The skin, mouth, nose, conjunctiva, throat, colon, vagina and urethra surfaces are colonized by aerobic and anaerobic bacteria.
Also ref2242ed to as microbiota.
A limited number of transient bacteria may involve the trachea, bronchi, esophagus, stomach and upper urinary tract, but these sites are usually not colonized by indigenous microflora.
Estimated total number of colonizing microbes is 10 to the 14th power in humans.
Microbiota provide genomic material with 100 times as many genes as our own genome.
The microbiota exerts is effects locally and systemically.
Dietary components from vegetables interact with intestinal immune receptors and regulate the organogenesis of lymphoid follicles, intestinal immunity and the microbiota.
Bacteria number and variety increase exponentially in the proximal and distal GI tract.
The large intestine arm is most of the gastrointestinal microbiota.
99% of the microbial mass in the human body is found within the gastrointestinal tract.
After only 10 days of treatment with systemic antibiotics, the gut microbiota can be altered for up to 1 year.
By 1-2 years the intestinal epithelium and the intestinal mucosal barrier that it secretes have co-developed in a way that is tolerant to, and even supportive of, the gut flora and that also provides a barrier to pathogenic organisms.
Advances in genomic sequencing allows for the sequencing of the DNA of cells and can identify a bacterial profile based on DNA formation.
Distinct microbiomes can be identified of different organs within the body, as well as differences between the microbiomes of indiviuals.
Long-term use of nonsteroidal anti-inflammatory drugs and PPIs disturbs the intestinal microbiota and frequently causes intestinal mucosal injury.
Disturbances between the interplay between bacteria and the host at the mucosal level in the gut affect the gut-liver axis and contribute to low-grade inflammation, metabolic endotoxemia, obesity, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis and some malignancies.
The nascent gut microbiota of infants is essential in establishing proper immune function and that disruptions to this community results in early dysfunction and subsequent development of asthma.
Use of broad-spectrum antibiotics can disrupt gut microbiota and is an independent risk factor for transplant related mortality after allogeneic stem cell transplant.
Poor oral hygiene, as with peridontal disease, is related to increased risk of upper gastrointestinal cancers.
The oral pathogens Porphyromonas gingivalis and Aggregatibacter actinomyccetemcomitans are associated with an increased risk of pancreastic cancer, while an abundance of Fusobacteria and its genus Leptotrichia are associated with decreased risk.
Carrying Neisseria in abundance in the oral cavity associated with a lower incidence of head and neck canccer.
Neisseria found in lower concentrations in the mouth of smokers, suggesting a link to cancers.
Fusobacterium nucleatum, normally found in the mouth and is associated with periodontal disease and is often present in colorectal cancer, and is related to an increased risk.
Patients with a high microbiota metabotype have an elevated risk for irinotecan dependent adverse drug responses.
Higher gut microbial diversity is associated with improved survival in patients undergoing hematopoetic poetic stem cell transplantation.