Notes 20100422 Bacteria in your belly - Guest lecture
From SnOwy - Ed's Wiki Notebook
Contents |
Notes
- Eric Dunford from Dr. Josh's lab
- microbial links to human diseases
- microbiome in the human gut
- roughly 0.1 of cells in our body is human
- humans are colonized shortly after being born
- biofilms (plaque on teeth)
- bacterial species have evolved to colonize each environment
- after one year of age, the bacterial content in your body is set
- balance of microbe species and abundance are resilient to stressors (illness etc.)
Stomachs
- 3 phyla
- firmicutes
- archaea
- bacteroidetes, actinobacteria
The famous stomach ulcer case
- helicobacter pylori accidentally discovered by Drs. Marshall and Warren by overgrown culture
- helix-shaped gram negative
- burrows into mucosa of stomach; urease used to produce carbon dioxide etc-- local basic area
- 0.5 of world population infected, most are asymptomatic
Depression, obesity
- Ley et al, 2005: rodent gut and human gut microflora strongly corelated
- leptin assists in feeling full after eating
- leptin resistance produces obesity
- resistance to leptin changes gut microflora population
- lean individuals have greater gut phylogenetic diversity
- Firmicutes predominant in overweight and obese
- Trend: When individuals have had gastric bypass, the enteric biota diversifies as a response
Irritable bowel syndrome
- Is there a bacterium that is implicated?
- C. jejuni, Salmonella, Shigella, E. coli
- SIBO: Small intestinal bacteria overgrowth
Depression
- do microbes emit neural transmitters?
- Forsythe et al, 2010: gut microbiome; mood; behaviour
- evidence microbiota affects CNS, PNS
- Stress: stress changes composition of gut microflora
- Anxiety
- Neural Transmitters: --
- mood altering neural transmitters-- emitted through guy epithelium, blood stream, hypothalamus -- what about first pass effect?
- some of the gut microbes are correlated with liver and kidney disease
- obese persons 0.55 become depressed; depressed persons 0.58 become obese ...
Fun Facts
- Japanese gut microbiota able to digest seaweed
- able to match bacterial communities with skin -- keyboard, forensics -- degeneracy, resolution?
- Answer: this wasn't a very high-resolution technique, it is in the 70% to 90% range for certainty
Questions
- eukaryotic species, yeast, viruses?
- is more sterile actually bad?
- c-section, inoculation with birth canal?
