Current views on the etiopathogenesis, clinical manifestation, diagnostics, treatment and correlation with other nosological entities of SIBO

Small intestinal bacterial overgrowth (SIBO) is a disease of great clinical and socioeconomic importance caused by an excessive amount of bacteria in the upper alimentary tract. Physiological microbiota are replaced by pathogenic bacteria mainly from large intestine, which is called dysbacteriosis. SIBO disturbs digestion and absorption in the alimentary tract, which seems to cause inflammation. SIBO affects the morphology and function of the digestive system and causes systemic complications (e.g. osteoporosis, macrocytic anemia). Inflammation interferes with gene expression responsible for producing and secreting mucus, therefore, a correlation between SIBO and cystic fibrosis, irritable bowel syndrome and chronic abdominal pain are postulated. All conditions leading to bacterial growth such as congenital and anatomical abnormalities in the digestive tract, motility disorder or immunological deficits are risk factors of SIBO. A typical clinical manifestation of SIBO comprises meteorism, enterectasia, abdominal discomfort and diarrhea. Diagnostic procedures such as glucose, lactulose, methane, 13C mixed triglyceride breath tests are being used in diagnosing SIBO.