Dietary supplementation with <i>Clostridium butyricum</i> helps to improve the intestinal barrier function of weaned piglets challenged with enterotoxigenic <i>Escherichia coli</i> K88

Abstract

AIMS: The objective of this study was twofold: (i) to examine the effect of Clostridium butyricum on intestinal barrier function and (ii) to elucidate the mechanisms involved in enhanced intestinal barrier function. METHODS AND RESULTS: Forty-eight weaned piglets were assigned randomly to either a basal diet or a C. butyricum-supplemented diet. On day 15, all pigs were orally challenged with enterotoxigenic Escherichia coli (ETEC) K88 or saline. Clostridium butyricum decreased serum diamine oxidase activity and d-lactic acid concentration, as well as increased intestinal tight junction proteins (ZO-1, claudin-3 and occludin) expression in ETEC K88-infected pigs. Moreover, C. butyricum decreased IL-1β and IL-18 levels in serum and gut, whereas it increased IL-10 levels. Furthermore, C. butyricum downregulated NLRP3 and caspase-1 expression in ETEC K88-challenged pig gut, but did not affect apoptosis-associated speck-like protein expression. CONCLUSIONS: Clostridium butyricum enhanced intestinal barrier function and inhibited apoptosis-associated speck-like protein-independent NLRP3 inflammasome signalling pathway in weaned piglets after ETEC K88 challenge. SIGNIFICANCE AND IMPACT OF THE STUDY: The novelty of this study lies in the beneficial effects of C. butyricum on intestinal health, likely by improving intestinal barrier function and alleviating inflammatory reactions.