Expression of cytokine and tight junction genes and ileal mucosal morphology in nursery pigs in response to garlic diallyl disulfide and diallyl trisulfide compounds

Bioactive components in garlic have anti-inflammatory, antioxidant, and immune modulatory properties that may improve gastrointestinal function in pigs. The current experiment was conducted to identify an effective dose of garlic-derived bioactive components diallyl disulfide (DADS) and diallyl trisulfide (DATS) and to evaluate the effect of graded doses of DADS and DATS on nursery pig performance and gastrointestinal function. Eight replicate pens of barrows were allotted on the basis of initial BW (12.45 kg ± 1.37) in a randomized complete block design to 1 of 6 treatments that consisted of administration of 0, 0.45, 0.90, 1.80, 3.60, or 7.20 mg DADS + DATS/kg BW. The DADS + DATS was administered daily by oral gavage to overnight-fasted pigs for a period of 6 d with soybean oil as the carrier and vehicle control. Growth performance and daily stool consistency scores were recorded. At the end of the experiment, pigs were euthanized and the mid ileum was excised for morphological and gene expression measurements. Mucosal gene expression was conducted by real-time PCR for mucin(MUC2), interleukin 8(IL-8), tumor necrosis factor(TNF-α), claudin 1(CL-1), occludin(OC), and zonula occludens 1(ZO-1). Supplementation with the oral gavage containing DADS + DATS did not affect growth performance or stool consistency, although there was a tendency (P= 0.06) for increased villus height. Expression of the IL-8gene was linearly increased (P= 0.01) and there was a tendency for a decrease (P= 0.07) in the ZO-1gene expression with oral DADS + DATS supplementation. There was no effect of the oral gavage on the expression of the MUC2, TNF-α, CL-1, and OCgenes. For the current experiment, the villus height plateaued at 381 μm, which was with daily oral supplementation of 1.71 mg DADS + DATS/kg BW. Furthermore, oral supplementation of DADS + DATS impacts IL-8and ZO-1gene expression, which may have implications on mucosal immune function and cellular integrity.