Digestive Health & Gut Nutrition Flashcards

Small Intestinal Bacterial Overgrowth (SIBO) is best defined as:

Answer: An abnormally high number of bacteria colonizing the small intestine

SIBO occurs when bacteria, often from the colon, proliferate abnormally in the small intestine (>10^3–10^5 CFU/mL), causing bloating, malabsorption, and diarrhea.

Which nutrient is most critical for maintaining intestinal mucosal integrity and supporting enterocyte proliferation?

Answer: Glutamine

Glutamine is the primary fuel source for enterocytes (intestinal lining cells) and is essential for maintaining tight junctions and the integrity of the intestinal mucosal barrier.

What is the key functional difference between soluble and insoluble dietary fiber?

Answer: Soluble fiber dissolves in water and forms a gel, slowing digestion; insoluble fiber does not dissolve and adds bulk to stool

Soluble fiber (oats, legumes) dissolves in water to form a viscous gel that slows digestion and helps lower cholesterol and blood glucose, while insoluble fiber (wheat bran, vegetables) resists dissolution and promotes bowel regularity by adding stool bulk.

Which dietary pattern is most consistently associated with greater gut microbiome diversity?

Answer: Plant-rich diet high in diverse fruits, vegetables, legumes, and whole grains

Research shows that diets rich in diverse plant foods increase microbiome diversity by providing a wide range of fiber substrates and phytonutrients that feed different microbial species.

Short-chain fatty acids (SCFAs) such as butyrate, propionate, and acetate are produced when gut bacteria ferment dietary fiber. What is a primary health benefit of butyrate specifically?

Answer: It serves as the main energy source for colonocytes and supports colon mucosal health

Butyrate is the preferred energy substrate for colonocytes (colon lining cells), supporting mucosal integrity, reducing inflammation, and playing a role in colorectal cancer prevention.

Lactose intolerance results from which physiological deficit?

Answer: Insufficient production of lactase enzyme to hydrolyze lactose into glucose and galactose

Lactose intolerance occurs when the small intestine produces insufficient lactase to break down lactose into absorbable monosaccharides, causing undigested lactose to reach the colon and produce gas, bloating, and diarrhea.

FODMAPs are a group of fermentable carbohydrates that can trigger symptoms in people with Irritable Bowel Syndrome (IBS). What does FODMAP stand for?

Answer: Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, And Polyols — short-chain carbohydrates that are poorly absorbed and rapidly fermented in the gut, producing gas and osmotic effects that trigger IBS symptoms.