Microbiome Flashcards
what are the types of microbes in a microbiome?
Bacteria
Archaea
Fungi
Viruses
MOST important microbiome?
gastrointestinal tract
Important microbiomes?
Vaginal
Respiratory Track
Skin
What body parts are sterile?
Blood
CSF
Deep Tissues
What body parts are nearly sterile?
Bronchi, alveoli
Esophagus
Urinary bladder
Uterus
What is holobiont?
individual species such as human, plant, and animals.
It is the host and its microbiota.
What is hologenome?
combined genome of bionts
Main functions of bacteria in gut?
Protects against epithelial injury
Develops and trains immune system
provides Immunological equilibrium
Converts dietary fibers into SCFA
What is dysbiosis?
Has decreased richness(diversity). It’s an unhealthy microbiome where specific beneficial functions are missing or detrimental functions are added. “the song is off key”
What is a healthy microbiome?
characterized by richness (diversity)
Dietary fibers are?
used by intestinal bacteria
SCFA (short chain fatty acids)
energy source for gut cells & gut health
SCFA are acetate propionate and butyrate
What does the microbiome play a significant role in?
human phenotypes. human phenotypes can be transferred to humans or mice by microbiota which can alter their phenotype.
what is polymicrobial?
caused by several types of microorganisms. aerobes/anaerobes; mostly anaerobes
what does dysbiosis promote?
promotes GI carcinogensis via inflammation and DNA damage by bacterial toxins
How is systemic trimethylamine oxide (TMAO) increased?
By chronic consumption of red meat
High levels of TMAO leads to?
Greater risk of heart attack
besides SCFA what else do gut microbiota produce?
antimicrobials
hormones and neuroactive chemicals
immune priming and neuronal signaling
woese classification of cultured taxa by rRNA?
16S rRNA
what is 16S rRNA?
the key gene for determining microbiome composition (bacterial diversity and abundance)
where do we get our microbiome?
from birth our gut microbiome is similar to the mothers vaginal microbiome or skin microbiome if born cesarean
microbiome forms as we begin to ingest food such as breastmilk
clostridiodes difficile (C. diff)
gram + bacillus, anaerobe
spores survive gastric acid and germinate in small intestine
makes toxins TcdA and TcdB (toxins A and B)
how do you treat c.diff?
change or stop use of antibiotics; if persistent use fecal microbiota transplant
what is B. fragilis?
gram - obligate anaerobe with capsule and beta-lactam resistant
what is Fusobacterium?
gram - rod shape with pointy ends
what is treponema denticola?
gram - spirochete
