Which of the following is a direct metabolic benefit of short chain fatty acids to colonocytes?

• A. Promote mucus degradation
• B. Increase gastric acid secretion
• C. Provide a source of calories
• D. Inhibit epithelial repair

Answer: (C)

Short-chain fatty acids produced by microbial fermentation of fiber are used directly by colonocytes as an energy source. Butyrate, in particular, serves as the preferred fuel for these cells, providing calories that power basic cellular functions, maintenance, and repair of the colon lining. That direct metabolic benefit—fuel for energy production in the colonocytes—explains why providing calories is the correct choice. The other options don’t fit because SCFAs aren’t about promoting mucus degradation, they don’t trigger gastric acid secretion in the stomach, and they actually support, rather than inhibit, epithelial health and repair.