Lactobacillus combination alleviates dextran sulfate sodium-induced colitis in Wuzhishan minipigs

Inflammatory bowel disease (IBD) poses a grave threat to human health, and minipigs are physiologically more analogous to humans than rodents. Probiotics are widely recognized for their ability to regulate the immune microenvironment and improve barrier function; however, the role of Lactobacillus combination in IBD has not been fully studied. The present study was conducted to investigate the anti-inflammatory effects of Lactobacillus combination (Lactobacillus crispatus, Lactobacillus johnsonii and Lactobacillus reuteri) on dextran sodium sulfate (DSS)-treated Wuzhishan minipigs. A total of thirteen healthy Wuzhishan minipigs were randomly divided into three groups: a CON group, a DSS group, and a DSS + LAB group. On days 8 and 23 of the experiment, the Lactobacillus mixture or DSS solution was administered to the piglets. The results demonstrated that the Lactobacillus mixture exhibited a positive effect on weight reduction and colon histopathology scores. The administration of DSS resulted in a substantial augmentation in the expression of proinflammatory cytokines, including interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α). The Lactobacillus mixture supplement was found to suppress the upregulation of proinflammatory cytokines (IL-1β) and the downregulation of anti-inflammatory cytokines (transforming growth factor beta 1 (TGF-β1)), while increasing the expression levels of tight junction protein zonula occludens-1 (ZO-1) and mucin 1 (MUC1). Furthermore, improvements in the content of oxidative stress indicators and short-chain fatty acids (SCFAs) were observed under the mediation of the Lactobacillus mixture. 16S rRNA sequencing revealed that the Lactobacillus mixture was effective in reducing the relative abundance of harmful bacteria and increasing that of beneficial bacteria, thereby reshaping the intestinal microbiota structure of Wuzhishan minipigs with DSS-induced colitis and further altering the metabolic pathways of the intestinal microbiota. This study provides a novel reference and scientific basis for the application of Lactobacillus in the treatment of colitis and for the food industry to develop functional probiotic products.