SIBO Diet Food List PDF

In a healthy digestive system, the small intestine has a relatively low microbial population. Nutrients are absorbed here, and the migrating motor complex (MMC) sweeps debris down into the large colon. When motility slows or when the sterilizing barrier of stomach acid fails, bacteria migrate from the colon upward into the small intestine.

Once colonized in the small intestine, these bacteria feast on dietary carbohydrates, fermenting them prematurely. This fermentation produces large volumes of gas in a narrow, highly sensitive organ, resulting in visible abdominal distension, intestinal wall irritation, and leaky gut. When stomach acid is low, it fails to sterilize food, which allows bacteria to migrate downward and colonize the small intestine. Addressing stomach acid levels through our Low Stomach Acid Protocol is a critical step in preventing relapse.

The specific symptoms you experience depend heavily on the type of gas-producing microbes dominant in your small bowel:

• Hydrogen-Dominant SIBO (H2): Driven by bacteria (such as E. coli and Klebsiella) that ferment carbohydrates directly into hydrogen gas. This gas stimulates rapid peristalsis and draws water into the colon, leading to cramping, pain, and watery diarrhea.
• Methane-Dominant SIBO (CH4): Officially classified as Intestinal Methanogen Overgrowth (IMO). Archaea (specifically Methanobrevibacter smithii) consume the hydrogen produced by other bacteria to generate methane gas. Methane acts as a smooth muscle paralyzer in the GI tract, causing severe constipation, gas retention, and stubborn bloating.
• Hydrogen Sulfide SIBO (H2S): Driven by sulfate-reducing bacteria (like Desulfovibrio or Bilophila wadsworthia) that consume hydrogen gas to produce hydrogen sulfide. H2S acts as a cellular toxin, leading to gas that smells like rotten eggs, diarrhea, abdominal pain, food sensitivities to high-sulfur foods (eggs, garlic, brassicas), and systemic symptoms like joint pain, brain fog, or bladder irritation.

FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) are short-chain sugars and sugar alcohols that are poorly absorbed by human cells but highly prized by gut microbes. When you restrict these fermentable molecules, you cut off the bacteria's primary food source.

Ultimately, diet alone is rarely enough to eradicate the overgrowth. A structured protocol such as the IBS Recovery Protocol is essential to restore proper motility, clear the overgrowth using natural antimicrobials, and heal the damaged intestinal lining. Combining temporary low-FODMAP carbohydrate restriction with targeted motility agents prevents both gas production and bacterial survival.