Exploration of Lactiplantibacillus plantarum P101 ameliorated the alcohol-induced testicular dysfunction based on metabolome analysis.

The decline in male sperm quality caused by multiple factors has become a widespread concern. Alcohol excessive consumption is one of the factors that induce testicular dysfunction. Testicular dysfunction caused by alcohol abuse is related to oxidative stress and inflammation. Probiotics can ameliorate alcohol-induced testicular dysfunction. However, the specific mechanism is not explicit. This study aimed to elucidate the underlying mechanism by which Lactiplantibacillus plantarum P101 ameliorates the alcohol-induced testicular dysfunction. The model of alcohol-induced testicular dysfunction in C57B/6 male mice was established according to the National Institute on Alcohol Abuse and Alcoholism, and Lactiplantibacillus plantarum P101 supplementation was orally administered to mice during the experiment. The results showed that Lactiplantibacillus plantarum P101 promoted androgen production, reduced testis inflammation, and improved testis antioxidant capacity, thereby improving sperm quality and sperm motility and ultimately ameliorating alcohol-induced testicular disorder. Three key metabolite pathways and six key metabolites were identified by metabolome analysis.

Polystyrene nanoplastics exacerbated Pb-induced liver toxicity in mice.

Nanoplastics are widely distributed in the environment and can adsorb heavy metals, which poses a potential threat to human health through food chain. It is necessary to assess the combined toxicity of nanoplastics and heavy metals. The adverse effect of Pb and nanoplastics on liver, single or in combination, was evaluated in this study. The results showed that the Pb content in co-exposure group of nanoplastics and Pb (PN group) was higher than the group exposed to Pb alone (Pb group). And more severe inflammatory infiltration was observed in liver sections of PN group. The level of inflammatory cytokines and malondialdehyde were increased, while the superoxide dismutase activity was decreased in liver tissues of PN group. Moreover, the gene expression level of nuclear factor-erythroid 2-related factor 2, nicotinamide adenine dinucleotide phosphate:quinine oxidoreductase 1 and catalase, which is related to antioxidation, was downregulated. And the expression level of cleaved-Caspase9 and cleaved-Caspase3 were increased. However, with the supplementation of oxidative stress inhibitor N-Acetyl-L-cysteine, liver damage shown in PN group was evidently alleviated. In summary, nanoplastics evidently exacerbated the deposition of Pb in liver and potentially aggravated the Pb-induced liver toxicity by activating oxidative stress.

Male reproductive toxicity of polystyrene microplastics: Study on the endoplasmic reticulum stress signaling pathway.

Microplastics (MPs) have raised health concerns in public for its potential reproductive toxicity. In this study, we subjected the Kunming mice to 0.01, 0.1 and 1.0 mg/day polystyrene MPs (10 µm, PS-MPs) for 35 days, aiming to investigate the relevant male reproductive toxicity and latent molecular mechanism. The results showed the decreased sperm counts and motility, while the elevated sperm abnormality in PS-MPs-exposed mice. Testicular H&E staining displayed the vacuolization, atrophy, and even shedding of germ cells in seminiferous tubule. And the testosterone content in serum also decreased with PS-MPs treatment. Moreover, molecular analysis indicated that PS-MPs upregulated the expression trait factors for ERS (e.g., immunoglobulin-binding protein [BIP], inositol-requiring protein 1α [IRE1α], X-box-binding protein 1 splicing [XBP1s], Jun kinase [JNK], and the transcription of CCAAT/enhancer-binding protein (C/EBP) homologous protein [CHOP]) and downstream apoptotic modulator (e.g., Caspase-12, -9, and -3) in the testis. The steroidogenic acute regulatory protein (StAR), the testosterone synthetic initiator, was also downregulated. With the supplementation of ERS inhibitor, the MPs-induced testicular damage and decreased testosterone were improved to almost normal level. Overall, this study suggested that PS-MPs generate reproductive toxicity possibly via activating ERS and apoptosis signaling pathway.

Micro(nano)plastics in food system: potential health impacts on human intestinal system.

Micro(nano)plastics (MNPs) in human food system have been broadly recognized by researchers and have drawn an increasing public attention to their potential health risks, particularly the risk to the intestinal system regarding the long-term exposure to MNPs through food consumption. This study aims to review the environmental properties (formation and composition) of MNPs and MNPs pollution in human food system following the order of food production, food processing and food consumption. The current analytic and identical technologies utilized by researchers are also summarized in this review. In fact, parts of commonly consumed food raw materials, processed food and the way to take in food all become the possible sources for human MNPs ingestion. In addition, the available literatures investigating MNPs-induced intestinal adverse effect are discussed from in vitro models and in vivo mammalian experiments, respectively. Particle translocation, cytotoxicity, damaged gut barrier, intestinal inflammation as well as microbial alteration are mostly reported. Moreover, the practical remediation strategies for MNPs pollution are also illustrated in the last section. This review is expected to provide a research insight for foodborne MNPs and arouse more public awareness of MNPs pollution in food and potential risk for human intestinal health.

Microplastics-perturbed gut microbiota triggered the testicular disorder in male mice: Via fecal microbiota transplantation.

Microplastics (MPs), an emerging environmental pollutant, have been clarified to induce testicular disorder in mammals. And the current studies have delineated a correlation between gut microbiota and male reproduction. However, it's still unclear whether gut microbiota gets involved in MPs-induced reproductive toxicity. In this work, we constructed a mouse model drinking 5 µm polystyrene-MPs (PS-MPs) at the concentrations of 100 µg/L and 1000 µg/L for 90 days. Evident histological damage, spermatogenetic disorder and hormones synthesis inhibition were observed in PS-MPs exposed mice. With fecal microbiota transplantation (FMT) trial, the recipient mice exhibited gut microbial alteration, and the elevated abundance of Bacteroides and Prevotellaceae_UCG-001 were positively correlated with testicular disorder according to spearman correlation analysis. Mechanistically, increased proportion of pro-inflammatory bacteria may drive translocation of T helper 17 (Th17) cells, resulting in overproduced interleukin (IL)-17 A and downstream inflammatory response in both the mice exposed to PS-MPs and corresponding recipient mice. In summary, our findings revealed the critical role of gut microbiota in PS-MPs-induced reproductive toxicity, and tried to elucidate the underlying mechanism of gut microbial dysregulation-mediated IL-17 A signaling pathway. Furthermore, this study also provides the research basis for gut microbiota-targeted treatment of male infertility in the future.

Polystyrene microplastics exacerbated liver injury from cyclophosphamide in mice: Insight into gut microbiota.

Microplastics (MPs) have infiltrated human food system globally, and the latent health risks have been well-described. However, the impact of pre-consumed MPs on liver resistance to foreign robust stimuli remains unclear. In this study, we developed a mouse model drinking roughly 18 and 180 µg/kg/day polystyrene MPs for 90 days, then intraperitoneally injected mice with 80 mg/kg cyclophosphamide (CTX) to investigate whether chronic pre-exposure to MPs aggravates hepatoxicity induced by CTX. Slight liver injury was found in single CTX-treated mice, while more significant liver histopathological damage, inflammation and oxidative stress elicited by CTX were observed in pre-drinking MPs mice. Moreover, chronic exposure of MPs induced remarkable colonic impairments (e.g., leaky gut, mild inflammation and repressed antioxidant activity) as well as gut microbiota perturbation, which manifested positive association with aggravated hepatotoxicity via spearman correlation analysis. Fecal microbiota transplantation (FMT) trail was conducted to ulteriorly demonstrate the critical role of MPs-altered gut bacteria in exaggerated liver susceptibility to CTX stimulation. In conclusion, our study provided an insight that the adverse impact of MPs could be best revealed when animals suffering attack from hazardous substance. It also contributes to comprehensive assessment of health risk from environmentally pervasive MPs.