Effects of antimicrobial peptide cathelicidin-BF on diarrhea controlling, immune responses, intestinal inflammation and intestinal barrier function in piglets with postweaning diarrhea.

The objective was to evaluate the effects of antimicrobial peptide cathelicidin-BF (C-BF) treatment on diarrhea controlling, immune responses, intestinal inflammation, and intestinal barrier function in piglets with postweaning diarrhea. In this study, fifty-four weaned piglets with diarrhea were selected and treated with saline (control), C-BF or norfloxacin nicotinic (NFN) for 7 days. Here, we investigated the effects of C-BF on diarrhea controlling, growth performance, serum immune indicators, intestinal morphology, intestinal inflammation, and intestinal epithelial barrier function in the weaned piglets with diarrhea. The results showed that C-BF treatment decreased (P < 0.05) diarrheal index and increased (P < 0.05) average daily gain (ADG) and average daily feed intake (ADFI) compared with control group. C-BF treatment decreased (P < 0.05) levels of serum blood urea nitrogen (BUN) and aspartate aminotransferase (AST), but increased (P < 0.05) levels of serum A/G and alkaline phosphatase (ALP) compared with control group. The concentrations of IL-6, IL-8, tumor necrosis factor-α (TNF-α), and IgG were lower (P < 0.05), but IgA was greater (P < 0.05) for piglets treated by C-BF compared with those in control group. C-BF and NFN treatment decreased (P < 0.05) IL-6, IL-8, IL-22, IL-10 and transforming growth factor-β (TGF-β) production in the jejunum and ileum compared with the control group. C-BF treatment increased the expression levels of zonula occluden-1 (ZO-1), Occludin, and Claudin-1 in the jejunum and colon compared with the control group and the NFN group. In conclusion, these data indicate that C-BF treatment may be an effective therapeutic strategy for controlling post-weaning diarrhea, improving immune responses, attenuating intestinal inflammation and enhancing intestinal barrier function in piglets with postweaning diarrhea.