Dietary garcinol supplementation improves diarrhea and intestinal barrier function associated with its modulation of gut microbiota in weaned piglets

Background: The effects of dietary garcinol on diarrhea and intestinal barrier function associated with its modulation of gut microbiota in weaned piglets were investigated.Method: One hundred forty four weaned piglets(Duroc × Yorkshire × Landrace) from 16 pens(9 piglets per pen)were randomly divided into four treatment groups: controls(CON) or those supplemented with 200 mg/kg(LOW),400 mg/kg(MID), or 600 mg/kg(HIGH) diet garcinol. After 14-day trial, three piglets per pen were chosen to collect plasma, intestinal tissue and colonic digesta samples.Results: We demonstrated for the first time that garcinol promoted growth performance, as increased average daily feed intake(ADFI) and decreased feed/gain ratio(F/G); and reduced diarrhea incidence(P < 0.05); and strengthened antioxidant capacity, as an increased antioxidative index(P < 0.05). Additionally, garcinol ameliorated intestinal barrier dysfunction, as an increased villus height to crypt depth ratio, increased zonula occludens protein1(ZO-1), occludin and claudin-1 expression in the jejunum and ileum(P < 0.05), and decreased intestinal permeability(P < 0.05); and reduced inflammation, as decreased cytokine interleukin(IL)-6, IL-10, IL-1β and tumor necrosis factor-α(TNF-α) levels in the mucosa of the jejunum and ileum, and NF-κB p65 translocation(P < 0.05).Moreover, garcinol inhibited the growth of most harmful bacteria in the gut, especially Escherichia coli, and increased the growth of the beneficial bacteria Lactobacillus.Conclusion: This work provides a fundamental basis for the future development of garcinol-functional food use for improving diarrhea and intestinal barrier function in weaned piglets and for understanding the biological effects of garcinol and its potential as a functional feed additive.