L1 Normal flora Flashcards
What does schooling of the immune system mean?
Various immune cells are generated and trained to identify and eliminate pathogens. The process begins in the bone marrow where immune cells are produced. The cells will then travel to various organs where they mature and undergo further training.
Symbiosis can be mutualistic, commensalistic, or parasitic. Describe each one.
Mutualism: both organisms benefit
Commensalism: one benefits and the other is unaffected.
Parasitic: one benefits thereby harming the other.
What are the different barriers in the body?
Skin (epithelial cells): junctions that form barriers (protein structure keeps cell layer nonpermeable), impermeable to water, oily: pathogen and water resistant, antimicrobial peptides.
Mucous membranes: mucus secretion, soluble molecules: lysozyme; cleave cell wall of bacteria.
Stomach acid low pH, enzymes
Urinary tract: flush of urine
Eyes: tears
Blood-brain barrier after invasion has occurred, neuronal system.
What is the role of the microbiome?
The gut microbiome is the most diverse in the body!
Metabolic products can be used by our bodies (neurotransmitters synthesis supported by gut bacteria)
- vitamins produced by microbiomes, fermentation of non-digestible fibers, and energy production.
Protection against invading pathogens
- antimicrobial effect (production of antimicrobial peptides).
Schooling of the immune system
Mention important information about the gut microbiome.
More than 200 common species (100 less common ones)
Large source for metabolites: small molecules that are produced as a result of metabiólism, the biochemical process that occurs in cells to sustain life
Strict anaerobes: do not need oxygen for respiration to occur (obligate/facultative)
What is the difference between obligate and facultative?
Obligate anaerobes: microorganisms unable to survive in the presence of oxygen. They lack the enzymes necessary to neutralize toxic byproducts of oxygen metabolism.
Facultative: microorganisms that can survive in both oxygen-rich and oxygen-poor environments. They are able to switch between aerobic and anaerobic metabolism, depending on the availability of oxygen
What bacteria can be found in the gut microbiome?
Enterococci: gram-positive, cocci-shaped bacteria that are facultative anaerobes.
Bacteroides: gram-negative, non-spore-forming, obligately anaerobic, rod-shaped bacteria.
Lactobacilli: gram-positive, catalase-negative, non-spore-forming, rod-shaped bacteria that produce lactic acid as the major end product of fermentation.
Clostridia: strictly anaerobic to aerotolerant spore-forming bacilli found in soil as well as in normal intestinal flora.
What factors can influence the composition of gut flora?
Diet: substrate adapted to ferment bacteria, not healthy food: gut will have less diverse flora!
Chemicals
Drugs
Antibiotics: wash away good bacteria too
Environment microbe exposure: healthy person automation of which microbes are wanted and ones that need to be killed/excreted.
