Podcast
Questions and Answers
What is the estimated number of microbial species on Earth?
What is the estimated number of microbial species on Earth?
The human body has more human cells than microbes.
The human body has more human cells than microbes.
False
What is microbiota?
What is microbiota?
The total microbial population of a given site or habitat.
What influences the human microbiota?
What influences the human microbiota?
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What is the gut-brain axis (GBA) involved in?
What is the gut-brain axis (GBA) involved in?
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The beneficial relationship between two independent organisms is called ______.
The beneficial relationship between two independent organisms is called ______.
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What is commensalism?
What is commensalism?
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Dysbiosis can lead to disease.
Dysbiosis can lead to disease.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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What role does the skin microbiota play?
What role does the skin microbiota play?
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What type of organisms are primarily found in the mouth microbiota?
What type of organisms are primarily found in the mouth microbiota?
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Study Notes
Microbial Diversity
- Estimated microbial species on Earth could be as high as 10^12.
- Human body comprises roughly 10^13 human cells to 10^14 microbial cells.
Microbiota vs. Microbiome
- Microbiota refers to the total microbial population in a specific habitat (e.g., gastrointestinal microbiota).
- Microbiome encompasses the genetic content of the microbiota.
Influencing Factors
- Microbial composition affected by pH levels, water availability, nutritional content, and oxygen levels.
Human Microbiota and Health
- Microbiota communicate bidirectionally with the gut-brain axis, impacting metabolism, gastrointestinal homeostasis, appetite regulation, stress, anxiety, and memory.
- Gut-brain axis helps stimulate immune response, aiding normal immune system development.
- Microbiota increase metabolic capabilities and serve as a physical barrier against pathogens by competing for resources and producing antimicrobial substances.
Symbiotic Relationships
- Mutualism: Two organisms benefit from each other (e.g., gut bacteria metabolizing undigested carbohydrates, enhancing nutrient availability).
- Commensalism: One organism benefits while the other is unaffected (e.g., oral microbiota utilizing sugars without impacting human health).
- Relationship can shift to disease state with environmental changes (e.g., dietary changes).
- Parasitism: One organism benefits at the host's expense, often transforming symbiotic microbiota into harmful parasites under conditions of dysbiosis.
Microbiota Locations
- Skin: Acts as a mechanical barrier to infection, inhospitable to many microbes due to low moisture, high salt concentration, and acidity.
- Mouth: Home to complex microbial communities, including 500-600 bacteria types, primarily anaerobes.
- Oral cavity serves as an entry point for pathogens targeting the upper respiratory tract.
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Description
Explore the intricate interactions between host and pathogens in this first week of our microbiology course. Learn about the vast diversity of microbial species and the roles of microbiota and microbiome in human health. Understand how environmental factors influence microbial populations.
