Distribution and composition of bacterial species in the gastrointestinal tract

Range Figure link - link CFU/mL
Organism Human Homo sapiens
Reference Dueñas M et al., Studies on Modulation of Gut Microbiota by Wine Polyphenols: From Isolated Cultures to Omic Approaches. Antioxidants (Basel). 2015 Jan 5 4(1):1-21. doi: 10.3390/antiox4010001. p.6 figure 2PubMed ID26785335
Primary Source See refs beneath figure
Comments P.5 2nd paragraph: "Among the human gastrointestinal microbiota, the majority of the species belong to the phyla Firmicutes, Bacteroides, Actinobacteria and Proteobacteria [primary source 26] (Figure 2). The phylogenetic composition of the gut microbiota is considered specific and stable over time for each individual. The species vary greatly between individuals. In fact, interindividual variation in gut microbiota may, in part, reflect differences in dietary intake, although the response of the gut microbiota to dietary change can also differ among individuals. The composition of the individual’s microbiota can fluctuate under some circumstances, for instance acute diarrheal illnesses, antibiotic treatment, or to a lesser extent when being induced by dietary interventions, but the individual flora composition patterns usually remain constant [primary source 27]. Among the microbiota associated with the esophagus, are included microorganisms belonging to the genera Streptococcus, Prevotella and Veillonella, which also appear in the oral cavity. The density of colonization is increased about eight times from proximal regions of the small intestine (10^3 bacterias/g) until the colon. In the stomach and duodenum, the number of microorganisms is reduced due to acid, bile and pancreatic secretions as advances in the small intestine, the acidity decreases due to the dilution of the acid, which facilitates bacterial colonization, reaching 10^11 CFU (colony forming units)/mL in the colon. The most frequently found bacteria in this area are members of the genus Bacteroides, Bifidobacterium, Eubacterium, Clostridium, Lactobacillus, and Gram-positive cocci [primary source 28], while Enterococci and representatives of the Enterobacteriaceae family are found to a lesser extent [primary source 29]." See Macpherson & Harris 2004, PMID 15173836, p.478 box 1 'Intestinal microorganisms' link See BNID 108289
Entered by Uri M
ID 112858