Small Intestinal Bacterial Overgrowth (SIBO) can lead to or exacerbate Gastroesophageal Reflux Disease (GERD) and sliding hiatal hernias through several mechanisms.

1. Increased Intra-abdominal Pressure

• Gas Production: The excessive bacterial fermentation in SIBO produces large amounts of gas, leading to bloating and increased intra-abdominal pressure. This pressure can push the stomach upwards, potentially causing or worsening a hiatal hernia.
• Reflux Promotion: The increased pressure also promotes the back-flow of stomach contents into the esophagus, leading to GERD symptoms such as heartburn and acid regurgitation.

2. Motility Disorders

• Impaired Gut Motility: SIBO is often associated with dysmotility, where the normal movement of the digestive tract is impaired. This can lead to delayed gastric emptying and increased likelihood of reflux as the stomach contents linger and create pressure.
• Vagus Nerve Dysfunction: The vagus nerve, which controls gut motility, can be affected by chronic inflammation and gut dysfunction caused by SIBO, further contributing to GERD.

3. Diaphragm Dysfunction

• Increased Abdominal Pressure on the Diaphragm: The bloating and distention from SIBO can affect the function of the diaphragm. If the diaphragm is pushed upwards, it can cause or exacerbate a sliding hiatal hernia, where part of the stomach slides through the diaphragm into the chest cavity.
• Hiatal Hernia: A sliding hiatal hernia occurs when the junction of the esophagus and stomach (the gastroesophageal junction) and a portion of the stomach move above the diaphragm. This can weaken the lower esophageal sphincter, making it easier for stomach acid to reflux into the esophagus, thereby causing GERD.

4. Altered Gut Flora and Inflammation

• Inflammation: SIBO leads to chronic inflammation in the small intestine, which can affect the entire gastrointestinal tract, including the esophagus. Inflammation can compromise the integrity of the lower esophageal sphincter, increasing the risk of acid reflux.
• Gut-Brain Axis: The gut-brain axis, which involves communication between the gut and the central nervous system, can be disrupted in SIBO. This disruption can influence gut motility and function, contributing to both GERD and hiatal hernias.

5. Dysbiosis and Esophageal Sensitivity

• Microbiome Imbalance: SIBO results in dysbiosis, an imbalance in gut bacteria, which can affect the upper gastrointestinal tract. Dysbiosis can lead to increased sensitivity of the esophageal lining, making it more susceptible to acid damage and contributing to GERD symptoms.

Summary

SIBO can contribute to GERD and sliding hiatal hernias through increased intra-abdominal pressure from gas production, impaired gut motility, diaphragm dysfunction, chronic inflammation, and altered gut flora. Managing SIBO through appropriate treatments, such as dietary changes, antibiotics, or herbal antimicrobials, can help reduce these pressures and mitigate the symptoms and risks associated with GERD and sliding hiatal hernias.

Even though SIBO can be a root cause for GERD and hiatal hernias, more severe cases often include additional causes that should be investigated including: musculoskeletal causes, food allergies/ sensitivities, and maldigestion.

Set up an account with Neurovanna to start testing for SIBO in patients with GERD.