Flashcards in Normal Flora Deck (17):
The human microbiome and human genome have how many genes?
Human microbiome has 1,000,000+
Human genome has 30,000
What does commenalism mean?
The microbe benefits with no harm to the host
What is colonization?
The microbe "moves in" to the host without causing disease
What is a carrier (reservoir) state?
Colonization with the potential for transmission to other people
In a mutualistic relationship, what are the three ways that the microbe benefits from a host?
Nutrient supply form consumed food and products from other bacteria
Variety of ecological niches to occupy
Complex but stable environment
Does the microbiome benefit its host by stimulating the immune system?
The microbiome benefits its host by promoting what?
Epithelial cell proliferation and differentiation
The microbiome benefits its host by degrading harmful compounds produced by what?
Other bacteria in the microbiome
The microbiome benefits its host by the production of what?
Essential nutrients for microbes, such as vitamins K and B12
Does the microbiome compete/interfere with pathogens?
Immune defects in germ-free mice include what? 5 things
Immature lymphoid follicles and small Peyer's patches
Reduced production of mucosal IgA
Reduced production of antimicrobial peptides
Reduced CD8+ intestinal epithelial cells and CD4+ T cells
Increased susceptibility to infection by enteric pathogens
What one potential benefit was seen in germ-free mice?
Lower body mass and fat composition
What is dysbiosis?
Perturbed balance within the microbiome (mainly intestinal) leading to aberrant immune responses and inflammation
What is a prebiotic?
Ingredients in food that remain undigested, and which may stimulate either the growth or the activity of bacteria that are also beneficial to human health
What is a synbiotic?
Combination of probiotic and prebiotic
Can normal flora be pathogenic? If so, when?
Yes if physical or immune defenses are breached