Clinical Nutritionist CCN Gastrointestinal Health and Nutrition 1

Question 1

Which probiotic strain has the most robust clinical evidence for preventing antibiotic-associated diarrhea?

Accepted Answer

Lactobacillus rhamnosus GG

Answer

Lactobacillus rhamnosus GG has the strongest and most consistent evidence across clinical trials for reducing antibiotic-associated diarrhea.

Question 2

The primary site of vitamin B12 absorption in the gastrointestinal tract is the:

Accepted Answer

Terminal ileum

Answer

Vitamin B12 bound to intrinsic factor is absorbed exclusively in the terminal ileum via specific cubilin receptors.

Question 3

Which dietary fiber type has the strongest evidence for lowering LDL cholesterol?

Accepted Answer

Soluble fiber (beta-glucan)

Answer

Soluble fiber, particularly beta-glucan from oats, forms a viscous gel that binds bile acids and reduces LDL cholesterol through enterohepatic recycling.

Question 4

Increased intestinal permeability ('leaky gut') is primarily caused by dysregulation of:

Accepted Answer

Tight junction proteins

Answer

Leaky gut results from disruption of tight junction proteins (such as occludin and claudins) that normally seal the paracellular space between enterocytes.

Question 5

Short-chain fatty acids (SCFAs) produced by colonic fermentation of fiber primarily serve as the main energy source for:

Accepted Answer

Colonocytes

Answer

SCFAs—especially butyrate—are the preferred fuel for colonocytes, providing approximately 70% of their energy needs.

Clinical Nutritionist CCN Practice Test

Clinical Nutritionist CCN Practice Test

Clinical Nutritionist CCN Gastrointestinal Health and Nutrition 1