NTA Digestion & Gut Health 2 — Questions and Answers
Question 1: What term describes an imbalance in the composition or function of the gut microbiome?
- Eubiosis
- Dysbiosis (Correct answer)
- Microbiosis
- Symbiosis
Correct answer: Dysbiosis
Dysbiosis refers to a disruption in the normal microbial community of the gut, characterized by reduced diversity or overgrowth of potentially harmful organisms.
Question 2: Short-chain fatty acids (SCFAs) such as butyrate are produced when gut bacteria ferment which dietary component?
- Dietary protein
- Saturated fat
- Prebiotic fiber (Correct answer)
- Simple sugars
Correct answer: Prebiotic fiber
Beneficial colonic bacteria ferment non-digestible prebiotic fibers (e.g., inulin, pectin, resistant starch) to produce butyrate and other SCFAs that fuel colonocytes and support gut barrier integrity.
Question 3: Which type of intestinal cell produces mucus that forms the protective layer between gut contents and the epithelium?
- Enterocytes
- Goblet cells (Correct answer)
- Paneth cells
- Enteroendocrine cells
Correct answer: Goblet cells
Goblet cells are specialized intestinal epithelial cells that secrete mucins, which form the mucus gel layer acting as a physical barrier against pathogens and antigens.
Question 4: In the context of 'leaky gut' (intestinal hyperpermeability), which protein structures are primarily disrupted?
- Desmosomes
- Tight junctions (Correct answer)
- Gap junctions
- Adherens junctions
Correct answer: Tight junctions
Tight junctions (composed of claudins, occludins, and ZO proteins) seal the spaces between enterocytes; their disruption allows larger molecules and antigens to pass paracellularly into systemic circulation.
Question 5: Which of the following best describes small intestinal bacterial overgrowth (SIBO)?
- Deficiency of Lactobacillus in the large intestine
- Excessive colonization of bacteria in the small intestine beyond normal levels (Correct answer)
- Overgrowth of Candida in the colon
- Insufficient stomach acid causing colonic fermentation
Correct answer: Excessive colonization of bacteria in the small intestine beyond normal levels
SIBO is defined as an abnormal increase in bacteria (>10^3 CFU/mL) in the small intestine, typically microbes that normally reside in the colon, causing bloating, malabsorption, and altered motility.
Question 6: Secretory IgA (sIgA) in the gut plays which immunological role?
- Directly lysing bacterial cell walls
- Binding pathogens and antigens in the gut lumen to prevent epithelial adhesion (Correct answer)
- Activating mast cells to release histamine
- Producing hydrochloric acid to denature foreign proteins
Correct answer: Binding pathogens and antigens in the gut lumen to prevent epithelial adhesion
sIgA is the predominant antibody in intestinal secretions; it binds pathogens, toxins, and food antigens, neutralizing them and preventing attachment to mucosal cells without causing inflammation.
Question 7: Which dietary pattern is most associated with reducing gut microbiome diversity, according to current research?
- Traditional whole-food, plant-rich diet
- High intake of fermented foods
- Western diet high in ultra-processed foods and low in fiber (Correct answer)
- Mediterranean diet with moderate red wine
Correct answer: Western diet high in ultra-processed foods and low in fiber
Ultra-processed, low-fiber Western diets reduce the variety of substrates available to gut bacteria, leading to decreased microbial species diversity — a marker associated with poor metabolic and immune health.
NTA Digestion & Gut Health 2
What term describes an imbalance in the composition or function of the gut microbiome?