Epigenetics, The Microbiome And Breast Milk Flashcards
Epigenetics
Changes that affect how your genes work ie Chang’s in your body reads a dna sequences
EpigeneticsChanges may be a result of behaviours of the environment
It results in genes being turned on or turned Ip or tuned off or turned down
DNA methylation
Works by adding a chemical group to DNA
Typically the group is added to specific places on the DNA where it blocks the rote ins that attach to DNA to read the gene
This chemical group can be removed through a process called demethyltion. Typically methlylation turns genes off and demethylation tuned genes on
Histone modification
Dna wraps around proteins called his tones
DNA wrapped tightly around his tones cannot be accessed by proteins that read the gene This
Some genes are wrapped around the histones and are turned off while some genes are not wrapped around histones and are turned on
Chemical groups can be added or removed from histones and change whether a gene is unwrapped or wrapped
Epigenetics and development
Epigenetics change being before you are born
All cells have the same genes but look and actdiffferently. As you grow and develop, Epigenetics helps determine which function a cell will have for example whether it will become a heart cel, nerve cell or skin cell
Nutrition during pregnancy
Pregnant women environment and behaviour during pregnancy such as wither eats healthy food, can change the baby’s epigenetics. Some of these changes can remain for decades and might make the child more likely to get certain disease.
Infections and Epigenetics
Germs can change your Epigenetics to weaken your immune system. This helps the germ survive
E.g tuberculosis
Infections with tuberculosis germ can cause changes to histones in some of your immune cells that result in turning off the IL-12B gene. Turning off the gene weakens your immune system and improves the survival of the germ.
Gut microbiota and breast milk
Diverse range of microbes living in the gut have the ability to make Epigenetics changes
Breast milk contains a diverse range of microbes which are transferred to the babys gut through breast/breastmilk feeding
Breastmilk also contains obligosaccahrides which are prebiotic they encourage the proliferation of these good microbes
The microbes in breastmilk, particularly bifidobacteria programme the genes in the babys gut to produce IgA which protects against necrotising enterocolitis (nec_ and pathogenic microbes
Some of these changes bacteria present in breastmilk is also responsible for regulating the genetic expression which is responsible for barrier function, digestion and forming blood vessels
Inflammation and breastmilk
Lactoferrin - protein in breastmilk that helps with iron absorption
It’s able to bind to pro infflammatory genes, o turn ff their function
An unbalanced inflammatory response i.e too many pro inflammatory genes switched on is associated with increased rates of NEC and long term inflammatory disorders such as inflammatory bowel disease
Obesity and breastfeeding
Babies who are breastfed are less likely to develop obesity compared with babies who are formula fed
Potentially contributory mechanisms
- less proteins and energy in breastmilk than formula
- breastfeeding behaviour vs bottle feeding behaviour
- regulation of ghrelin ( hunger hormone) and lepton (fullness hormone) - lepton is present in breastmilk
Breastmilk as ore non digestible carbohydrate which encourages growth of bifidobacteria when the gut lacks these microbes there is an increased chance of obesity and related condition developing
High cholesterol in breastmilk turns down the gene responsible for cholesterol production in later life
PPARy2 gene
Associated with increased chance of obesity increased awaits circumference and increased fat deposits
Ala12 allele was associated with higher adiposity indexes in adolescent who had not been breastfed
