Food Poisoning & Medically Induced Causes
Food poisoning is a major but often overlooked trigger for SIBO. When harmful bacteria that cause food poisoning (including E. coli or Salmonella) release toxins, they can damage the migrating motor complex (MMC)—the system responsible for clearing bacteria from the small intestine. If this function is impaired, bacteria accumulate and cause long-term digestive issues. Additionally, some medications can alter gut motility or microbiome balance, further increasing the risk.
Food Poisoning - A bacterial infection from contaminated food or water can cause long-lasting damage to gut nerves, impairing motility and leading to chronic bacterial overgrowth in some individuals.
Antibiotic Use – Broad-spectrum antibiotics disrupt the gut microbiome by killing beneficial bacteria, sometimes allowing harmful bacteria to take over.
Opioid Use – Opioids slow gut motility, causing food and bacteria to stagnate in the small intestine, which creates an ideal environment for bacterial overgrowth.
Gastrointestinal & Systemic Diseases
Crohn’s Disease – A type of inflammatory bowel disease (IBD) that causes scarring and strictures, reducing intestinal motility and allowing bacterial buildup.
Irritable Bowel Syndrome (IBS) – A functional gut disorder associated with altered motility and gut-brain communication, making individuals more prone to SIBO.
Celiac Disease – An autoimmune reaction to gluten that damages the small intestine’s lining, reducing its ability to clear excess bacteria.
Non-Alcoholic Fatty Liver Disease (NAFLD) – A metabolic liver disorder that can alter bile production, affecting digestion and bacterial regulation.
Cirrhosis – A severe liver disease that weakens the gut’s ability to clear bacteria, increasing the likelihood of overgrowth.
Pancreatic Insufficiency – A condition where the pancreas does not produce enough enzymes, causing malabsorption and allowing bacteria to proliferate.
Diabetes – Chronically high blood sugar levels can damage nerves in the gut, leading to a sluggish digestive system and bacterial overgrowth.
Hypothyroidism – An underactive thyroid slows metabolism and gut motility, creating an environment where bacteria can overgrow.
Parkinson’s Disease – A neurodegenerative disorder that affects the gut’s nerve function, leading to sluggish motility.
Systemic Sclerosis (Scleroderma) – An autoimmune disease that stiffens connective tissues, impairing intestinal movement.
Pseudo-Obstruction – A condition that mimics a bowel blockage due to nerve or muscle dysfunction, preventing proper intestinal clearance.
Human Immunodeficiency Virus (HIV) – A viral infection that weakens the immune system, increasing susceptibility to bacterial imbalances.
Several diseases can impair digestion, motility, or immune function, making it easier for bacteria to overcolonize the small intestine. Chronic inflammation, damage to the intestinal lining, or metabolic disorders can all contribute to SIBO by disrupting the normal balance of gut bacteria.
Structural Abnormalities & Surgical Causes
The physical structure of the gastrointestinal (GI) tract plays a crucial role in maintaining proper digestion and bacterial balance. Structural changes—whether congenital, disease-related, or caused by surgery—can slow motility, allowing bacteria to accumulate in the small intestine.
Gastric Bypass – A surgical weight-loss procedure that alters the digestive tract’s natural flow, slowing movement and allowing bacteria to multiply.
Abdominal Surgery – Past surgeries in the abdominal region can lead to scar tissue, which may obstruct the intestines and slow food movement.
Small Bowel Tumor – Any growth in the small intestine can create a physical obstruction, trapping bacteria and promoting overgrowth.
Small Bowel Diverticula – Pouch-like formations in the small intestine that can trap food and bacteria, leading to stagnant overgrowth.
Intestinal Strictures – Narrowed sections of the intestine (common in Crohn’s disease) that slow digestion and create an environment for bacterial buildup.