Acute alcoholic liver injury (AALI) remains a significant global health concern, primarily driven by oxidative stress. This study investigated the protective mechanisms of Weizmannia coagulans BC99 against alcohol-induced oxidative stress using a dual model in rats and Caenorhabditis elegans. In rats, excessive alcohol was predominantly metabolized via the CYP2E1 pathway, leading to severe oxidative stress. However, intervention with BC99 suppressed CYP2E1 expression and enhanced antioxidant enzyme activities through the Nrf2/SKN-1 pathway, thereby alleviating oxidative stress. Additionally, BC99 treatment elevated glutamate and aspartate levels while reducing glycerate and glucose, which collectively increased glutathione levels and mitigated oxidative stress triggered by glucose metabolism disorders. In C. elegans, BC99 reduced excessive ROS by upregulating Nrf2/skn-1, daf-16, and their downstream antioxidant genes, consequently alleviating the biotoxicity associated with alcohol-induced oxidative damage. The protective effects of BC99 were markedly diminished in the skn-1 mutant (GR2245) and daf-16 mutant (CF1038), further confirming the pivotal roles of SKN-1 and DAF-16 pathways in BC99-mediated antioxidant protection. Taken together, these findings reveal that BC99 mitigates alcohol-induced oxidative stress by activating the Nrf2/SKN-1 pathway and regulating liver metabolites to eliminate excess ROS, thereby providing a theoretical basis for the application of probiotics in preventing acute alcoholic liver injury.

The emergence of multidrug-resistant (MDR) Proteus mirabilis poses a significant threat in porcine farming and public health, highlighting the need for alternative biocontrol agents. This study aimed to isolate and characterize a lytic bacteriophage with therapeutic potential against MDR P. mirabilis. Using the clinical MDR P. mirabilis strain Pm 07 as host, a bacteriophage, vB_Pmc_P-07 (P-07), was successfully isolated from fecal and sewage samples via an enrichment protocol. Phage P-07 forms plaques surrounded by a distinct translucent “halo,” suggesting the production of depolymerase. It achieved high titers of up to 1.40 × 10⁸ PFU/mL and exhibited a narrow host range, high stability across a broad range of temperatures (40–60 °C) and pH (4–12), as well as considerable anti-biofilm activity. An optimal multiplicity of infection (MOI) of 0.001 was determined. Whole-genome sequencing revealed a linear double-stranded DNA genome of 58,582 bp with a GC content of 46.91%, encoding 63 open reading frames. Crucially, no virulence or antibiotic resistance genes were detected, supporting its safety profile. Phylogenetic analysis classified P-07 within the Casjensviridae family, closely related to phages PM87 and pPM01. These findings indicate that phage P-07 is a novel, safe, and effective lytic phage with strong potential as a biocontrol agent against biofilm-forming MDR P. mirabilis in swine.

The increased emission and accumulation of microplastics pose a severe threat to humans and the environment. As effective biological agents for alleviating the effects of microplastics, the mechanism of action of probiotics remains unclear. In this study, based on the successful establishment of a reproductive virulence model of Caenorhabditis elegans (C. elegans), we explored the effect and mechanism of Weizmannia coagulans CGMCC 9951 (W. coagulans CGMCC 9951) on the reproductive toxicity of C. elegans. Our results showed that the gonad area and the number of offspring increased but the number of germ cells undergoing apoptosis decreased by 14% and 24% in C. elegans, after CGMCC 9951 treatments. Antioxidant test results showed that CGMCC 9951 increased the activity of Superoxide Dismutase (SOD), Catalase (CAT), and the content of Glutathione (GSH) in C. elegans. In addition, it was found by qPCR and mutagenesis experiments verified that CGMCC 9951 alleviated reproductive toxicity through the DNA checkpoint signaling pathway. Our findings suggested that CGMCC 9951 could alleviate the reproductive toxicity of polystyrene microplastics in C. elegans by enhancing antioxidant capacity and inhibiting DNA damage checkpoint signaling pathway. The above results suggest that probiotics can be used as a potential approach to alleviate the reproductive toxicity induced by polystyrene microplastics in humans.

Butyrate, a short-chain fatty acid derived from the gut microbiota, has been linked to depression through correlational studies; however, whether it might act as a sufficient downstream mediator of the antidepressant effects of a probiotic remains poorly understood. To explore this, a chronic unpredictable mild stress (CUMS) rat model was established to evaluate the potential antidepressant effects of Weizmannia coagulans BC99. Behavioral assessments included the sucrose preference test (SPT), forced swim test (FST), tail suspension test (TST), and open field test (OFT). In addition, 16S rRNA sequencing, serum metabolomics, and short-chain fatty acid (SCFA) profiling were performed. Levels of inflammatory cytokines (IL-1β, IL-6, IL-4, and LPS) and brain-derived neurotrophic factor (BDNF) were measured in serum, hippocampus, and colon by ELISA. An independent sodium butyrate supplementation experiment was conducted to test functional sufficiency, and hippocampal BDNF/TrkB/CREB signaling was assessed by Western blotting. Treatment with BC99 was associated with alleviation of CUMS-induced depressive-like behaviors, increased butyrate levels, reduced neuroinflammation (IL-1β, IL-6, LPS, and IL-4), and restored hippocampal BDNF levels. BC99 also enriched butyrate-producing bacterial taxa (e.g., Lactobacillus, Bifidobacterium, Faecalibaculum) and normalized tryptophan and sphingolipid metabolism. Notably, sodium butyrate alone recapitulated several of the behavioral and anti-inflammatory effects observed with BC99 and, as shown by Western blot, partially restored hippocampal BDNF/TrkB/CREB signaling, which was impaired in CUMS rats. Together, these findings suggest that butyrate may be associated with the antidepressant effects of W. coagulans BC99, potentially acting through suppression of neuroinflammation and activation of the BDNF pathway. Our results support further investigation of butyrate-enhancing strategies as a nutritional approach for depression.