Disruption of Intestinal Homeostasis Through Altered Responses of the Microbial Community, Energy Metabolites, and Immune System in Zebrafish After Chronic Exposure to DEHP

Trophic transfer induced gut inflammation, dysbiosis, and inflammatory pathways in zebrafish via Artemia franciscana: A differential analysis of nanoplastic toxicity

Rising glbal population and plastic consumption have caused a dramatic increase in plastic waste, leading to micro- and nanoplastic ingestion by aquatic organisms and subsequent bioaccumulation in their tissues. This transfer to higher trophic levels raises nanoplastic concentrations and bioavailability, potentially harming organisms' health and development. This poses a risk to human health via seafood. To address these issues, this study assesses the toxicological impacts of nanoplastics (NPs) on brine shrimp (Artemia franciscana) and their trophic transfer to zebrafish. The research unveiled concentration-dependent bioaccumulation of NPs in zebrafish and Artemia franciscana (A. franciscana). Polystyrene nanoplastics (PS-NPs) exhibited higher accumulation in A. franciscana whereas PP-NPs showed greater accumulation in zebrafish gut. Histopathological analysis under PS-NPs exposure revealed significant tissue alterations, indicative of inflammatory responses and impaired mucosal barrier integrity. Gene expression analyses confirmed these findings, showing activation of the P38-MAPK pathway by PS-NPs, which correlated with increased inflammatory cytokines. Additionally, PE-NPs activated the JNK-MAPK pathway, while PP-NPs exposure triggered the NOD-like receptor signaling pathway. Moreover, the composition of gut microbiota shifted to a dysbiotic state, characterized by an increase in pathogenic bacteria in the PS-NPs and PP-NPs groups, elevating the risk of developing Inflammatory Bowel Disease (IBD). PS-NPs were regarded as the most toxic due to their lower stability and higher aggregation tendencies, followed by PP-NPs and PE-NPs. Taken together, the overall study highlighted the complex interactions between NPs, gut microbiota, and host health, emphasizing the importance of thoroughly assessing the ecological and physiological impacts of nanoplastic pollution.

Di-(2-ethylhexyl) phthalate and its metabolites research trend: a bibliometric analysis

Di-(2-ethylhexyl) phthalate (DEHP) is one of the most widely used plasticizers. Many studies focus on the impact of continuous exposure to DEHP on humans and ecosystems. In this study, the bibliometric analysis of DEHP and its metabolites research was conducted to assess the research performances, hotspot issues, and trends in this field. The data was retrieved from a Web of Science Core Collection online database. VOSviewer 1.6.18 was used to analyze. A total of 4672 publications were collected from 1975 to 2022 October 21. The number of publications and citations increased annually in the last decades. China had the largest number of publications, and the USA had the highest co-authorship score. The most productive and most frequently cited institutions were the Chinese Academy of Sciences and the Centers for Disease Control & Prevention (USA), respectively. The journal with the most publications was the Science of Total Environment, and the most cited one was the Environmental Health Perspectives. The most productive and cited author was Calafat A. M. (USA). The most cited reference was "Phthalates: toxicology and exposure." Four hotspot issues were as follows: influences of DEHP on the organisms and its possible mechanisms, assessment of DEHP exposure to the human and its metabolism, dynamics of DEHP in external environments, and indoor exposure of DEHP and health outcomes. The research trends were DNOP, preterm birth, gut microbiota, microplastics, lycopene, hypertension, and thyroid hormones. This study can provide researchers with new ideas and decision-makers with reference basis to formulate relevant policies.

Effects of BBIBP-CorV vaccine on gut microbiota and short-chain fatty acids in mice exposed to bis (2-ethylhexyl) phthalate and dioctyl terephthalate

As the COVID-19 pandemic has progressed, increasing evidences suggest that the gut microbiota may play a crucial role in the effectiveness of SARS-CoV-2 vaccine. Thus, this study was aimed at investigating the influence of SARS-CoV-2 vaccine on the gut microbiota and short-chain fatty acids (SCFAs) of organisms exposed to environmental contaminants, i.e., plasticizers: phthalate esters. We found that in mice, exposure to dioctyl terephthalate (DOTP) and bis -2-ethylhexyl phthalate (DEHP) decreased the blood glucose level and white fat weight, induced inflammatory responses, caused damage to liver and intestinal tissues, and disrupted the gut microbiota composition and SCFAs metabolism. Specifically, the Bacteroidetes phylum was positively correlated with BBIBP-CorV vaccine, while acetic acid was negatively associated with the vaccine. Interestingly, the BBIBP-CorV vaccine somewhat alleviated tissue inflammation and reduced the contents of acetic acid and propionic acid in mice exposed to DEHP and DOTP. These findings were confirmed by a fecal microbiota transplantation assay. Overall, this study revealed that exposure to DEHP and DOTP adversely affects the gut microbiota and SCFAs, while the BBIBP-CorV vaccine can protect mice against these effects. This work highlighted the relationship between BBIBP-CorV vaccination, gut microbiome composition, and responses to plasticizers, which may facilitate the development and risk assessment of SARS-CoV-2 vaccines and environmental contaminants on microbiota health.

Understanding the links between micro/nanoplastics-induced gut microbes dysbiosis and potential diseases in fish: A review

At present, the quantity of micro/nano plastics in the environment is steadily rising, and their pollution has emerged as a global environmental issue. The tendency of their bioaccumulation in aquatic organisms (especially fish) has intensified people's attention to their persistent ecotoxicology. This review critically studies the accumulation of fish in the intestines of fish through active or passive intake of micro/nano plastics, resulting in their accumulation in intestinal organs and subsequent disturbance of intestinal microflora. The key lies in the complex toxic effect on the host after the disturbance of fish intestinal microflora. In addition, this review pointed out the characteristics of micro/nano plastics and the effects of their combined toxicity with adsorbed pollutants on fish intestinal microorganisms, in order to fully understand the characteristics of micro/nano plastics and emphasize the complex interaction between MNPs and other pollutants. We have an in-depth understanding of MNPs-induced intestinal flora disorders and intestinal dysfunction, affecting the host's systemic system, including immune system, nervous system, and reproductive system. The review also underscores the imperative for future research to investigate the toxic effects of prolonged exposure to MNPs, which are crucial for evaluating the ecological risks posed by MNPs and devising strategies to safeguard aquatic organisms.

Biotoxicity responses of zebrafish in environmentally relevant concentration of di (2-ethylhexyl) phthalate

As an emerging environmental contaminant, di (2-ethylhexyl) phthalate (DEHP) is widely present in the aquatic environment, however, the effects and underlying mechanisms of DEHP on the aquatic organisms are poorly understood. This study systematically investigated the ecotoxicity induced by chronic exposure to environmental relevant concentrations of DEHP (0.03 mg/L, 0.1 mg/L, and 0.3 mg/L) on zebrafish brain. Results indicated that DEHP exposure significantly increased the levels of ROS and disturbance of the antioxidant enzymes activities in the brain, which may further enhance lipid peroxidation and DNA damage. Furthermore, acetylcholinesterase activity was first stimulated and inhibited by exposure to DEHP, and the antioxidant and apoptosis related genes were mainly upregulated. Risk assessment indicated that the ecotoxicity of DEHP on the zebrafish showed an "enhancement-reduction" trend as the exposure time was prolonged. Overall, these results provided new insights and useful information to ecological risk assessment and environmental management of DEHP pollution.

Disrupting the gut microbiota/metabolites axis by Di-(2-ethylhexyl) phthalate drives intestinal inflammation via AhR/NF-κB pathway in mice

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer known for its environmental endocrine-disrupting properties, posing potential risks to various organs. However, the precise impact of DEHP on intestinal health and its contribution to the initiation of intestinal inflammation remains elucidated. This study aims to investigate the underlying mechanisms of DEHP-induced intestinal inflammation in mice, specifically focusing on the complex interplay between the gut microbiota-metabolite axis and associated pathophysiological alterations. Our findings showed that DEHP-induced damage of multiple organs systemically, as indicated by abnormal liver and kidney biochemical markers, along with a disrupted ileum morphology. Additionally, DEHP exposure disrupted gut barrier function, causing intestinal inflammation characterized by bacterial translocation and alterations in defense and inflammation-related gene expressions. Moreover, 16S rRNA analysis suggested that DEHP-induced gut microbial remodeling is characterized by an upregulation of detrimental bacteria (Erysipelotrichaceae) and a downregulation of beneficial bacteria (Muribaculaceae, Ruminococcaceae, and Lachnospiraceae). Metabolomics analysis revealed DEHP perturbed gut metabolic homeostasis, particularly affecting the degradation of aromatic compounds, which generated an aberrant activation of the AhR and NF-κB, subsequently causing intestinal inflammation. Consequently, our results elucidate the mechanistic link between disrupted gut microbiota and metabolome and the initiation of DEHP-induced intestinal inflammation, mediated through the AhR/NF-κB signaling pathway.

Effects of Intestinal Microbiota on the Biological Transformation of Arsenic in Zebrafish: Contribution and Mechanism

Both the gut microbiome and their host participate in arsenic (As) biotransformation, while their exact roles and mechanisms in vivo remain unclear and unquantified. In this study, as3mt-/- zebrafish were treated with tetracycline (TET, 100 mg/L) and arsenite (iAsIII) exposure for 30 days and treated with probiotic Lactobacillus rhamnosus GG (LGG, 1 × 108 cfu/g) and iAsIII exposure for 15 days, respectively. Structural equation modeling analysis revealed that the contribution rates of the intestinal microbiome to the total arsenic (tAs) and inorganic As (iAs) metabolism approached 44.0 and 18.4%, respectively. Compared with wild-type, in as3mt-/- zebrafish, microbial richness and structure were more significantly correlated with tAs and iAs, and more differential microbes and microbial metabolic pathways significantly correlated with arsenic metabolites (P < 0.05). LGG supplement influenced the microbial communities, significantly up-regulated the expressions of genes related to As biotransformation (gss and gst) in the liver, down-regulated the expressions of oxidative stress genes (sod1, sod2, and cat) in the intestine, and increased arsenobetaine concentration (P < 0.05). Therefore, gut microbiome promotes As transformation and relieves As accumulation, playing more active roles under iAs stress when the host lacks key arsenic detoxification enzymes. LGG can promote As biotransformation and relieve oxidative stress under As exposure.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Effects of methomyl on the intestinal microbiome and hepatic transcriptome of tilapia, and the modifying effects of mint co-culture

Methomyl (MET) is an oxime carbamate insecticide that can contaminate aquatic systems resulting in toxicological effects. It can harm some fish species possibly through the anti-oxidative, phagosome pathway. Mint is one of the most widely herbal plants exhibiting antioxidant activities. In this study, we investigated the impact of MET on the antioxidant system of Oreochromis niloticus in presence of mint as a floating bed. Results revealed that the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase, and glutathione S-transferase significantly decreased and the GSH content significantly increased in the intestine. The hepatic peroxisome proliferator-activated receptor (PPAR) signalling pathway, carbon metabolism, renal phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK) signalling pathway, and phagosomes were significantly affected. Upon long-term exposure, circadian rhythm and phagosomes were enriched in the liver and kidney. However, mint increased the enriched pathways of Toll-like receptor, PPAR, p53, NF-kappa B, MAPK, oestrogen, and B cell receptor signalling pathways. MET with different concentrations destroyed the balance of gut microbiota, mint decreased Verrucomicrobia and Akkermansia for the maintenance resulted from MET. Cetobacterium had a positive impact on total nitrogen (TN), chemical oxygen demand (CODMn), and glutathione reductase (GR), while Akkermansia had a positive impact on feed conversion ratio (FCR), SOD and CAT, and the abundance of both decreased due to MET exposure. High mint density removed more concentrations of nitrogen and phosphorus in the tilapia cultivation wastewater. Therefore, planting with mint can alleviate the toxicological effects produced by MET, shape the intestinal microbiota, and strengthen the connection between water quality and the metabolic parameters.

Evodiamine alleviates DEHP-induced hepatocyte pyroptosis, necroptosis and immunosuppression in grass carp through ROS-regulated TLR4 / MyD88 / NF-κB pathway

Di (2-ethylhexyl) phthalate (DEHP) is a neuroendocrine disruptor that can cause multi-tissue organ damage by inducing oxidative stress. Evodiamine (EVO) is an indole alkaloid with anti-inflammatory, antitumor, and antioxidant pharmacological activity. In this manuscript, the effects of DEHP and EVO on the pyroptosis, necroptosis and immunology of grass carp hepatocytes (L8824) were investigated using DCFH-DA staining, PI staining, IF staining, AO/EB staining, LDH kit, qRT-PCR and protein Western blot. The results showed that DEHP exposure upregulated reactive oxygen species (ROS) levels, promoted the expression of TLR4/MyD88/NF-κB pathway, increased the expression of genes involved in cell pyroptosis pathway (LDH, NLRP3, ASC, caspase1, IL-1β, IL-18 and GSDMD) and necroptosis-related genes (RIPK1, RIPK3 and MLKL). The expression of DEHP can also affect immune function, which can be demonstrated by variationsin the activation of antimicrobial peptides (LEAP2, HEPC, and β-defensin) and inflammatory cytokines (TNF-α, IL-2, IL-6 and IL-10). EVO regulates cellular antioxidant capacity by inhibiting ROS burst, reduces DEHP-induced cell pyroptosis and necroptosis to some extent, and restores cellular immune function, after co-exposure with EVO. The TLR4 pathway was inhibited by the co-treatment of TLR4 inhibitor TLR-IN-C34 and DEHP, which attenuated the expression of cell pyroptosis, necroptosis, and immunosuppression. Thus, DEHP induced pyroptosis, necroptosis and abnormal immune function in L8824 cells by activating TLR4/MyD88/NF-κB pathway. In addition, EVO has a therapeutic effect on DEHP-induced toxic injury. This study further provides a theoretical basis for the risk assessment of plasticizer DEHP on aquatic organisms.

Guided Metabolic Detoxification Program Supports Phase II Detoxification Enzymes and Antioxidant Balance in Healthy Participants

Adequate antioxidant supply is essential for maintaining metabolic homeostasis and reducing oxidative stress during detoxification. The emerging evidence suggests that certain classes of phytonutrients can help support the detoxification process by stimulating the liver to produce detoxification enzymes or acting as antioxidants that neutralize the harmful effects of free radicals. This study was designed to examine the effects of a guided 28-day metabolic detoxification program in healthy adults. The participants were randomly assigned to consume a whole food, multi-ingredient supplement (n = 14, education and intervention) or control (n = 18, education and healthy meal) daily for the duration of the trial. The whole food supplement contained 37 g/serving of a proprietary, multicomponent nutritional blend in the form of a rehydratable shake. Program readiness was ensured at baseline using a validated self-perceived wellness score and a blood metabolic panel, indicating stable emotional and physical well-being in both groups. No significant changes or adverse effects were found on physical or emotional health, cellular glutathione (GSH) and the GSH:GSSG ratio, porphyrin, and hepatic detoxification biomarkers in urine. The intervention was positively associated with a 23% increase in superoxide dismutase (p = 0.06) and a 13% increase in glutathione S-transferase (p = 0.003) activities in the blood. This resulted in a 40% increase in the total cellular antioxidant capacity (p = 0.001) and a 13% decrease in reactive oxygen species (p = 0.002) in isolated PBMCs from participants in the detoxification group. Our findings indicate that consuming a whole food nutritional intervention as a part of the guided detoxification program supported phase II detoxification, in part, by promoting enhanced free radical scavenging and maintaining redox homeostasis under the body's natural glutathione recycling capacity.

Bacteriophage-based techniques for elucidating the function of zebrafish gut microbiota

Bacteriophages (or phages) are unique viruses that can specifically infect bacteria. Since their discovery by Twort and d'Herelle, phages with bacterial specificity have played important roles in microbial regulation. The intestinal microbiota and host health are intimately linked with nutrient, metabolism, development, and immunity aspects. However, the mechanism of interactions between the composition of the microbiota and their functions in maintaining host health still needs to be further explored. To address the lack of methodology and functions of intestinal microbiota in the host, we first proposed that, with the regulations of special intestinal microbiota and applications of germ-free (GF) zebrafish model, phages would be used to infect and reduce/eliminate the defined gut bacteria in the conventionally raised (CR) zebrafish and compared with the GF zebrafish colonized with defined bacterial strains. Thus, this review highlighted the background and roles of phages and their functional characteristics, and we also summarized the phage-specific infection of target microorganisms, methods to improve the phage specificity, and their regulation within the zebrafish model and gut microbial functional study. Moreover, the primary protocol of phage therapy to control the intestinal microbiota in zebrafish models from larvae to adults was recommended including phage screening from natural sources, identification of host ranges, and experimental design in the animal. A well understanding of the interaction and mechanism between phages and gut bacteria in the host can potentially provide powerful strategies or techniques for preventing bacteria-related human diseases by precisely regulating in vitro and in vivo, which will provide novel insights for phages' application and combined research in the future. KEY POINTS: • Zebrafish models for clarifying the microbial and phages' functions were discussed • Phages infect host bacteria with exquisite specificity and efficacy • Phages can reduce/eliminate the defined gut bacteria to clarify their function.

Intestinal bacteria diversity of suckermouth catfish (Pterygoplichthys pardalis) in the Cd, Hg, and Pb contaminated Ciliwung River, Indonesia

The contamination of aquatic environments with heavy metals poses a serious threat to fish, potentially leading to diseases or even death. Therefore, there is an urgent need for studies to investigate the adaptability of fish in heavy metal-contaminated environments. Several studies have explored the adaptability of suckermouth catfish (P. pardalis) to survive in the contaminated Ciliwung River. The findings obtained showed that the presence of intestinal bacteria helped these fish overcome the heavy metals in their intestines, thereby enabling the fish to survive. Analysis using the Next Generation Sequencing (NGS) technology has succeeded in identifying diversity of these bacteria in P. pardalis living in the Ciliwung River, which contaminated with Cd (0.3-1.6 ppm in the water & 0.9-1.6 ppm in the sediment), Hg (0.6-2 ppm in the water & 0.6-1.8 ppm in the sediment), and Pb (59.9-73.8 ppm in the water & 26.1-58.6 ppm in the sediment). Diversity index of intestinal bacteria in P. pardalis was relatively high, but it had a negative correlation with the presence of these contaminants. Actinobacteria, Firmicutes, and Proteobacteria were abundant in the intestines of P. pardalis from the upstream to downstream of the river, with an overall abundance range of 15-48%. Furthermore, Mycobacterium along with 6 other genera were identified as core intestinal bacteria. The presence of these bacterial communities in all the samples affected their survival in heavy metals-contaminated rivers. The fish's adaptability to live in this harsh environment indicated that it has the potential to be utilized as a bioremediator of heavy metals in river sediments.

Phthalate derivative DEHP disturbs the antiproliferative effect of camptothecin in human lung cancer cells by attenuating DNA damage and activating Akt/NF-κB signaling pathway

Plasticizers/phthalates play a facilitating role in the development of cancer and help the tumor to grow and metastasize. Camptothecin (CPT) and its derivatives are known to have anticancer properties of inhibiting cell growth, promoting cell apoptosis, and increasing autophagy. Therefore, in this study, we investigated whether the presence of di(2-ethylhexyl) phthalate (DEHP) could hinder apoptosis and autophagy caused by CPT in non-small cell lung cancer (NSCLC) cells. We found that DEHP interferes with CPT-induced apoptosis and autophagy and increases the prosurvival pathway by reducing the DNA damage marker γ-H2AX and activating the Akt and NF-κB pathways. Furthermore, we also confirmed that combining DEHP with 3-MA has additive effects in inhibiting autophagy and apoptosis in NSCLC cells. Taken together, our findings show that DEHP could affect CPT-induced anticancer treatment and provide evidence to show that DEHP induces chemoresistance in CPT-based chemotherapy.

Epigenetics and mitochondrial dysfunction insights into the impact of the progression of non-alcoholic fatty liver disease

A metabolic problem occurs when regular functions of the body are disrupted due to an undesirable imbalance. Nonalcoholic fatty liver disease (NAFLD) is considered as one of the most common in this category. NAFLD is subclassified and progresses from lipid accumulation to cirrhosis before advancing to hepatocellular cancer. In spite of being a critical concern, the standard treatment is inadequate. Metformin, silymarin, and other nonspecific medications are used in the management of NAFLD. Aside from this available medicine, maintaining a healthy lifestyle has been emphasized as a means of combating this. Epigenetics, which has been attributed to NAFLD, is another essential feature of this disease that has emerged as a result of several sorts of research. The mechanisms by which DNA methylation, noncoding RNA, and histone modification promote NAFLD have been extensively researched. Another organelle, mitochondria, which play a pivotal role in biological processes, contributes to the global threat. Individuals with NAFLD have been documented to have a multitude of alterations and malfunctioning. Mitochondria are mainly concerned with the process of energy production and regulation of the signaling pathway on which the fate of a cell relies. Modulation of mitochondria leads to elevated lipid deposition in the liver. Further, changes in oxidation states result in an impaired balance between the antioxidant system and reactive oxygen species directly linked to mitochondria. Hence mitochondria have a definite role in potentiating NAFLD. In this regard, it is essential to consider the role of epigenetics as well as mitochondrial contribution while developing a medication or therapy with the desired accuracy.

Exploring Next Generation Probiotics for Metabolic and Microbiota Dysbiosis Linked to Xenobiotic Exposure: Holistic Approach

Variation of gut microbiota in metabolic diseases seems to be related to dysbiosis induced by exposure to multiple substances called Microbiota Disrupting Chemicals (MDCs), which are present as environmental and dietary contaminants. Some recent studies have focused on elucidating the alterations of gut microbiota taxa and their metabolites as a consequence of xenobiotic exposures to find possible key targets involved in the severity of the host disease triggered. Compilation of data supporting the triad of xenobiotic-microbiota-metabolic diseases would subsequently allow such health misbalances to be prevented or treated by identifying beneficial microbe taxa that could be Next Generation Probiotics (NGPs) with metabolic enzymes for MDC neutralisation and mitigation strategies. In this review, we aim to compile the available information and reports focused on variations of the main gut microbiota taxa in metabolic diseases associated with xenobiotic exposure and related microbial metabolite profiles impacting the host health status. We performed an extensive literature search using SCOPUS, Web of Science, and PubMed databases. The data retrieval and thorough analyses highlight the need for more combined metagenomic and metabolomic studies revealing signatures for xenobiotics and triggered metabolic diseases. Moreover, metabolome and microbiome compositional taxa analyses allow further exploration of how to target beneficial NGP candidates according to their alleged variability abundance and potential therapeutic significance. Furthermore, this holistic approach has identified limitations and the need of future directions to expand and integrate key knowledge to design appropriate clinical and interventional studies with NGPs. Apart from human health, the beneficial microbes and metabolites identified could also be proposed for various applications under One Health, such as probiotics for animals, plants and environmental bioremediation.

Polystyrene nanoparticles aggravate the adverse effects of di-(2-ethylhexyl) phthalate on different segments of intestine in mice

Emerging evidence indicates that nanoplastics (NPs) can transport organic pollutants such as di-(2-ethylhexyl) phthalate (DEHP) into organisms and induce adverse health effects. Nevertheless, the toxic effects of NPs combined with DEHP on mammalian intestine are still unclear. In this study, the C57BL6J mice were exposed to polystyrene nanoparticles (PSNPs), DEHP or them both for 30 days to determine their effects on different segments of intestine and the gut microbiota. As a result, DEHP alone or co-exposure to DEHP and PSNPs induced histological damages in all intestinal parts, mainly manifested as the decreased villus lengths, increased crypt depths in the duodenum, jejunum and ileum and decreased villus counts accompanied with decreased epithelial area in the colon. Moreover, decreased mucus coverage, down-regulated Muc2 expression levels as well as the broken tight junctions were observed in intestinal epithelium of mice, particularly obvious in the co-treatment groups. In general, as manifested by greater alterations in most of the parameters mentioned above, simultaneously exposed to PSNPs and DEHP seemed to induce enhanced toxic effects on intestine of mouse when compared with DEHP alone. Furthermore, the altered community composition of gut microbiota might at least partially contribute to these abnormalities. Overall, our results highlight the aggravated toxicity on different segments of intestine in mammalians due to co-exposure of PSNPs and DEHP, and these findings will provide valuable insights into the health risk of NPs and plastic additives.

Characterization of Gut Microbiome in the Mud Snail Cipangopaludina cathayensis in Response to High-Temperature Stress

Simple Summary

This study investigated the effects of high-temperature stress on the intestinal microbiome of Cipangopaludina cathayensis. High-temperature exposure significantly changed the intestinal microbiota structure of C. cathayensis. The relative abundance of putatively beneficial bacteria decreased, whereas the relative abundance of putatively pathogenic bacteria increased after thermal stress. Consistent with the trends of change in the intestinal microbiota, the high-temperature treatment inhibited some carbohydrate metabolism pathways and induced certain disease-related pathways. Thermal stress disrupts the homeostasis of gut microbiota, which may lead to disease outbreak in C. cathayensis.

Abstract

The mud snail Cipangopaludina cathayensis is a widely distributed species in China. Particularly in Guangxi province, mud snail farming contributes significantly to the economic development. However, global warming in recent decades poses a serious threat to global aquaculture production. The rising water temperature is harmful to aquatic animals. The present study explored the effects of high temperature on the intestinal microbiota of C. cathayensis. Snail intestinal samples were collected from the control and high-temperature groups on days 3 and 7 to determine the gut microbiota composition and diversity. Gut bacterial community composition was investigated using high-throughput sequencing of the V3–V4 region of bacterial 16S rRNA genes. Our results suggested that thermal stress altered the gut microbiome structure of C. cathayensis. At the phylum level, Proteobacteria, Bacteroidetes, and Firmicutes were dominant in C. cathayensis gut microbiota. The T2 treatment (32 ± 1 °C, day 7) significantly decreased the relative abundance of Firmicutes, Actinobacteria, and Deinococcus-Thermus. In T2, the abundance of several genera of putatively beneficial bacteria (Pseudomonas, Aeromonas, Rhodobacter, and Bacteroides) decreased, whereas the abundance of Halomonas—a pathogenic bacterial genus—increased. The functional prediction results indicated that T2 treatment inhibited some carbohydrate metabolism pathways and induced certain disease-related pathways (e.g., those related to systemic lupus erythematosus, Vibrio cholerae infection, hypertrophic cardiomyopathy, and shigellosis). Thus, high temperature profoundly affected the community structure and function of C. cathayensis gut microbiota. The results provide insights into the mechanisms associated with response of C. cathayensis intestinal microbiota to global warming.

Sub-lethal concentration of metamifop exposure impair gut health of zebrafish (Danio rerio)

Previous studies have demonstrated that sublethal metamifop exposures induce hepatic lipid metabolism disorder in zebrafish. Whether metamifop will cause adverse effects in zebrafish gut is unknown. In the present study, effects of metamifop on gut heath of zebrafish were investigated after sublethal concentration (0.025, 0.10 and 0.40 mg/L) exposure. Histopathology analysis showed that metamifop induced inflammation and reduction of goblet cells in the gut, indicating that gut health may be impaired. Metamifop exposure could reduce activities of digestive enzymes (lipase and alkaline phosphatase), indicating the capacity of lipid absorption were impaired. Meanwhile, the content of fatty acid-binding protein 2 (FABP2) and mRNA levels of related genes (apoa-1a, apoe-b, fatp4, lpl and fabp2) were reduced in zebrafish gut after exposure to metamifop, suggesting the lipid transportation were decreased. The transcripts of genes associated with inflammation (il-17c, tnf-α and nf-kb) were significantly increased in 0.40 mg/L metamifop treatment group, which were 1.90-, 1.53- and 2.77-fold of the control group, respectively, confirming that metamifop induced inflammatory response in zebrafish gut. Moreover, reduction of mRNA levels of cldn-15 and elevation of lipopolysaccharides (LPS) content were observed in metamifop-treated groups, which suggested that metamifop exposure increased the intestinal permeability. Furthermore, metamifop exposure decreased the relative abundance of beneficial bacteria (Psychrobacter and Aeromonas) and elevated the abundance of pathogenic bacteria (Rhodobacter and Ralstonia) in zebrafish intestine. These results indicated that metamifop exposure at sublethal concentrations would impair zebrafish gut health, via reduction of lipids absorption, inflammatory response, elevation of permeability and microbiota disorder.

Di-(2-ethylhexyl) phthalate exposure links to inflammation and low bone mass in premenopausal and postmenopausal females: Evidence from ovariectomized mice and humans

OBJECTIVE

Phthalates induce inflammation and are ubiquitously used in daily life. We aim to study the impact of di-(2-ethylhexyl) phthalate (DEHP) exposure on inflammation and osteoporosis in premenopausal and postmenopausal females.

METHODS

Female 8-week-old C57BL/6JNarl mice received an ovariectomy (OVX) or a sham operation and were fed with DEHP or vehicle by oral gavage for 4 or 8 weeks. Their femurs were isolated for micro-computed tomography, and their serum was collected for inflammatory cytokine assays. Correlations between urinary phthalate metabolites and the lumbar spine bone mineral density (BMD) in premenopausal and postmenopausal volunteers were performed.

RESULTS

Among the OVX mice treated for 4 weeks, significant lower bone volume, bone volume/tissue volume, and trabecular number but significant higher trabecular bone pattern factor and structure model index were identified in the mice treated with DEHP than with vehicle. The OVX mice treated with DEHP for 4 weeks had significantly higher serum interleukin (IL)-1β, IL-10, IL-17A, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and Dickkopf-1 levels than those treated with vehicle. The sham mice treated with DEHP for 8 weeks showed an impaired femur trabecular microstructure and had significantly higher serum IL-1β, IL-6, IL-10, IL-17A, IFN-γ, and TNF-α than those treated with vehicle. DEHP metabolites were inversely correlated with the BMD of premenopausal women and the T-score of postmenopausal women.

CONCLUSION

DEHP treatment in OVX and sham mice results in osteoporosis and impairs the microstructure of the femur trabecula through inflammation. Phthalate exposure negatively affects the bone mass in both premenopausal and postmenopausal women. Thus, long-term avoidance is suggested.

Di-(2-ethylhexyl) phthalate exacerbated the toxicity of polystyrene nanoplastics through histological damage and intestinal microbiota dysbiosis in freshwater Micropterus salmoides

Organic pollutants such as di-(2-ethylhexyl) phthalate (DEHP) interact with nanoplastics (NPs) and change their bioavailability and toxicity to aquatic organisms. This study aims to assess the ecotoxicological impacts of NPs in the presence and absence of DEHP on juvenile largemouth bass (LMB) Micropterus salmoides. Therefore, LMB was fed with diets containing various concentrations (0, 2, 10, and 40 mg/g) of polystyrene nanoplastics (PSNPs) by the weight of diets. After a 21-day of PSNPs dietary exposure, LMB was treated with DEHP at 450 μg/L through waterborne exposure for three days. Our results showed that PSNPs were accumulated in the intestinal tissues, which significantly decreased the feeding and growth rates in LMB. The histopathological analysis showed the intestine and liver of LMB were subjected to various degrees of structural damage caused by PSNPs, and DEHP-PSNP co-exposure enhanced those histopathological damages in both tissues. Additionally, the co-exposure induced oxidative stress in terms of increased activities of glutathione S-transferase, catalase, and superoxide dismutase enzymes in the liver, intestine, spleen, and serum. Furthermore, the co-exposure significantly changed the intestinal microbial composition, i.e., the decrease in the abundance of probiotics (Bacteroidetes and Proteobacteria) and the increase in pathogenic bacteria (Firmicutes) posed a great threat to fish metabolism and health. Therefore, this study highlights that the presence of DEHP enhances the toxicity of NPs on LMB in freshwater and suggests the regulated use of plastic and its additives for improving the health status of aquaculture fish for food safety in humans.

Di-(2-ethyl hexyl) phthalate induced oxidative stress promotes microplastics mediated apoptosis and necroptosis in mice skeletal muscle by inhibiting PI3K/AKT/mTOR pathway

The plastic decomposition product microplastics (MPs) and the plastic additive Di (2-ethylhexyl) phthalate (DEHP) in the environment can damage various organs of the organism by inducing oxidative stress. The PI3K/AKT/mTOR signaling pathway participate in toxin-induced apoptosis and necroptosis. However, the effects of DEHP/MPs alone and combined exposure on skeletal muscle cell injury in mice and the role of PI3K/AKT/mTOR axis remain unclear. To investigate the effect of DEHP or/and MPs on skeletal muscle in mice and its possible toxicological mechanism, 60 mice were randomly divided into control group, DEHP group (DEHP 200 mg/kg dissolved in 50 mL corn oil mixed with 2.5 kg diet), MPs group (10 mg/L MPs in drinking water) and combined exposure group. In vitro, C2C12 cells were exposed to DEHP 600 μM/MPs 800 μM alone or in combination for 24 h. The results showed that DEHP/MPs exposure alone or in combination increased MDA content, decreased activities of CAT, T-AOC, SOD and GSH-Px, increased mRNA and protein expressions of Caspase-3, BAX, RIPK1, RIPK3 and MLKL, and decreased BCL-2 expression. The expression of PI3K/AKT/mTOR signaling pathway was significantly down-regulated. All the above results showed that the combined exposure group was more toxic, and similar experimental results were obtained by DEHP/MPs exposure test of C2C12 cells in vitro. It is suggested that DEHP/MPs can induce apoptosis and necroptosis by activating oxidative stress and down-regulating PI3K/AKT/mTOR pathway. This study provides new evidence for clarifying the possible mechanism of toxicity of DEHP and MPs to skeletal muscle of mice.

To Waste or Not to Waste: Questioning Potential Health Risks of Micro- and Nanoplastics with a Focus on Their Ingestion and Potential Carcinogenicity

Micro- and nanoplastics (MNPs) are recognized as emerging contaminants, especially in food, with unknown health significance. MNPs passing through the gastrointestinal tract have been brought in context with disruption of the gut microbiome. Several molecular mechanisms have been described to facilitate tissue uptake of MNPs, which then are involved in local inflammatory and immune responses. Furthermore, MNPs can act as potential transporters ("vectors") of contaminants and as chemosensitizers for toxic substances ("Trojan Horse effect"). In this review, we summarize current multidisciplinary knowledge of ingested MNPs and their potential adverse health effects. We discuss new insights into analytical and molecular modeling tools to help us better understand the local deposition and uptake of MNPs that might drive carcinogenic signaling. We present bioethical insights to basically re-consider the "culture of consumerism." Finally, we map out prominent research questions in accordance with the Sustainable Development Goals of the United Nations.