Probiotics-induced feed fermentation can improve the composition of microbiota, leading to benefits in pig production. However, the influence of probiotics-driven feed fermentation on pollution reduction is limited. This study aimed to analyze the impact of Weissella-based feed fermentation on the chemical characteristics, changes in microbial abundance, and antibiotic resistance genes (ARGs). Moreover, the possible mechanism and the association among them was also analyzed. First, pigs reared on fermented feed exhibited improved growth performance. The fermentation group showed a significant reduction in emissions of total phosphorus (TP), total carbon (TC), organic matter (OM), copper (Cu), and zinc (Zn) levels in feces compared to the control group. The fermentation group also showed a significant decrease in the ARGs, especially for the tetX, tetW, tetQ, tetL, tetO, tet32, tet44, ermG, ermF, CfxA2, CfxA3, aph3-III, aadA, and ant9-I, compared to the control group. The primary functional microbiota, characterized by increased levels of Bifidobacterium, Megasphaera, and Mitsuokella, and decreased levels of Methanosphaera, and Ruminiclostridium, displayed both negative and positive correlations with ARGs, TC, TP, OM, Cu, and Zn. Furthermore, a significant association was observed between the alterations in microbiota and ARGs and the lactic acid concentration in the fermented feed. The molecular docking results showed a good fit between lactate dehydrogenase and three antibiotics, particularly tetracycline. In conclusion, these results offer novel targets and strategies to address environmental pollutants associated with pig farming.

In this study, the effects of pediocin (PP) on intestinal barrier function, renal injury, and immune regulation were evaluated in Salmonella pullorum-infected chickens. Forty-five 7-day-old specific-pathogen-free (SPF) chickens were randomly assigned to three groups: control (CON), S. pullorum infection (SP), and S. pullorum infection + PP treatment (SPA). The results showed that S. pullorum infection significantly elevated (p < 0.05) the renal (CREA, UREA), hepatic (ALT, AST), immunological (IgG, IgM), and inflammatory (TNF-α, IL-6, SAA, CRP) parameters, as well as the expression of trefoil factor 3, Toll-like receptor 2, TNF-α, IL-1β, and IL-6. In contrast, the jejunal villus height and the villus-to-crypt ratio, and the expression of intestinal tight junction proteins (occludin, claudin-1, and Zonula occludens-1), mucin-2, and transforming growth factor-β1 were significantly decreased in both the SP and SPA groups. In the SP group, the parameter alterations observed at 6 DPI compared to the CON group persisted until 12 DPI. In contrast, in the SPA group, these parameters returned to levels comparable to those of the CON group after 6 days of PP treatment. Moreover, S. pullorum infection markedly reduced the α-diversity of the gut microbiota, and this reduction could be partially restored following PP treatment. At the phylum level, S. pullorum infection significantly reduced the relative abundances of Proteobacteria and Verrucomicrobia. PP treatment increased the abundances of Firmicutes and Actinobacteria, while also restoring the abundances of Proteobacteria and Verrucomicrobia to some extent. At the genus level, PP treatment significantly increased the abundance of Faecalibacterium and Lactobacillus. Additionally, Faecalibacterium and Butyricicoccus were significantly more abundant in the SPA group. Thus, PP could alleviate S. pullorum infection induced intestinal barrier damage, reduce immune stress responses, and exert a protective effect by modulating the composition of the intestinal microbiota of chickens.