Role of microbiota in Affective Disorders Flashcards
How much of our body is microbiome?
Around 1-3% of our body mass
What is a microbiota and microbiome?
Microbiota is the community of microorganisms associated with an environment (Or body area)
Microbiome: Community of microbiome, their environment and their genetics.
What did David Phillip Vetter teach us about microbiomes?
That living in a microbe free world is harmful to the development of a strong immune system.
What is the gut microbiota?
It is the 10 to the power 13 microbes that live in our intestinal tract.
Colonisation starts at birth
Effected by many factors
What are some of the functions of the gut microbiota?
Regulate immune system
contribute to digestive architecture
Protect us from pathogenes
Aid in digestion
Provide nutrients
Metabolize indegestible nutrieints
maintain intestinal barrier
Produce neurotransmitters
When our gut is not fortified by microbiota what can occur?
Leaky gut syndrome leading to IBS and inflammation which can in turn cause mood disorders
What is the gut brain axis?
The complex bi-directional communications between these two areas that transcends:
Endocrine system
Immune system
CNS
Enteric nervous system
How does one study the microbiota between groups?
Via stool samples
Commonly Sequencing the 165 rRNA
Checking for Diversity and Abundance
What has been found with regards to gut microbiota and mood disorders?
Small studies:
Depression:
Decrease diversity in depression
Reduced levels of Bifido and Faecalibactterium
Increased diversity in proinflamatory bacteria in depressed patients
Similar finding for Bi-Polar
What did a meta-analysis find regarding microbiota and mental illness?
59 studies:
No significant difference found other than in Bi-polar
No specific microbiota finding per disorder
In what ways can you study the gut microbiota?
Generally adding something or taking something away
Faecal transplant Probiotic or medicine Infection Germ Free transgenic mice Antibiotics to wipe microbiota
What have the animal studies on the use of probiotics found?
Effects:
Increased stress response
Defictis in social behaviour
Memory and learning deficit
Probiotics can reverse or treat these symptoms
What ways does the Gut brain axis effect mood disorders?
HPA axis can create excess cortisol
Microbiota creates tryptophan
Short Chain Fatty Acids help reduce Pro-inflammatory cytokines
Direct connection of Vagus nerve and the gut via enteric nervous system
In what ways has probiotics been shown to improve mood disorders in animal studies?
1: Reduce HPA-AXIS cortisol abundance
2: Reduce proinflamatory cytokines
3: Help produce tryptophan
4: Encourage BDNF
What is the main intervention to improve gut microbiota?
Dietary intervention:
Reduce processed foods, salt, sugar
Increase fruit, veg and grains as well as omega 3.
Problem: People don’t have motivation to stick to it
