Human Microbiome Flashcards
What are the common bacterial species found in the upper respiratory tract? 4
- Haemophilus influenzae
- Staphylococcus epidermidis
- Staphylococcus aureus
- Streptococcus pneumoniae
What are the main bacteria found on the skin? 3
- Staphylococcus epidermidis
- Staphylococcus aureus
- Lactobacillus species
Which bacteria are commonly found in the colon? 2
Lactobacillus species, Escherichia coli (E. coli)
What are commensal microbes?
Microbes that reside on body surfaces or mucosa without harming health
How does the microbiome composition vary?
It depends on body site and individual differences
What are key functions of the gut microbiome?4
- Stimulates immune system
- Prevents pathogen colonization
- Produces beneficial nutrients (e.g., Vitamin K)
- Metabolizes drugs and toxins
How can commensal bacteria cause infections?
By spreading to sterile body parts or increasing in numbers due to disturbances like antibiotics, immune deficiency, or pH imbalance
Which bacteria is a common cause of antibiotic-associated diarrhea?
Clostridium difficile
How does Clostridium difficile spread?
Person-to-person via the fecal-oral route
What treatment can restore gut microbiota balance in Clostridium difficile infections?
Fecal Microbiota Transplantation (FMT)
What are Koch’s postulates?
A set of criteria to establish a causal relationship between a microbe and disease
What is dysbiosis?
An imbalance in normal gut microbiota leading to harmful effects on the host
What are prebiotics?
Non-digestible food ingredients that stimulate beneficial bacterial growth in the gut
What are probiotics?
Live beneficial bacteria used as food ingredients to improve health
What is pharmacomicrobiomics?
The study of how the microbiome interacts with drugs and influences therapeutic responses
Why is microbiome research important in clinical practice?
It can aid in diagnostics, develop new therapies, and influence drug response predictions
What is the “One Health” concept in microbiome research?
It emphasizes that the microbiome is key to human health and varies by site and individual.
How does the microbiome develop over time?
It evolves from birth, influenced by diet, environment, and lifestyle.
How does Clostridium difficile cause disease?
- It forms spores that survive in the environment
- Overgrows in the gut after antibiotic use
- Produces toxins that damage intestinal lining, causing diarrhea
What is the role of bile salts in Clostridium difficile infection?
- Primary bile salts enhance C. difficile germination
- Secondary bile salts inhibit C. difficile growth
- Antibiotics reduce secondary bile salts, allowing C. difficile overgrowth
What is Fecal Microbiota Transplantation (FMT)?
A treatment that transfers healthy gut bacteria from a donor to restore microbiome balance in patients with recurrent C. difficile infections.
What is the limitation of Koch’s postulates in modern microbiology?
They do not account for polymicrobial diseases or microbiome-related conditions where no single pathogen is responsible.
How does dysbiosis contribute to chronic diseases?
It alters immune responses, increases inflammation, and disrupts metabolic processes.
Name some diseases linked to chronic inflammation and dysbiosis.
Atherosclerosis
Arthritis
Neurodegenerative diseases (e.g., Alzheimer’s, dementia)
Depression
What are probiotics used for?
They help restore or maintain a healthy microbiome by introducing beneficial live bacteria.
Give an example of a probiotic strain and its benefit.
Lactobacillus species—helps maintain gut and vaginal health.
What are the main challenges in microbiome research?
- Reproducibility of studies
- Variability between individuals
- Translating animal model findings to humans
- Distinguishing bacterial vs. viral contributions to disease
What is pharmacomicrobiomics?
The study of how the microbiome influences drug metabolism and therapeutic responses.
