Disease Causing Microbiota

Bacteria closely associated, and attached to the epithelium like Helicobacter pylori, may be sampled from gastric contents with difficulty (29). H. pylori is a Gram-negative bacterium that resides below the mucous layer next to the gastric epithelium. H. pylori is rarely found before age 10 but increases to 10% in those between 18 and 30 years of age, and to 50% in those older than age 60 (35). In developing nations the majority of children are infected before age 10, and adult prevalence peaks at more than 80% before age 50. Thus H. pylori infection ranges depend on age and socioeconomic differences (36). H. pylori produces urease, an enzyme that breaks down urea into ammonium and bicarbonate. Ammonium provides an alkaline environment, which helps the bacterium protect itself from gastric acid injury. Most infected subjects do not have symptoms of H. pylori infection. However, H. pylori may induce acute gastritis with symptoms such as epigastric pain, bloating, nausea and vomiting, and/or chronic gastritis. Furthermore, it may also be associated with ulcer disease and gastric carcinomas.

Other gastric bacteria besides Helicobacter species only become apparent in patients with reduced acidity (achlorhydria). Achlorhydria may occur in elderly persons (37). Colonization of the gastric lumen may occur in patients on anti-secretory medication meant to reduce gastric acid secretion. Many subjects regularly use these anti-secretory drugs. Acid suppression may allow bacteria to survive in the stomach which results in gastric bacterial overgrowth with the degree of overgrowth depending upon the elevation of the pH (20). Infectious gastritis is more rarely caused by Mycobacterium tuberculosis, Mycobacterium avium, Actinomyces israellii, and Treponema pallidum (3).

Pregnancy And Childbirth

Pregnancy And Childbirth

If Pregnancy Is Something That Frightens You, It's Time To Convert Your Fear Into Joy. Ready To Give Birth To A Child? Is The New Status Hitting Your State Of Mind? Are You Still Scared To Undergo All The Pain That Your Best Friend Underwent Just A Few Days Back? Not Convinced With The Answers Given By The Experts?

Get My Free Ebook


Post a comment