO breath test after antimicrobial therapy is unnecessary but can help monitor treatment progress. Success is considered when patients report an 80-90% improvement in symptoms. Alternatively, monitoring symptoms may guide further treatment decisions.  It also might be a good idea to do an Omega-3 test to check inflammation levels in the body.

SIBO is a complex disorder that requires a multifaceted approach for effective diagnosis and treatment. Functional medicine plays a crucial role in addressing the root causes of SIBO and implementing personalized protocols to prevent recurrence and support overall gastrointestinal health. Regular monitoring by your Integrative Health Practitioner and retesting are essential for assessing treatment progress and making informed decisions about ongoing care.

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Further Reading: Gut Bacterial Overgrowth


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