Understanding SIBO: Causes, Symptoms, and Solutions

Understanding SIBO: Causes, Symptoms, and Solutions

Small Intestinal Bacterial Overgrowth (SIBO) is a hidden root cause of many digestive disorders and it is more common than you might think. From unexplained bloating to chronic constipation, SIBO can masquerade as IBS, nutrient deficiencies, and fatigue. If you're a patient or practitioner trying to make sense of breath tests and gut symptoms, this article will walk you through the essentials of SIBO, I based it on the clinical interpretive guide from Genova Diagnostics.

What is SIBO?

SIBO occurs when excessive bacteria, often colonic in origin, migrate into the small intestine where they don't belong. These bacteria ferment carbohydrates from our diet, releasing gases such as hydrogen (H₂), methane (CH₄), or hydrogen sulfide (H₂S). The result? Gas, bloating, abdominal pain, and altered bowel habits.

Common organisms involved include:

• Escherichia coli

• Klebsiella pneumonia

• Enterococcus spp.

• Methanobrevibacter smithii (a methane-producing archaea)

  
  

SIBO Symptoms

The symptoms of SIBO are wide-ranging and often overlap with other GI disorders:

• Bloating after meals

• Abdominal pain or discomfort

• Diarrhea or constipation

• Nausea

• Fatigue

• Unexplained weight loss

  
  

Methane-dominant SIBO, also known as Intestinal Methanogen Overgrowth (IMO), is particularly associated with constipation and slow transit.

Who’s at Risk?

Many conditions increase the likelihood of developing SIBO:

• IBS or other functional GI disorders

• Diabetes

• Hypothyroidism

• Fibromyalgia

• Liver or pancreatic disease

• Autoimmune disease

• Rosacea or chronic skin issues

  
  

Risk factors include impaired gut motility, reduced stomach acid or bile production, and immune dysfunction factors that interfere with the body’s natural defenses against bacterial overgrowth.

Complications of Untreated SIBO

SIBO isn't just uncomfortable, it can lead to serious complications:

• Malabsorption and nutrient deficiencies (B12, iron, vitamins A, D, E, K)

• Weight loss and steatorrhea (fat in stools)

• Anemia

• Osteoporosis

• Neuropathy

• Leaky gut and inflammation

  
  

Diagnosing SIBO: The Breath Test

SIBO - Kit-Based, Breath Test

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Genova’s SIBO breath test measures hydrogen and methane levels after ingesting lactulose. Key indicators of a positive test include:

• Hydrogen rise ≥20 ppm by 90 minutes

• Methane ≥10 ppm at any point

• Symptoms with borderline methane (3–9 ppm) may still warrant treatment

  
  

Patients with false negatives might be hydrogen sulfide producers or have issues with sample collection timing.

Treatment Options

1. Antibiotics

• Rifaximin: Effective for hydrogen-dominant SIBO

• Rifaximin + Neomycin: Often used for methane-dominant cases

• Other options include metronidazole and doxycycline

  
  

2. Natural Antimicrobials

• Berberine

• Allicin (from garlic)

• Oregano oil

• Neem

  
  

Studies show herbal therapies may be as effective as antibiotics.

3. Elemental Diet

A short-term liquid diet that starves bacteria while nourishing the patient.

4. Nutritional & Functional Support

• Digestive enzymes, HCl, bile acids

• Brush border healing agents: glutamine, colostrum, licorice, slippery elm

• Avoid prebiotics during treatment (they can feed the overgrowth)

  
  

Long-Term Success: Fixing the Root Cause

SIBO often recurs if the underlying cause isn't addressed. Key strategies include:

• Supporting the Migrating Motor Complex (MMC) with meal spacing (every 4–5 hours)

• Using prokinetics like ginger, Iberogast, or low-dose naltrexone

• Treating comorbidities like hypothyroidism or post-infectious IBS

  
  

Final Thoughts

SIBO represents a condition that extends beyond gut health because it impacts your entire body system. The proper diagnosis and treatment of SIBO through testing provides actual relief for people who experience persistent digestive symptoms or care for someone with ongoing gastrointestinal issues.

A practitioner who understands both the test and the patient needs to work with you when you suspect SIBO or want to properly interpret a breath test.

Think You Might Have SIBO?

SIBO - Kit-Based, Breath Test

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Stop guessing and start testing. The process of healing your gut begins with determining the actual gut condition.

References:

SIBO Test | Small Intestinal Bacterial Overgrowth Test. (n.d.-b). https://www.gdx.net/products/sibo?section=support-materials