L13-14 Human Microbiome + Timor

Question 1

Define microbiome

Answer 1

sum total of the genes carried by micro-organisms commensal with humans (genetic constitution reflects phenotype)

Question 2

define microbiota

Answer 2

species of micro-organisms commensal with humans (species themselves, changes in species little effect whole microbiome)

Question 3

what does the diversity of the microbiome mean

Answer 3

number and abundance distribution of distinct types of organisms

Question 4

what is alpha and beta diversity

Answer 4

• Alpha diversity (within sample)

* Beta diversity (between samples from same habitat in different subjects)

Question 5

what can be used to analyse the microbiome

Answer 5

sample > nucleic acid extraction > 16S rRNA sequencing

Question 6

what is PC1 and PC2

Answer 6

• 1: vector in data that captures diversity in certain singular planes
o PC1 therefore: further apart on axis = most distinct
o PC2 axis: next distinct

Question 7

how can the variation in microbiota but microbiome similar

Answer 7

o Function of evolutionary conserved genes similar

o Functional microbiome constant

Question 8

how does the human microbiome change over time

Answer 8

1. evolutionary change (colonisation, recruitment, competition)
selection pressures (diet, antibiotics)
variation- similar micriobmiome but diff microbiota

Question 9

what does antibiotics do to microbiome

Answer 9

alters population structure
reduces bacterial diversity
redisibtrues composition

Question 10

sanitation effect on alpha and beta diversity

Answer 10

inc. b

dec. a

Question 11

cesarean, globalisation effect on alpha and beta diversity

Answer 11

inc. b

dec. a

Question 12

why could illness be a reason for poor growth in timor

Answer 12

• Immune response is energetically costly and competes with growth for available energy (McDade 2003) = shift in growth to immune system
o – activation increases metabolic costs
o – illness associated with decreased appetite & impaired nutrient absorption

Question 13

why could nutrition be a reason for poor growth in timor

Answer 13

• Hypothesis: Low energy intake and macro/micro-nutrient deficiencies can cause growth deficits
o children don’t reach genetic potential for growth

Question 14

how to eliminate genetic cause for poor growth in timor

Answer 14

admixture= no difference between language areas

Question 15

describe maternal malnutrition on child growth in timor

Answer 15

• (fluctuating food availability: maternal food restriction has lasting effect on child phenotype

Question 16

why does late stage of gestation food shortage = increase bmi

Answer 16

when breast fed + have higher nutritional uptake= better able to store and capture as body fat // heavier