Week 1: Human Microbiome Flashcards
(39 cards)
1
Q
Microbe
3 bullet points
A
- Small, metabolically, genetically and structurally diverse organisms
- Some can live anywhere
- Essential for human health
2
Q
Microbes influence___
3 bullet points
A
- genetic diversity
- normal physiology
- health state
3
Q
What is a microbiome?
3 bullet points
definition, types(4), where on spectrum
A
- the microbial communities of an environment
- Bacteria ・viruses・fungi・archaea
- ← beneficial・commensal・pathogenic →
4
Q
Where do these microbes live? Give examples of specific niches.
A
- in biomes, specific conditions(temp., moisture) and characteristic organisms
- each biome has different microbes
Ex: skin, mouth, armpit, stomach, intestines and vagina
5
Q
Describe skin biome
A
desert, dry and high UV
6
Q
Describe mouth biome
A
lake, wet, nutrient rich
7
Q
Describe armpit biome
A
rain forest, moist, warm, humid
8
Q
Describe stomach biome
A
acid lake
9
Q
Describe intestine, vagina biomes
A
swamps
10
Q
Which microbes live where?
What determines where microbes live on/in humans?
A
ecological principles
11
Q
Name ecological principles(4)
A
- selection/site specificity
- succession
- niche filling/founders effect
- disturbance events(cyclic[diurnal, seasonal], catastrophic)
12
Q
Selection/site specificity
A
- diff. microbes have diff. needs
- diff. sites host diff microbes due to variation in: moisture, pH, nutrients, presence of other microbes
13
Q
Selection/site specificity:
How to characterize microbial environments? w/ examples
A
- abiotic: non-living factor of an ecosystem
ex: temp., pH, moisture, nutrients, light, oxygen - biotic: living factor of an ecosystem
ex: host immunology, microbial interaction
14
Q
selection/site specificity:
microbes change their environments due to___
A
- Due to metabolic “waste” product
ex: pH・oxygen・sugars・etc - Due to ability to kill other microbes
ex: Secrete toxins, antibiotics, antifungals, lyse, etc.
15
Q
Niche filling/Founders effect:
Unique microbiome for each person acquired___
A
- Acquired each generation: birth, foods, environment
- “microbial signature”
16
Q
Niche filling/Founders effect:
in utero___
A
- babies have limited/no bacteria within the amniotic sac
17
Q
Niche filling/Founders effect:
Baby has limited___
A
- habitat space
- nutrients
this is where niche filling and founder effect come in
18
Q
Founders effect
A
- Those species that get there first, fill specific spaces
- Harder to remove once established
- Redecorate- change the habitat
19
Q
Niche filling:
Baby as “bacterial magnet”:
A
- Open habitats for microbes to colonize
- Repressed immune system
- Surrounded by microbes(moms, other, environment)
20
Q
Niche filling during:
A
- during labor when water breaks, vaginal microbes
- during delivery; vaginally(vaginal and gut microbes) or scheduled C-section(skin microbes)
- w/ first foods(skin, breast milk, formula)
- skin to skin interactions(kangaroo, kissing, nursing)
21
Q
Succession
A
- the process by which the structure of a biological community evolves over time
22
Q
Baby primary succession
A
- niche colonized for the first time
- birth-2/3 years
23
Q
secondary succession
A
- recolonization of niche after major disturbance
24
Q
Succession occurring through___
A
- Immune system development
- Foods
- Environmental influences(medicine, pathogens, daily exposures-soaps,etc.)
25
What is the function of the microbiome?
| 7 bullet points
- Trains the immune system
- Fills niches to keep out pathogens
- Digests food
- Synthesizing vitamins
- Detoxifies poisons/metabolizes drugs
- Polyphenols degraded to antioxidants
- Mental health
26
How stable is the microbiome?
Transition to solid food
3 bullet points
- w/ table foods, bacteroidetes increased
- More similar to adult microbiome
- Adult microbiome influenced by diet
27
How stable is the microbiome?
| Relative stability over time in gut
- 37 healthy adults
- 60% of strains remaining during 5 years
- Strains were maintained within family units, but not unrelated people
- Early gut colonizers most stable
28
Disturbance events:
Ecosystem problems if___ causes disturbance
3 bullet points
- Key organisms missing
- Wrong nutrients
- Invasive species
29
Cyclic Disturbance:
| Diet Shift
-Drastic short term diet shifts changes microbiome community structure
30
Cyclic Disturbance: Diet Shift
| Meat + cheese increases_____
-Increase in bile tolerant microbes that can trigger inflammatory bowel disease
31
Cyclic Disturbance: Diet Shift
| Vegetarian
-Increase in plant polysaccharide degraders
32
Cyclic Disturbance: Diet Shift
| Bacteria acquired from food were___
-transient
33
Catastrophic Disturbance: Antibiotics
Antibiotics cause___
4 bullet points
- Shift in bacterial taxa
- Open habitat
- Resistant taxa increase
- Opportunistic pathogens in low abundance in healthy humans
34
Catastrophic Disturbance: Digestive system distress
| 4 types of Chronic digestive system disorders
- Inflammatory bowel disease
- Crohn's disease
- Ulcerative colitis
- Clostridium difficile infections
35
Catastrophic Disturbance: Digestive system distress
digestive system distress causes
2 bullet points
- Microbiome profile to be different from healthy people
| - Chronic diarrhea
36
digestive system distress caused by
Often begins after antibiotic use for an unrelated issue(pneumonia, surgery, etc..)
37
C. difficile case study
- 61 yo F
- Chronic diarrhea every 15 mins for 8 months
- Confined to wheelchair
- Antibiotics for back surgery
- Repeated cycles of antibiotics, symptom remission, then resurgence
- treated w/ FMT and 1 month negative for C. difficile
38
Fetal Microbiome Treatment
| 4 bullet points
- 4th century, China; treatment for food poisoning or severe diarrhea
- used to reestablish microbiome using the healthy microbiome from another individual, often family member
- screened stool and blood for: known pathogens, Chronic conditions(metabolic syndrome, autoimmune disorders, digestive problems
- also successful for ulcerative colitis, Crohn’s disease, and inflammatory bowel disease
39
Fetal Microbiome Treatment
Methods
- Duodenal infusion
- Colonoscopy; most effective
- Enema
- Oral capsules
