The human microbiome Flashcards
1
Q
Aspects which impact on the human microbiome
A
- Age: microbiome develops alongside age
- Diet: Big involvement. It adapts to your diet
- Genetics: Determines what receptors we have and if we secrete certain metabolites that can interact at a metabolic level with the microbiome
- Lifestyle: Sedentary or active will affect microbiome
- Environment
- Immune response: tuned exposure and how it was developed will affect microbiome development
- Microbial co-adaptation: Having a lot of one species, the microbiome will adapt so they can live together compared to another species which are scarce to me
2
Q
How does the microbiome play a role in control of homeostatic mechanisms in the body
A
- Protection against pathogens
- Synthesis of vitamins: the microbiome can synthesise Vit K and B12 for us to take up
- Immune system development
- Promotion of intestinal angiogenesis
- Promotion of fat storage
- Short chain fatty acid production by fermentation of dietary fibre: microbes can help digest this fibre, ferment it and give rise to SCFA
- Modulation of CNS
3
Q
How can the microbiome prevent a pathogen from being successful. Direct and indirect mechanisms
A
- Direct mechanisms:
- Nutrient competition: microbiota take up nutrients so the pathogens struggle to establish itself. Compete for salicylic acid, fructose.
- Direct toxicity: strategies to kill incoming bacteria. Biofilm, bacteriocin and type IV secretion - Indirect mechanism
- Immune induction: commensals help the immune system to be optimally prime to deal with a pathogen
- Metabolic products: Sort of links to direct toxicity, refers to metabolising certain host factors such as bile salts, this change impacts certain bacteria as they miss certain triggers and certain nurtrients
4
Q
Define the terms dysbiosis, probiotics and prebiotics
A
- Dysbiosis: Imbalance of normal gut microbiota composition. Quantitative/qualitative, metabolism etc… These changes result in harmful effects on the host
- Probiotics: Non-living organisms used as food ingredients to benefit the hosts’ health
- Prebiotics: Non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improving the hosts’ health.