Microbial Flora and Human Health MCQs

1. : Which of the following best describes the role of the human gut microbiota?
(A) It helps in the digestion of proteins only
(B) It assists in the synthesis of vitamins and breakdown of complex carbohydrates
(C) It exclusively protects against viral infections
(D) It solely helps in the absorption of minerals

2. : Which microorganism is commonly found in the human skin microbiota and can sometimes cause infections when the skin is compromised?
(A) Escherichia coli
(B) Staphylococcus epidermidis
(C) Lactobacillus acidophilus
(D) Bacteroides fragilis

3. : Which of the following is a key function of probiotics in the human gut?
(A) Increasing the growth of pathogenic bacteria
(B) Enhancing the immune response and maintaining gut barrier function
(C) Destroying all bacteria in the gut
(D) Reducing the absorption of nutrients

4. : Which area of the human body is typically sterile in a healthy individual under normal conditions?
(A) Skin
(B) Mouth
(C) Urinary bladder
(D) Gut

5. : Which microorganism is a common inhabitant of the female genital microbiota and helps maintain a low pH to prevent infections?
(A) Candida albicans
(B) Lactobacillus spp.
(C) Staphylococcus aureus
(D) Escherichia coli

6. : What can lead to dysbiosis, an imbalance in the microbial flora of the gut?
(A) Balanced diet
(B) Prolonged use of antibiotics
(C) Regular exercise
(D) Adequate hydration

7. : Which of the following is a possible consequence of disrupting the normal microbial flora through antibiotic use?
(A) Decreased risk of obesity
(B) Enhanced resistance to infections
(C) Increased risk of Clostridium difficile infection
(D) Improved digestion

8. : Which microorganism is commonly found in the oral cavity and can contribute to dental caries?
(A) Streptococcus mutans
(B) Bacteroides fragilis
(C) Lactobacillus rhamnosus
(D) Propionibacterium acnes

9. : How does the human microbiota influence the development of the immune system?
(A) By promoting the overgrowth of pathogenic bacteria
(B) By directly suppressing the production of antibodies
(C) By interacting with the immune system to shape its response to pathogens
(D) By causing chronic inflammation

10. : Which of the following factors can significantly alter the composition of the gut microbiota?
(A) Dietary changes
(B) Normal hydration
(C) Regular sleep
(D) Routine physical activity

11. : Which microorganism is often used as a probiotic to promote gut health?
(A) Lactobacillus acidophilus
(B) Escherichia coli
(C) Staphylococcus epidermidis
(D) Pseudomonas aeruginosa

12. : Which of the following is a major role of the skin microbiota?
(A) Synthesis of digestive enzymes
(B) Preventing colonization by pathogenic microbes
(C) Producing antibodies
(D) Digesting carbohydrates

13. : What is the primary method by which the gut microbiota helps in the metabolism of dietary fiber?
(A) By synthesizing vitamins
(B) By breaking down fiber into short-chain fatty acids
(C) By converting fiber into proteins
(D) By synthesizing hormones

14. : Which type of relationship do humans and their resident gut microbiota generally have?
(A) Parasitic
(B) Symbiotic
(C) Commensal
(D) Pathogenic

15. : What is the effect of a high-fiber diet on the gut microbiota?
(A) It decreases microbial diversity
(B) It increases the growth of beneficial bacteria
(C) It promotes the growth of pathogenic bacteria
(D) It reduces the production of short-chain fatty acids