BIOL 2303 Lecture Notes - Lecture 17: Carcinogen, Enema, Inflammatory Bowel Disease
18 Apr 2018
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Document Summary
Normal flora: microorganisms normally present on/in a healthy host (microbiome) Opportunistic pathogen: microorganism that only causes disease under special conditions. The human microbiome: the collection of microorganism living on or in the human body. Often mutually beneficial: microbes produce beneficial products, outcompete pathogens, host provides environments for growth. Tremendous variation: different parts of the body, different individuals. Humans are predominantly microbial: 10x as many microbial cells than human cells. Microflora limited to surfaces exposed to environment. Deeper into the body tissue, the fewer organisms present ex: mouth, throat high populations, but few in the lungs high population in urethra but bladder fewer, kidneys should have none. Microbes living in the intestines are of interest: diversity, function- ex: vitamin synthesis, consequences of disruption- colonization by pathogens. Density of microbes increases as food passes through the gastrointestinal tract (gi tract) Different types of bacteria live in different sections. This is based on ph, oxygen concentrations and nutrient availability.
