Emma
Articulate an argument for not using triclosan-containing soaps and other consumer products.
Becomes an environmental contaminant
People exposed to triclosan, show more resistance to other antibiotics
Opposite effects for what it was originally intended for
What are three benefits that the gut microbiota provides for a human host?
Breakdown of otherwise indigestible food structures
Production of compounds that promote immune system development/health
Glucose Homeostasis
When does our microbiome transition from the infant-type microbiome to the adult-type microbiome?
Ages 1-2
How could you test the effect of a particular host gene on the gut microbiota?
Mouse Model: make a knockout of the gene and see if the microbiota were changed.
What are 2 weaknesses of 16S rDNA sequencing for assessing a bacterial population?
Doesn’t distinguish between live and dead cells
Doesn’t tell you anything about the functions
Name an antimicrobial compound that until recently was a popular ingredient in consumer products labeled “antimicrobial” but is now not generally regarded as safe by FDA.
Triclosan
What strategies might future interventions employ to stabilize and restore the human gut microbiome in a person?
Specific Diets
Probiotic use
FMT
How do we initially get our gut microbiome?
Inoculated from our mothers and the early foods we eat
Is the gut microbiota relatively insensitive to conditions, or does it respond quickly to changing conditions?
Responds Quickly to changing conditions
In 16S rDNA sequencing, how do we estimate the abundance of a bacterial species in the original sample?
Assume the abundance of the species from the original sample is proportional to the abundance of the DNA in the DNA sample
How would a rapid antibiotic-susceptibility test improve antibiotic stewardship and also lower costs at the clinic?
Doctors could prescribe the right antibiotic for the infection rather than empirically trying one after the other until finding the right one.
Less doctors visit
Less antibiotics
Saves time and money
Given the importance of the early microbiome, what is one practical way that parents can try to guard against harmful alterations to their child’s microbiome?
Conservative about Antibiotics
Lookout to restore microbiome
Name two changes in host factors/behavior that impact that microbiota such that it can change a host phenotype when transplanted.
Changes in diet
Changes in Circadian Rhythms
Name 5 factors that interact with the human gut microbiota either unidirectionally or bidirectionally.
Diet
Exercise
Age
Stress
Hormones
Adipose Tissue
Fat Tissue
Host Genetics
Inflammation
Liver Parameters
Immune system
Jet Lag
Why is 16S rDNA sequencing a good way to assess what kinds of bacteria are present in a sample?
Genes have some regions that are the same in all cells, and some different from taxon to taxon. Amplify all using universal and define who is there in variable sequences.
About how many courses of antibiotics are prescribed in the United States each year (to the nearest 10 million)?
260-270 million
When is our gut microbiome most important for future health?
During first 2 years of life
How is a fecal microbiotal transplant (FMT) achieved?
Mix Feces with sterile buffer
Filter to remove any undigested food structures
Take purified bacteria and administer to recipient
Name two diseases that are associated with substantial changes to the human microbiome.
IBD
Type II Diabetes
What is the difference between a push incentive and a pull incentive for new antibiotic development?
Push---> Facilitate early research and pre-clinical trials
Pull---> Facilitate clinical trials, bringing a drug to market, and protecting revenue streams of the drug
About how many antibiotic-resistant bacterial infections occur in the United States each year? How many deaths from such infections?
2.7-2.8 million infections
30,000 deaths
What is the “bacterial baptism” hypothesis, what practice has it led to, and why is it contested?
We obtain our microbiome from our mothers during vaginal birth
Led to Vaginal Seeding
We do not fully understand if the bacteria is super important
How could you test whether a particular microbiotal composition can affect a host phenotype?
Transfer microbiota into germ free mouse and access the phenotype once the microbiota takes residence in the mouse
What are the 6 bacterial phyla that can be present in the human microbiota? What are some characteristics of each? What two phyla dominate in healthy individuals?
Dominate
Firmicutes (Gram Positive)
Bacterial Deedee's (Gram Neg)
Other 4 Phyla
Proteobacteria (Gram Neg)
Actinobacteria (Gram Positive)
Verrucomicrobia (Gram Neg)
Fusobacteria (Gram Neg)
Why is the use of antibiotics in animals “to prevent disease” controversial?
Hard to distinguish between prevention and growth promotion.