SIBO Pathophysiology

Here are some of the things that can occur within the body from SIBO:

• ​The overgrown bacteria interfere with the normal digestion and absorption of food, and damage the lining of the small intestine (the brush border)
• The bacteria consume some of the food the host eats, causing malabsorption, which over time, can lead to deficiencies in nutrients such as iron and B12, which can cause anemia or chronic low ferritin.[1] [2]
  
• Food unable to be absorbed due to brush border damage is consumed by the bacteria, allowing them to proliferate (overgrow) causing a vicious cycle.[1]
  
• After eating, they produce gas (via fermentation) within the small (or large) intestine, which causes many symptoms, especially abdominal bloating, abdominal pain, constipation, diarrhea or both (the symptoms of IBS).[1]
  
• They can also decrease proper fat absorption (more malabsorption) by deconjugating bile, which can lead to fatty stools (steatorrhea) and deficiencies of fat soluble vitamins A, D and K.[1] [2]
  
• The increased number of bacteria, causes increased endotoxin in the small intestine (bacterial cell wall/LPS) which the immune system can react to, causing: fatigue, body pain, anxiety, depression, and can burden the liver.[3]
  
• The damage to the brush border can create Leaky Gut Syndrome, allowing larger food particles to enter into the body, which the immune system can react to.[1] This can cause food allergies/sensitivities with non-digestive symptoms: headache, nasal mucus, skin rashes, joint pain, etc...
  
• Finally, the bacteria excrete acids which may, in high amounts, lead to neurological and cognitive symptoms, such as brain fog.[4] [5]