Segment-Specific Functional Responses of Swine Intestine to Time-Restricted Feeding Regime

Research indicates that TRF improves mammalian metabolism and health via the microbiota-gut-brain axis. Previous studies showed that TRF promotes pig growth, but the intestinal mechanisms remain unclear. This study explored the impact of TRF on pig intestinal functions. Twelve male pigs were split into ad libitum feeding (FA) and TRF groups. FA pigs had free access to feed, whereas TRF pigs were fed during 07:00-08:00, 12:00-13:00, and 17:00-18:00. TRF enhanced crude protein digestibility by 18.9% (p = 0.045) and increased pancreatic chymotrypsin and lipase activities, while reducing ileal amylase, sucrase, and lipase activities. Transcriptomic analysis identified 1339 differentially expressed genes (DEGs) in the jejunum and 268 in the colon, indicating segment-specific responses. Jejunal DEGs were associated with protein digestion and absorption (e.g., SLC1A1, SLC38A2, XPNPEP2), extracellular matrix-receptor interaction, and PI3K-Akt signaling, while colonic DEGs were linked to starch and sucrose metabolism and circadian entrainment. Importantly, TRF decreased colonic starch by 24% (p = 0.02) and cellulose by 18% (p = 0.04), with low impact on nitrogenous substrates. These results suggest that TRF improves protein absorption in the upper intestine and carbohydrate metabolism in the lower intestine, providing insights for refining TRF strategies in precision nutrition.