Bacterial lipopolysaccharide with different administration routes affects intestinal mucosal morphological, immunological, and microbial barrier functions in goslings

The current study was conducted to evaluate the effects of different administration routes of bacterial lipopolysaccharide (LPS) on intestinal muco -sal morphological, immunological, and microbial barrier functions in goslings. First, we compared intestinal villi morphology of goslings under intraperitoneal or oral LPS treatment through hematoxylin and eosin staining. Then, we determined the signatures of the microbiome in the ileum mucosa of goslings subjected to oral LPS treatment at 0, 2, 4, and 8 mg/kg BW by 16S sequenc-ing, and analyzed the changes in intestinal barrier func-tions and permeability, levels of LPS in the ileum mucosa, plasma, and liver tissue, and the induced inflammatory response of Toll-like receptor 4 (TLR4). As a result, intraperitoneal LPS injection resulted in a thicker intestinal wall in the ileum within a short time, whereas villus height was less affected; in contrast, oral LPS treatment exerted a stronger influence on villus height but not on intestinal wall thickness. We also found that oral LPS treatment affected the structure of the intestinal microbiome, reflected by changes in the clustering of intestinal microbiota. The average abun-dance of Muribaculaceae showed an increasing trend with increasing LPS levels, and that of the genus Bacter-oides decreased, compared with the control group. In addition, oral LPS treatment with 8 mg/kg BW affected the intestinal epithelial morphology, damage the muco -sal immune barrier, downregulated the expression of tight junction proteins, increased circulating D-lactate levels, and stimulated the secretion of various inflamma-tory mediators and activation of the TLR4/MyD88/ NFKB pathway. This study presented the injuries of intestinal mucosal barrier function induced by LPS chal-lenges in goslings and provided a scientific model for searching the novel strategies to attenuate the immuno-logical stress and gut injury caused by LPS.

Automated summary

This study evaluated the effects of different administration routes of bacterial lipopolysaccharide (LPS) on intestinal mucosal morphology, immunological function, and microbial barrier in goslings. The results showed that intraperitoneal LPS injection increased the thickness of the intestinal wall, while oral LPS treatment primarily affected the villus height. Moreover, oral LPS treatment altered the structure of the intestinal microbiome and caused damage to the mucosal immune barrier.