Normal Microflora

The intestinal microflora of healthy humans is comprised of more than 400 species of bacteria with a population of 1012-1014 colony-forming units (CFU) per gram, of which more than 98% are resident in the colon. This bacterial population nearly exceeds the population of cells in the human body. The microflora is composed of both aerobic and predominantly anaerobic microorganisms that when equilibrium within an individual is maintained confer nutritional and immune benefits. A prime example of the importance of microorganisms in the GI tract was the study of gnotobiotic (germfree) mice, which suffered persistent enteritis and severe infections with poor survival rate. Through the interaction of the mucosal surface with the GI tract microflora an important system of immune defense is established.

The presence of microorganisms in different segments of the GI tract varies both qualitatively and quantitatively. Bacteria from the mouth are predominantly anaerobes including streptococci, Bacteroides, Lactobacillus, and some yeasts; these wash down to the stomach with the intake of food and function of swallowing. In the stomach the acid environment destroys most of the oral and food-ingested microorganisms. The microflora of the stomach is comprised of mostly Gram-positive and aerobic microflora at very low levels (103 CFUml-1). Peptostreptococcus, Fusobacterium, and Bacteroides species are present in low numbers while Clostridium is uncommon.

The volume of microflora increases exponentially from the small intestine, which is sparsely colonized, to the richly populated colon. The concentrations of bacteria found in the small intestine are between 103 and 104CFUmT\ again both facultative anaerobes and aerobic bacteria with almost complete absence of coliforms and Bacteriodes.

The microflora of the colon dramatically increases to a concentration of 1011-1012CFUgm~1. This bacterial load accounts for up to 50% of the volume of colonic content. Although the colonic microflora comprises more than 400 different species it is predominantly anaerobic including Bacteroides, Fusobacterium, Bifidobacterium, Lactobacillus, Enterobacter and coliforms, and other facultative anaerobes (Staphlococcus and Candida species).

All Natural Yeast Infection Treatment

All Natural Yeast Infection Treatment

Ever have a yeast infection? The raw, itchy and outright unbearable burning sensation that always comes with even the mildest infection can wreak such havoc on our daily lives.

Get My Free Ebook

Post a comment