TAILIEUCHUNG - The Pathogenesis of Gastrointestinal Bacterial Overgrowth

The normal indigenous intestinal microflora consists of about 1015 bacteria that under physiological conditions reside mainly in the lower gastrointestinal tract. Bacterial overgrowth implies abnormal bacterial colonization of the upper gut, resulting from failure of specific defense mechanisms restricting colonization under physiological conditions. At present two types of bacterial overgrowth with defined pathogenesis can be distinguished: (1) gastric overgrowth with upper respiratory tract microflora resulting from selective failure of the gastric acid barrier, and (2) gastrointestinal overgrowth with Gram-negative bacilli (enteric bacteria) resulting from failure of intestinal clearance | Rifaximin A Poorly Absorbed Antibiotic Pharmacology and Clinical Use Chemotherapy Chemotherapy 2005 51 suppl 1 1-22 DOI 000081988 The Pathogenesis of Gastrointestinal Bacterial Overgrowth Einar Husebye Clinic of Medicine Hospital of Buskerud HF Drammen and Division of Medicine Ullevaal University Hospital of Oslo Oslo Norway Key Words Bacterial overgrowth Pathogenesis Gastrointestinal motility Gastric acid Malabsorption syndromes Abstract The normal indigenous intestinal microflora consists of about 1015 bacteria that under physiological conditions reside mainly in the lower gastrointestinal tract. Bacterial overgrowth implies abnormal bacterial colonization of the upper gut resulting from failure of specific defense mechanisms restricting colonization under physiological conditions. At present two types of bacterial overgrowth with defined pathogenesis can be distinguished 1 gastric overgrowth with upper respiratory tract microflora resulting from selective failure of the gastric acid barrier and 2 gastrointestinal overgrowth with Gram-negative bacilli enteric bacteria resulting from failure of intestinal clearance. Helicobacterpylori-induced gastritis of the oxyntic mucosa is the main cause of acquired failure of the gastric acid barrier which is common among the healthy elderly. Intestinal clearance may fail as the result of impaired intestinal peristalsis or anatomical abnormalities that alter luminal flow. Impaired peristalsis is associated with conditions interfering with intestinal neuromuscular function including myopathic neuropathic autoimmune infectious inflammatory metabolic endocrine and neoplastic diseases. Anatomical ab normalities are mainly the result of gastrointestinal surgery intestinal diverticula or fistula. Combined failure of intestinal clearance and the gastric acid barrier results in more severe colonization with Gram-negative bacilli. Gram-negative bacilli are uncommon in the upper gut of otherwise healthy individuals with gastric

• Y học thường thức
• Bacterial Overgrowth
• Gastric Acid Barrier
• Gastric Microflora
• Gastric Acidity
• Intestinal Microflora
• báo cáo khoa học
• báo cáo y học
• công trình nghiên cứu về y học
• tài liệu về y học
• cách trình bày báo cáo
• BMC Veterinary Research
• Fecal microflora
• Viral infections
• Tumorigenic viral infection
• Infection negative chickens
• COPD and intestinal dysbiosis
• Intestinal dysbiosis
• Chronic obstructive pulmonary
• Secondary immunodeficiency
• Inflammatory process
• Phagitosis activity
• Normal intestinal microflora
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• tài liệu báo cáo khoa học
• báo cáo bệnh thú y
• kiến thức bênh thú y
• nghiên cứu bệnh thú y