The Human Microbiome Flashcards
How does the abundance of phyla change over time?
Changes over time as diversity of species increases throughout the lifetime of an individual
What are the some of the roles of the gut microbiome in the body
Protects against pathogens
Synthesis of vitamins
Immune system development
Promotion of intestinal angiogenesis
Promotion of fat storage
Short chain fatty acid production by fermentation of dietary fibre
Modulation of CNS
What is dysbiosis
Imbalance of the normal gut microbiome composition which causes harm
Definition of prebiotics
Non digestible ingredient that is beneficial to the growth of 1 or more types of bacteria. Improves hosts health
Definition of probiotics
Living non-pathogenic organisms used as food to benefit hosts health
Characteristics of clostridium difficile
Gram positive
Anaerobic
Spore former
Spread by fecal oral route
Commensals are involved in which processes
Development and stimulation of the immune system
Preventing colonisation of pathogens by competing with them
By producing beneficial nutrients eg vitamin K
Metabolism ( transformation reactions, metabolism of therapeutic drugs and xenobiotic substances)
How do commensals prevent colonisation of the gut (direct and indirect)
Direct = nutrient competition and direct toxicity by releasing bacteriocins
Indirect = production of metabolic products such as SCFA and bile salts (prevents growth of bacteria)
Induces immune response by releasing defensins
Factors that affects the microbiome
Age
Environment
Host genetics
Diet
Lifestyle
Immune response
Microbial co-adaptation
Cytokines associate with Hyperimmunity
IL-6
IL-12
TNF
Cytokines associated with immunodeficiency
NOD2 gene that codes for pro-inflammatory mediators
IL-10
