SIBO
Bacteria in the wrong place. SIBO occurs when bacteria that should be in your colon migrate up into your small intestine. They ferment food you're trying to digest, causing bloating, pain, and stealing your nutrients. It's one of the most common causes of IBS symptoms.
SIBO Symptoms
Bloating
The hallmark symptom. Distension after eating, especially carbs and fiber. "Pregnant" appearance.
Gas & Belching
Excessive flatulence. Bacteria ferment food producing hydrogen, methane, or hydrogen sulfide.
Diarrhea or Constipation
Hydrogen-dominant = diarrhea. Methane-dominant (IMO) = constipation. Can alternate.
Nutrient Deficiencies
B12, iron, fat-soluble vitamins. Bacteria consume nutrients before you absorb them.
Fatigue
From malabsorption, inflammation, and bacterial toxins entering bloodstream.
Brain Fog
D-lactic acidosis from certain bacteria. Ammonia production. Gut-brain axis disruption.
What Causes SIBO
Impaired Motility
- MMC dysfunction: Migrating motor complex sweeps bacteria down every 90 min (fasted)
- Hypothyroidism: Slows gut motility, allows bacterial buildup
- Diabetes: Gastroparesis, autonomic neuropathy
- Post-food-poisoning: Autoimmune damage to gut nerves (anti-vinculin)
- Opioids: Strongly inhibit motility
Structural & Other
- Low stomach acid: First line defense against bacteria
- PPI use: Raises pH, bacteria survive
- Ileocecal valve dysfunction: Backflow from colon
- Adhesions/strictures: Surgery, Crohn's, endometriosis
- Stress: Slows motility via vagus nerve
Types of SIBO
Hydrogen SIBO
Bacteria produce hydrogen gas. Typically causes diarrhea. More common form.
Methane (IMO)
Archaea produce methane from hydrogen. Causes constipation. Now called IMO (intestinal methanogen overgrowth).
Hydrogen Sulfide
Sulfate-reducing bacteria. Diarrhea, rotten egg smell. Newer testing available.
Treatment Approach
Kill Phase
Antibiotics (rifaximin) or herbal antimicrobials. Methane often needs neomycin or allicin added.
Diet During Treatment
Low-FODMAP, elemental diet, or biphasic approach. Starve bacteria while treating.
Prokinetics
CRITICAL for prevention. Motegrity, low-dose erythromycin, ginger, or 5-HTP to restore MMC.
Address Root Cause
Why did it happen? Fix motility issue, optimize stomach acid, manage stress, heal gut nerves.
Meal Spacing
4-5 hours between meals. MMC only works in fasted state. No grazing or constant snacking.
Slow Fiber Reintroduction
After treatment, gradually rebuild microbiome with diverse fibers. Too fast = relapse symptoms.