Microbiome in Health

zijimubo1's version from 2016-12-15 08:10

Section 1

Question Answer
List the majority of body sites that are colonized by resident commensal microorganisms.Nasal passages, mouth, skin, gut, urogenital.
Microbe found in respiratory tract. (3)1) staph epidermidis - forms bio films in lining of nose;
2) Corynebacteria - associated with Upper Respiratory Tract;
3) Candida fungi
Microbe found in mouth. (2)1) fusobacteria - oral biofilm;
2) strep mutans - tooth decay contributor;
Microbe found in skin. (2)Staph - aureus, epidermidis; propionibacterium acnes - lives deep with follicles and pores;
Microbe found in urogenital tract. (3)Lactobactillus - acidophilus, iners, crispastus LOW pH thrive;
Candida albicans - vaginal yeast growth;
E. coli - from gut can cause UTI
Microbiome found in the intestine (4)1) Firmicutes - G(+) including clostridia;
2) Bacteriodetes - G(-) many obligate anerobes that ingest Carbs;
3) Proteobacteria - G(-) including E. coli. ;
4) Candida albicans - found in low levels leads to fungi infections in immunocompromised and antibiotic treated.

Section 2

Question Answer
What is the objective of the Human Microbiome Project?To better understand the microbial component of the human body, by promoting a comprehensive characterization of the complexity of human microbiome and an analysis of its role in health and disease.
What technique is the HMP emphasizing?Culture-independent identification technique: 16S rRNA gene sequence and metagenomics.
What is the role of Fecal microbiota transplant in key human disease?To restore microbiome components that were killed by a treatment by administering healthy individual feces saline solution.
What are some examples of how Fecal microbiota transplant is used?C. dificli; irritable bowel syndrome, inflammatory bowel (Chron's and ulcerative colitis)
How are perturbations of the microbiome correlated with disease?A less diverse microbiome appears to be predictive of disease. Microbiome altered by medical interventions (antibiotics, chemo, C-sections, diet) mark significant difference in composition of microbiomes.
What is the 16S rRNA gene?Component of 30S small subunit of bacterial ribosomes that can contains a highly conserved gene region between different species and a hypervariable region.
What is a biofilm?Complex community of bacteria that adheres to surfaces such as tooth, oral mucosal surface, or intestinal surface.
What is a probiotic?Live microorgansim that are believed to provide health benefits when consumed.
What are two culture-independent methods for characterizing the composition of the human microbiome?16S rRNA gene sequencing and metagenomics sequencing.
What technique is used in 16S rRNA gene sequencing?PCR primers added to highly conserved region and amplification of highly variable region results in amplicons used to identify bacterial at genus and species level.
Why is metagenomic sequencing used?16S rRNA sequencing is useful for identifying bacteria, but misses fungi and viruses.
What is metagenomic sequencing?Total DNA samples collected from human-associated microbial communities are sheared into pieces and sequenced. Database are used to identify bacteria, fungi, and viruses present in community.

Section 3

Question Answer
List 5 physiological responses to microbiome.metabolism, immunity, organ system development, vitamin production, colonization resistance.
Benefit of microbiome in metabolism.Resident bacteria help digest indigestible plant polyssacharides. Ex. bacteriodetes
Benefit of microbiome in immune system.Exposure helps shape development. Ex. intestinal microbiome essential for development of T-cell subpopulation (T-H17) and circulating T cells. Also, induces production of antimicrobial proteins from epithelium.
Benefit of microbiome in organ system development.Preliminary studies show role in neurodevelopment. Influences behavioral impairment.
Benefit of microbiome in vitamin production.Play key role in development of vit K and vit B.
Benefit of microbiome in colonization resistance.Occupies niches, compete with exogenous pathogens for nutrients, produce antibiotics and growth inhibitors reducing pathogen growth.