The gut microbiota is engaged in multiple interactions affecting host health, and gut dysbiosis can lead to many diseases. However, the effects of acetylcysteine (NAC) on the gut microbiome composition in pigs using metagenomic sequencing have not been reported. In this study, we used metagenome sequencing to study the effects of NAC on the pig gut microbiome. Sequencing results showed that microbial diversity was changed after NAC treatment. Antibiotic Resistance Genes Database (ARDB) analysis demonstrated that the main genes modified were macb, tsnr, norm, bl2be-per, vansb and pbp1b in the NAC group. Our data showed that NAC could affect microbial distribution at the phylum, gene and species levels. At the species level, NAC significantly increased the abundances of Megasphaera, Lactobacillus reuteri and Megasphaeraelsdenii and reduced the abundances of Phascolarctobacterium succinatutens, Prevotellacopri and Selenomonasbovis compared with the control group. In addition, Gene Ontology (GO) analysis revealed that in the NAC group, cellular process, metabolic process and single-organism process were the dominant terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that RNA transport, MAPK signaling pathway, cell cycle, glycosylphosphatidylinositol (GPI)-anchor biosynthesis and VEGF signaling pathway were the dominant signaling pathways in the NAC group. In conclusion, our results suggest that NAC may modify the piglet gut microbiome composition and these findings might provide a new strategy for maintaining animal and human health in the future.

Glaesserella parasuis (G. parasuis) causes Glässer’s disease and systemic inflammatory responses in the host. The currently available therapies have limited efficacy and fail to achieve a balance between anti-inflammatory and antibacterial effects. In this study, we investigated the effects of baicalin, amoxicillin, and probenecid on blood biochemical parameters, routine blood indicators, survival rate, bacterial burden, and pathological tissue damage in G. parasuis-challenged mice. Treatment with baicalin, amoxicillin, and probenecid significantly modified the blood biochemical parameters and routine blood test indicators, increased the survival rate, attenuated the bacterial burden, and alleviated pathological tissue damage in G. parasuis-challenged mice. Treatment with baicalin, amoxicillin, and probenecid also increased the number of CD3⁺, CD3⁺CD4⁺, and CD3⁺CD8⁺ T cells as measured by flow cytometry, and restored the intensity of the CD3, CD4, and CD8 protein expression in the blood vessels of G. parasuis-challenged mice by immunohistochemistry. These compounds reduced interleukin 1β (IL-1β), IL-18, tumor necrosis factor alpha (TNF-α), and high mobility group box 1 protein (HMGB1) expression in the spleen of G. parasuis-challenged mice. Furthermore, baicalin, amoxicillin, and probenecid inhibited activation of the family pyrin domain containing 3 (NLRP3) inflammasome and apoptosis in the spleen of G. parasuis-challenged mice. This study showed the important roles of baicalin, amoxicillin, and probenecid in the modulation of the inflammatory response of Glässer’s disease. The findings might provide new strategies for combination therapy using antibiotics and anti-inflammatory drugs to control G. parasuis infection.

Glaesserella parasuis (G. parasuis) can cause peritonitis in piglets. However, the pathogenesis of peritonitis remains unclear. Baicalin has been shown to possess anti-inflammatory and anti-oxidant functions. The aim of this study was to investigate the role of the PANX-1/P2X7 axis and the P2Y6 signaling pathway in peritonitis induced by G. parasuis and the effect of baicain on the PANX-1/P2X7 axis and P2Y6 pathway activation triggered by G. parasuis. A G. parasuis serovar 5 isolate SH0165 strain was obtained from the lungs of commercially produced pigs which had the typical symptoms of Glässer’s disease, namely arthritis, fibrinous polyserositis, hemorrhagic pneumonia, and meningitis. Then, 35 piglets were randomly divided into five groups, each group containing seven piglets. The groups consisted of a negative control group, an infection group, a 25 mg/kg baicalin group, a 50 mg/kg baicalin group, and a 100 mg/kg baicalin group. The results showed that G. parasuis could promote PANX-1/P2X7 axis and P2Y6 activation; induce NLRP3/caspase-1, IL-1β and IL-18 expression; trigger PLC/PKC and MLCK/MLC signaling activation; attenuate the expression of tight junction proteins ZO-1, E-cadherin, Occludins, and claudin 1; and stimulate CD14, CD24, CD36, CD47, and CD91 expression in the peritoneum as measured via Western blot (p < 0.01; PLC, p < 0.05). Baicalin could significantly inhibit PANX-1/P2X7 axis, P2Y6, and NLRP3/caspase-1 activation; reduce IL-1β and IL-18 expression; attenuate PLC/PKC and MLCK/MLC activation; promote ZO-1, E-cadherin, occludins, and claudin 1 expression; and reduce CD14, CD24, CD36, CD47, and CD91 expression in the peritoneum induced by G. parasuis as measured via Western blot. Our results deepen the understanding of the mechanism of peritonitis triggered by G. parasuis and provide some novel potential methods of controlling G. parasuis infection.