The normal steady movement of intestinal contents (peristalsis) is important to help maintain a proper balance of bacteria in the small intestine. Conditions in which intestinal contents slow or pool in one place allow excess bacteria to grow.
The excess bacteria consume nutrients, including carbohydrates and vitamin B12, leading to lower calorie intake and vitamin B12 deficiency. The bacteria also split bile salts, which are secreted by the liver to aid digestion. The loss of bile salts causes difficulty absorbing fats, leading to diarrhea and poor nutrition.
Symptoms of SIBO include bloating, diarrhea, fatigue, abdominal distension, abdominal pain or discomfort and low energy. The frequency and severity of symptoms likely reflect both the degree of bacterial overgrowth along with the extent of inflammation within the mucosal lining.
