Putaala H, Lehtinen M, Tiihonen K and Nurminen P

Journal of Animal and Veterinary Advances. 2018;17:74-81

DOI: 10.36478/javaa.2018.74.81

Abstract: 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 betaine or synthetic betaine-HCl. Scientific data on the comparison between synthetic betaine-HCl and natural betaine are limited, prompting us to examine whether the 2 forms of betaine have disparate cellular effects. Natural betaine or betaine-HCl was mixed with feed in equimolar amounts and subjected to in vitro digestion, mimicking the conditions in the upper gastrointestinal tract of poultry. After digestion, the soluble component was separated and Caco-2 intestinal epithelial cells were used to examine how soluble factors affect inflammatory markers, ATP and tight junction integrity at 1, 6 and 24 h after treatment. Soluble factors from in vitro-digested feed that was supplemented with betaine-HCl changed significantly compared with those from control feed or feed to which natural betaine was added. Tight junction integrity at 1 and 6 h decreased, recovering to basal levels at 24 h. ATP levels declined after 1 h and were restored to baseline values after 6 and 24 h. IL-8 rose after 6 and 24 h as did IL-6 after 24 h, indicating that betaine-HCl induces inflammatory responses in Caco-2 cells compared with natural betaine and the control. Our results show that despite possessing the same core betaine molecule, 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 can influence animal performance and welfare, especially during stress.