Natural Betaine Maintains Intestinal Epithelial Cell Integrity and Energy Levels and Does Not Induce Immune Reactions in an in vitro Caco-2 Model Compared with Synthetic Betaine-HCL

摘要

Betaine is commonly used in feed, improving feed conversion ratios and performance in animals.Betaine can be supplemented as natural betaine, isolated from natural sources; synthetic anhydrous betaineor synthetic betaine-HCl. Scientific data on the comparison between synthetic betaine-HCl and natural betaineare limited, prompting us to examine whether the 2 forms of betaine have disparate cellular effects. Naturalbetaine or betaine-HCl was mixed with feed in equimolar amounts and subjected to in vitro digestion, mimickingthe conditions in the upper gastrointestinal tract of poultry. After digestion, the soluble component wasseparated and Caco-2 intestinal epithelial cells were used to examine how soluble factors affect inflammatorymarkers, ATP and tight junction integrity at 1, 6 and 24 h after treatment. Soluble factors from in vitro-digestedfeed that was supplemented with betaine-HCl changed significantly compared with those from control feed orfeed to which natural betaine was added. Tight junction integrity at 1 and 6 h decreased, recovering to basallevels at 24 h. ATP levels declined after 1 h and were restored to baseline values after 6 and 24 h. IL-8 rose after6 and 24 h as did IL-6 after 24 h, indicating that betaine-HCl induces inflammatory responses in Caco-2 cellscompared with natural betaine and the control. Our results show that despite possessing the same core betainemolecule, synthetic betaine-HCl induced cellular changes that were indicative of transient damage in cells.Thus, the supplementation of feed with various sources of betaine is not equal at the cellular level which caninfluence animal performance and welfare, especially during stress.