Microbiome (Jenney) Flashcards
What are 2 things that microbiota can affect in us?
Behavior and brain development
All microorganisms inhabiting our body, including viruses, porkaryotes (bacteria & archaea), protozoa, and fungi are known as what?
Microbiota
About how many cells make up the human microbiota
10^18
The gut microbiota can be considered what?
A pseudo-organ, with a mass approximately the same as the liver
Full complement of all proteins is?
Proteome
Full complement of sugars/glycoproteins is?
Glyco(proteo)me
Full complement of kinases is?
Kinome
All metals found in an organism make up the?
Metallome
All the metalloproteins are found where?
Metalloproteome
All possible mRNA transcripts are found where?
Transcriptome
Complete coding region of a genome (exons filtered out of a whole genome DNA sequence) is known as the?
Exome
Genes from all possible microbes living in a particular niche (e.g. intestinal microbiota) make up the?
Microbiome
New field created to analyze data involving proteomes, exomes, microbiomes, etc. is called?
Bioinformatics
Complete genetic material (DNA) of an organism is called?
Genome
It is estimated that there are about how many unique genes in the human microbiome, as opposed to the human genome?
100 times more (genome has 20,000)
Where are human gut microbiota located?
Clusters differ in different regions of the GI tract.
Microbiota specific to a tissue/region are known as?
Local microbiota
Microbiota representing the community common to a population are known as?
Core microbiota
Pool of genes found commonly in a community is known as?
Core metagenome
Mobile genetic elements in the microbiota which can transfer antibiotic resistance genes make up the?
Mobile metagenome
All metabolism performed by the microbiota is known as?
Metabolome
All gene transcripts of the metagenome are examined using what?
Metatranscriptomics
All expressed proteins in the metagenome are examined using what?
Metaproteonomics
What microbacteria make up about 80% of the gut?
Clostridia, eubacteria, bacteroides
What lab techniques are used to study the diversity of the microbiota?
FISH T-RFLP Real-Time PCR Phylogenetic microarray Pyrosequencing
The metagenome of _____ _____ is a key aspect of human health.
GI tract
What are some problems encountered with studying the GI tract?
Contamination Artifacts Sampling Spatial/temporal variability Standardization
Metagenomics is leading to a new field, which is designed to identify the genetic determinants involved in the health promoting effects of probiotic bacteria. What is this field called?
Probiogenomics
Why should we care about probiogenomics?
There are clear shifts in microbiota in diseased states. Research has shown that there are clear differences in human microbiota in healthy vs. ill individuals
Clusters of bacterial species that are shared among different groups of people are known as what?
Enterotypes
What serves as an important potential source of diagnostic biomarkers, 12 bacterial genes that significantly correlate with human age and 3 functional modules (groups of genes) that correlate with BMI?
Enterotypes
What is an abnormal microbial ecosystem in the host known as?
Dysbiosis
What does dysbiosis correlate with?
Cause and progression of disease states e.g. obesity, diabetes, IBS, some GI tract cancers
When treating a patient and his/her microbiota, what are you actually treating?
Microecological disease
What are permanent residents of the microbiota that have the potential to induce pathology?
Pathobionts
What do colostrum and breast milk contain that are believed to define some of the early responses infants have to commensals? What do they do?
Live microbes, metabolites, IgA, immune cells, cytokines - these factors synergize to shape the breast-fed infant microbiota and the response of the host to these microbes.
The presence of what in the mother’s milk promotes expansion of defined constituents of the microbiota, such as Bifidobacterium?
Metabolites, including oligosaccharides
The developing immune system is characterized by what type of cell production and development in favor of regulatory responses?
Blunted inflammatory cytokine production
Skewed T & B cell development
What is a consequence of the developing state of the immune system?
High susceptibility to infections
Recent reports reveal that what contributes to maintenance of immunoregulatory environment and limits mucosal inflammation following colonization with microbiota in the neonate?
Defined population of erythroid cells
What do neonate innate cells express that unlike in adults has a notable impairment in production of inflammatory mediators, e.g. oxygen radicals and heightened production of regulatory cytokines like IL-10?
TLR ligands
Other than the immune system, what are gut bacteria also an important factor for the development of?
Gut structure
Microbiota play a critical role in what kind of structure development, specifically?
Lymphoid
The capacity of the microbiota to stimulate innate responses translates into its important role in the induction of what kind of immunity?
Adaptive
Early studies have indicated what kind of host immune responses to pathogens in mice treated with antibiotics or raised in germ-free conditions?
Significantly impaired
What toxins do GAS bacteria release that can generate ER stress that upregulates the expression of asparagine synthetase and increases production of asparagine?
Streptolysin O (SLO) Streptolysin S (SLS)
What happens as a result of upregulated ASN production due to a GAS infection?
Gene expression of the bacteria and an increased rate of its growth
What kind of immune responses have been shown to be influenced by the intestinal microbiota?
Mucosal and systemic
Research was done in which a diet enriched in 5% acidic oligosaccharides derived from pectin (pAOS) was given to mice with chronic P. aeruginosa infections. What happened to lung bacterial clearance in the mice after the first and second P aeruginosa infections?
It increased
Microbiota interactions in infancy may be critical determinants of what?
Long-term host metabolic effects
What does LDP exposure enhance?
HFD metabolic effects, which can be transmissible by transferring the microbiota
What has research recently begun to show in terms of bacteria and cancer?
That bacteria can drive tumor growth, and their interaction with the immune system can further fuel cancer progression, especially at mucosal interfaces where bacteria are abundant and the immune system is highly reactive
What gut bacterial metabolite can directly cause DNA damage and, in turn, promote tumor development?
Deoxycholic acid (DCA)
What bacterium has been shown to directly promote intestinal tumorigenesis when its adhesin, FadA, binds to E-cadherin on epithelial cells and activates beta-catenin signaling to promote epithelial cell proliferation?
Fusobacterium nucleatum
What is an indirect mechanism by which bacteria promote tumor growth?
Chronic activation of the immune system
What can microbiota increase that can induce triglyceride production in the liver? This is also associated with greater adiposity and reduced glucose tolerance.
Serum levels of glucose and SCFAS
What does gut microbiota regulate that regulates fatty acid oxidation in both muscle and adipose tissue?
Angiopoietin-like protein 4 (Angptl4/Fiaf - fasting-induced adipose factor)
What can gut bacteria do regarding inflammation and insulin resistance associated with obesity, possibly via LPS?
Initiate it
What kind of effect has been shown in germ-free mice regarding obesity?
Bacteria may play a role in weight gain; germ free mice who were given gut bacteria from normal mice dramatically put on weight within 10-14 days
What kind of transplant is now being performed for patients infected with a virulent, basically non-treatable strain of C. diff?
Fecal - from individuals with healthy gut bacteria
What systems are affected by microbiota?
Intestinal Exocrine Vascular Endocrine Infection Immunity Epithelia Morphology Metabolism Nutrional Hepatic