Imidacloprid disturbed the gut barrier function and interfered with bile acids metabolism in mice

Pollution characteristics, environmental issues, and green development of neonicotinoid insecticides in China: Insights from Imidacloprid

Imidacloprid (IMI), a leading neonicotinoid insecticide, is widely used in China. Nevertheless, owing to its high toxicity to pollinators, regulatory scrutiny of its usage has increased in recent years. Despite this, no relevant issues have been announced in China, and its usage continues to rise. In this study, we systematically reviewed the development history, pollution characteristics, and environmental problems associated with IMI in China, which is imperative to promote its green development. The results show that most IMI products (97.1%) in China are registered for agricultural use. Owing to its extensive use and strong migration ability in different environmental matrices, IMI has been broadly detected in multiple environmental media. The average detection rate (DR) of IMI in soils, ambient water, and sediments were 90.7%, 81.3% and 84.5%, respectively, and the corresponding concentrations were 54.6 ± 83.8 ng/g dry weight (dw), 32.8 ± 103 ng/L, and 1.7 ± 2.9 ng/g dw, respectively, indicating high IMI abundance in multiple environmental media in China. The spatiotemporal distribution of IMI was generally determined by its application modes, transport, and degradation rates. IMI is commonly overused in China, leading to the development of high IMI resistance in many pests, and a high DR of IMI in food, drinking water, and human bodies. To alleviate IMI pollution in China, the joint efforts of the government, farmers, and scientists are necessary, including but not limited to formulating laws and regulations, strengthening governmental supervision, improving farmers' knowledge of IMI use, and promoting technological innovation in IMI and application methods.

Fibrous foes: First report on insidious microplastic contamination in dietary fiber supplements

Regular consumption of health supplements to balance dietary intake has gained popularity worldwide. One such supplement that has gained popularity among consumers is dietary fibers. Microplastic (MPs) contamination in various food products is being reported worldwide. However, there is a paucity of understanding of the occurrence of MPs in dietary supplements. This study addresses this gap by investigating the degree of MPs contamination in dietary fiber supplements. Nine commonly consumed (powder and gummy-based) over-the-counter dietary fiber supplements in Australia were tested in this study. Microscopic examination revealed the presence of MPs fibers and fragments in all the tested products. Further categorization showed that MPs particles were of various colours, including black, blue, red, green, and white. The order of polymer abundance was Polyamide > Polydiallyl Phthalate > polyethylene polypropylene diene > Polyurethane = Polyethylene terephthalate > Polyethylene = Ethylene acrylic acid copolymer. Among the supplements, powder-based samples had higher MPs (at the adult dosage suggested by the manufacturer) than gummy-based product. The average predicted ingestion of microplastics from these supplements (all nine samples) was 5.89 ± 2.89 particles day-1. The dietary exposure for children and adults ranged from 0.1-0.48 and 0.18-4.08 particles day-1, respectively. Based on the microplastic contamination factor (MCF), among the nine samples tested, 69.81% exhibited a moderate level, while 20.76% showed a significant level of microplastic contamination. The polymer risk index (pRi) indicates products with very high and high-risk categories. The possible sources of MPs contamination in the products were studied. To our knowledge, this is the first study to record and quantify the presence of MPs in dietary fiber supplements, which is a direct source of MPs exposure to humans via., ingestion.

Synergistic risk in the gut and liver: Insights into the toxic mechanisms and molecular interactions of combined exposure to triazophos and fenvalerate in zebrafish

The simultaneous or sequential application of pesticides such as triazophos (TRI) and fenvalerate (FEN) in agriculture results in their residues co-existing in the environments. However, the impact of co-exposure to TRI and FEN on the gut-liver axis, along with the underlying mechanisms, remains unclear. Our results showed that exposure to FEN (96 h-LC50 value of 0.096 mg a.i. L-1) was more toxic to adult zebrafish compared to TRI (96 h-LC50 value of 6.75 mg a.i. L-1). Furthermore, the study aimed to reveal the toxic potencies of individual and combined exposure to TRI and FEN on the liver-gut axis in zebrafish (Danio rerio). Our results also indicated that pesticide exposure decreased tight junction molecule expression and increased intestinal inflammatory molecule expression in D. rerio, with co-exposure demonstrating enhanced toxicity. Co-exposure altered gut flora structure and species abundance. RNA-Seq sequencing revealed changes in liver gene expressions, particularly enrichment of P53 signaling. Molecular docking demonstrated FEN's stronger binding to P53 and Caspase3, correlating with its higher toxicity. Liver pathology confirmed exacerbated liver damage by individual and co-exposures, with co-exposure inducing more severe liver injury. qPCR results showed increased pro-apoptotic gene expression and decreased anti-apoptotic gene expression, with co-exposure exhibiting an interactive effect. Overall, this study identifies specific targets and pathways influenced by these pesticides, revealing toxicity mechanisms involving the gut-liver axis, which is crucial for environmental risk assessment of pesticide mixtures.

Epoxiconazole disturbed metabolic balance and gut microbiota homeostasis in juvenile zebrafish

Epoxiconazole (EPX) is a broad-spectrum fungicide extensively used in agricultural pest control. Emerging evidence suggests that EPX can adversely affect different endpoints in non-target organisms. Here, the toxicity of EPX was assessed using earlier developmental stage of zebrafish as a model to investigate its effects on metabolism and intestinal microbiota after 21 days of exposure. Our findings indicated that EPX exposure resulted in physiological alterations in juvenile zebrafish, including increase in triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), and glycose (Glu). Nile red staining demonstrated enhanced lipid accumulation in juvenile, accompanied by a marked upregulation in the expression of genes associated with TG synthesis. Moreover, EPX led to alterations in amino acids and carnitines levels in 21 dpf (days post fertilization) zebrafish. We also observed that EPX disrupted intestinal barrier function in juvenile zebrafish, manifested by decreasing mucus secretion and changing in genes related to tight junctions. Moreover, for a more comprehensive analysis of the intestinal microbiota in 21 dpf zebrafish, the intestine tissues were dissected under a microscope for 16S rRNA sequencing analysis. The results revealed that EPX altered the structure and abundance of intestinal microflora in zebrafish, including decreased alpha diversity indices and shifted in bacteria at phylum and genus levels. Notably, the correlation analysis demonstrated strong associations between alterations in various pathogenic bacterial genera and levels of amino acids and carnitines. Overall, these findings confirm that the fungicide EPX promotes metabolic disorders and alterations in the intestinal micro-environment in 21 dpf zebrafish, shedding light on the toxicologic effects of chemicals to aquatic organisms during the development stage.

Impact of imidacloprid exposure on gestational hyperglycemia: A multi-omics analysis

Imidacloprid (IMI), a commonly utilized neonicotinoid insecticide, has been identified to adversely impact glucose homeostasis. Pregnant women are believed to be more sensitive to toxins than non-pregnant women, and the impact of IMI exposure on gestational hyperglycemia remain unclear. To explore the impact, pregnant mice fed a high-fat diet were exposed to different doses (0.06, 0.6, 6 mg/kg bw/day) of IMI by gavage. Glucose homeostasis-related parameters were measured. The glucose homeostasis influenced by IMI treatment was explored through integrating gut microbiota, metabolomic and transcriptomic analysis. Results showed that IMI-H (6 mg/kg bw/day) exposure notably restricted gestational weight gain and perturbed glucose homeostasis characterized by reduced glucose tolerance and insulin sensitivity, alongside elevated levels of fasting blood glucose and insulin. Multi-omics analysis revealed that IMI-H exposure induced significant changes in the richness and composition of the gut microbiome. The metabolite profiles of serum samples and cecal contents, and transcriptome of liver and ileum were all affected by IMI-H treatment. The altered gut microbiota, metabolites and genes exhibited significant correlations with glucose homeostasis-related parameters. These differential metabolites and genes were implicated in various metabolic pathways including bile secretion, glucagon signaling pathway, lipid metabolism, fatty acid metabolism. Significant correlations were observed between the altered gut microbiota and caecum metabolome as well as liver transcriptome. For example, the abundance of Oscillibacter was strongly correlated with gut microflora-related metabolites (Icosenoic acid, Lysosulfatide, and fluticasone) and liver differential genes (Grin3b, Lifr, and Spta1). Together, IMI exposure resulted in significant changes in microbial composition, along with alterations in certain metabolites and genes associated with metabolic process, which may promote gestational hyperglycemia.

Non-acute exposure of neonicotinoids, health risk assessment, and evidence integration: a systematic review

Neonicotinoid pesticides are utilized against an extensive range of insects. A growing body of evidence supports that these neuro-active insecticides are classified as toxicants in invertebrates. However, there is limited published data regarding their toxicity in vertebrates and mammals. the current systematic review is focused on the up-to-date knowledge available for several neonicotinoid pesticides and their non-acute toxicity on rodents and human physiology. Oral lethal dose 50 (LD50) of seven neonicotinoids (i.e. imidacloprid, acetamiprid, clothianidin, dinotefuran, thiamethoxam, thiacloprid, and nitenpyram) was initially identified. Subsequently, a screening of the literature was conducted to collect information about non-acute exposure to these insecticides. 99 studies were included and assessed for their risk of bias and level of evidence according to the Office of Health and Translation (OHAT) framework. All the 99 included papers indicate evidence of reproductive toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, immunotoxicity, and oxidative stress induction with a high level of evidence in the health effect of rodents and a moderate level of evidence for human health. The most studied type of these insecticides among 99 papers was imidacloprid (55 papers), followed by acetamiprid (22 papers), clothianidin (21 papers), and thiacloprid (11 papers). While 10 of 99 papers assessed the relationship between clothianidin, thiamethoxam, dinotefuran, and nitenpyram, showing evidence of liver injury, dysfunctions of oxidative stress markers in the reproductive system, and intestinal toxicity. This systematic review provides a comprehensive overview of the potential risks caused by neonicotinoid insecticides to humans and rodents with salient health effects. However, further research is needed to better emphasize and understand the patho-physiological mechanisms of these insecticides, taking into account various factors that can influence their toxicity.

High-throughput screening of the effects of 90 xenobiotics on the simplified human gut microbiota model (SIHUMIx): a metaproteomic and metabolomic study

The human gut microbiota is a complex microbial community with critical functions for the host, including the transformation of various chemicals. While effects on microorganisms has been evaluated using single-species models, their functional effects within more complex microbial communities remain unclear. In this study, we investigated the response of a simplified human gut microbiota model (SIHUMIx) cultivated in an in vitro bioreactor system in combination with 96 deep-well plates after exposure to 90 different xenobiotics, comprising 54 plant protection products and 36 food additives and dyes, at environmentally relevant concentrations. We employed metaproteomics and metabolomics to evaluate changes in bacterial abundances, the production of Short Chain Fatty Acids (SCFAs), and the regulation of metabolic pathways. Our findings unveiled significant changes induced by 23 out of 54 plant protection products and 28 out of 36 food additives across all three categories assessed. Notable highlights include azoxystrobin, fluroxypyr, and ethoxyquin causing a substantial reduction (log2FC < -0.5) in the concentrations of the primary SCFAs: acetate, butyrate, and propionate. Several food additives had significant effects on the relative abundances of bacterial species; for example, acid orange 7 and saccharin led to a 75% decrease in Clostridium butyricum, with saccharin causing an additional 2.5-fold increase in E. coli compared to the control. Furthermore, both groups exhibited up- and down-regulation of various pathways, including those related to the metabolism of amino acids such as histidine, valine, leucine, and isoleucine, as well as bacterial secretion systems and energy pathways like starch, sucrose, butanoate, and pyruvate metabolism. This research introduces an efficient in vitro technique that enables high-throughput screening of the structure and function of a simplified and well-defined human gut microbiota model against 90 chemicals using metaproteomics and metabolomics. We believe this approach will be instrumental in characterizing chemical-microbiota interactions especially important for regulatory chemical risk assessments.

Environmentally Relevant Concentrations of Microplastic Exposure Cause Cholestasis and Bile Acid Metabolism Dysregulation through a Gut-Liver Loop in Mice

The massive production of plastics causes the ubiquitous existence of microplastics (MPs) in the biota, therefore, posing exposure risks and potential health concerns to human beings. However, the exact mechanisms of MPs-induced toxicities and abnormalities are largely unknown. In this study, we developed a mouse model of gavage polystyrene microplastics (PS MPs) for 30 days. We found that PS MPs can damage the intestinal barrier, accumulate in the liver tissue, and cause injury. The liver and intestine are both highly associated with bile acid (BA) metabolism. Indeed, we found that PS MPs dysregulate BA synthesis and efflux-related gene expression in the liver, causing cholestasis. Tandemly, PS MPs alter the ratio of primary to secondary BA in the feces by affecting the composition of the intestinal flora. At last, PS MPs alter mice's fecal BA profile, which affects normal BA metabolism. Taken together, the present study provides robust data on the mechanism of toxicity of MPs causing the disturbance of BA metabolism via a 4-step gut-liver loop.

Impacts of prothioconazole and prothioconazole-desthio on bile acid and glucolipid metabolism: Upregulation of CYP7A1 expression in HepG2 cells

As an efficient triazole fungicide, prothioconazole (PTC) is widely used for the prevention and control of plant fungal pathogens. It was reported that the residues of PTC and prothioconazole-desthio (PTC-d) have been detected in the environment and crops, and the effects of PTC-d may be higher than that of PTC. Currently, PTC and PTC-d have been proven to induce hepatic metabolic disorders. However, their toxic effects on cellular bile acid (BA) and glucolipid metabolism remain unknown. In this study, HepG2 cells were exposed to 1-500 μM of PTC or PTC-d. High concentrations of PTC and PTC-d were found to induce cytotoxicity; thus, subsequent experimental exposure was conducted at concentrations of 10-50 μM. The expression levels of CYP7A1 and TG synthesis-related genes and levels of TG and total BA were observed to increase in HepG2 cells. Molecular docking analysis revealed direct interactions between PTC or PTC-d and CYP7A1 protein. To further investigate the underlying mechanisms, PTC and PTC-d were treated to HepG2 cells in which CYP7A1 expression was knocked down using siCYP7A1. It was observed that PTC and PTC-d affected the BA metabolism process and regulated the glycolipid metabolism process by promoting the expression of CYP7A1. In summary, we comprehensively analyzed the effects and mechanisms of PTC and PTC-d on cellular metabolism in HepG2 cells, providing theoretical data for evaluating the safety and potential risks associated with these substances.

Uptake, transport and accumulation of micro- and nano-plastics in terrestrial plants and health risk associated with their transfer to food chain - A mini review

Waste plastics enter the environment (water, soil, and atmosphere) and degrade into micro- and nano-plastics (MNPs) through physical, chemical, or biological processes. MNPs are ubiquitous in the environment and inevitably interact with terrestrial plants. Terrestrial plants have become important potential sinks, and subsequently, the sources of MNPs. At present, many studies have reported the effects of MNPs on plant physiology, biochemistry, and their phototoxicity. However, the source, detection method, and the absorption process of MNPs in terrestrial plants have not been systematically studied. In order to better understand the continuous process of MNPs entering terrestrial plants, this review introduces the sources and analysis methods of MNPs in terrestrial plants. The uptake pathways of MNPs in terrestrial plants and their influencing factors were systematically summarized. Meanwhile, the transport pathways and the accumulation of MNPs in different plant organs (roots, stems, leaves, calyxes, and fruits) were explored. Finally, the transfer of MNPs through food chains to humans and their health risks were discussed. The aim of this work is to provide significant theoretical knowledge to understand the uptake, transport, and accumulation of MNPs in terrestrial plants and the potential health risks associated with their transfer to humans through food chain.

Changes in toxicity after mixing imidacloprid and cadmium: enhanced, diminished, or both? From a perspective of oxidative stress, lipid metabolism, and amino acid metabolism in mice

Imidacloprid (IMI) and cadmium (Cd) are pollutants of concern in the environment. Although investigations about their combined toxicity to organisms such as earthworms, aquatic worms, Daphnia magna, and zebrafish have been carried out, their combined toxicity to mammals remains unknow. In this study, twenty-four 8-week-old mice were arbitrarily separated into 4 groups: CK (control group), IMI (15 mg/kg bw/day, 1/10 LD50), Cd (15 mg/kg bw/day, 1/10 LD50), and IMI + Cd (15 mg/kg bw/day IMI + 15 mg/kg bw/d Cd) and the combined toxic effects of IMI and Cd were examined with biochemical (oxidative stress testing) and omics approaches (metabolomics and lipidomics). The results revealed changes in each treatment group in terms of oxidative stress, abnormalities in lipid metabolism, and disturbances in amino acid metabolism. Co-administration had antagonistic effects on MDA accumulation and lipid metabolism disorders while acting synergistically on changes in SOD and GSH-Px activities. It is worth noting that after analysis, the changes caused by mixed administration in vivo were closer to those caused by IMI administration alone. This study provides new insights into the combined toxicity of neonicotinoids and heavy metals, which is helpful for relevant environmental governance and further investigations about their impacts on human health and the environment.

Approach to an answer to "How dangerous microplastics are to the human body": A systematic review of the quantification of MPs and simultaneously exposed chemicals

This review aims to facilitate future research on microplastics (MPs) in the environment using systematic and analytical protocols, ultimately contributing to assessment of the risk to human health due to continuous daily exposure to MPs. Despite extensive studies on MP abundance in environment, identification, and treatment, their negative effects on human health remain unknown due to the lack of proof from clinical studies and limited technology on the MP identification. To assess the risk of MPs to human health, the first step is to estimate MP intake via ingestion, inhalation, and dermal contact under standardized exposure conditions in daily life. Furthermore, rather than focusing on the sole MPs, migrating chemicals from plastic products should be quantified and their health risk be assessed concurrently with MP release. The critical factors influencing MP release and simultaneously exposed chemicals (SECs) must be investigated using a standardized identification method. This review summarises release sources, factors, and possible routes of MPs from the environment to the human body, and the quantification methods used in risk assessment. We also discussed the issues encountered in MP release and SEC migration. Consequently, this review provides directions for future MP studies that can answer questions about MP toxicity to human health.

Essential oil from Artemisia argyi alleviated liver disease in zebrafish (Danio rerio) via the gut-liver axis

The popularity of intensive fish farming has led to the emergence of fish diseases characterized by hepatobiliary syndrome. Artemisia argyi (A. argyi) essential oils have anti-inflammatory and anti-oxidant effects. However, their alleviating effects and mechanism on liver disease in fish are still unclear. Thus, adult zebrafish were used to construct an animal model to observe histopathological damages, determine biochemical parameters and expression of inflammatory cytokines and mRNAs in the PPAR-γ/NF-κB pathway, and conduct 16 S sequencing of intestinal microbiota. The results found that after treatment with A. argyi essential oil, the histopathological damage caused by ethanol was relieved; the CAT, SOD, and GSH levels were remarkably elevated, while the MDA level was obviously lowered (P < 0.05); the expression levels of IL-10 and IFN-γ mRNAs were enhanced, but the levels of IL-1β, IL-6, PPAR-γ, NF-κB, and TNF-α mRNAs were reduced (P < 0.05) relative to the EtOH group. A. argyi essential oil remarkably attenuated the damage to intestinal tissue structure, and elevated the levels of Muc2, ZO-1, Claudin-1, and Occludin mRNA (P < 0.05). Sequencing of the gut flora showed that A. argyi essential oil significantly altered the composition of gut microbes compared with the EtOH group. In addition, KEGG and COG analyses also showed significant (P < 0.05) changes in acetate cycling metabolism in the EtOH group, catechol 2, 3-dioxygenase and nitroreductase were significantly increased (P < 0.001), and lipid metabolism and terpenoid synthesis were significantly elevated (P < 0.001) in A. argyi essential oil group. The results indicate that A. argyi essential oil could effectively relieve ethanol-caused histopathological damage of livers by modulating the composition of gut microbiota, thus inhibiting the level of IL-1β and mRNAs in the PPAR-γ/NF-κB pathway, increasing the IL-10 level, reducing the oxidative stress. This may offer a rationale for further research on the rationality of A. argyi as a substitute for feed antibiotics in aquaculture.

Co-exposure of polycarbonate microplastics aggravated the toxic effects of imidacloprid on the liver and gut microbiota in mice

The joint toxicity of microplastics (MPs) and pesticides may be different from MPs or pesticides individually, however, the information about the combined toxicity of MPs and pesticides is not well understood. Herein, we investigated the joint toxicity of polycarbonate (PC) MPs and imidacloprid (IMI) on mice. After orally exposure for 4 weeks, PC and/or IMI lowered the body weight gain of mice. Single exposure of IMI induced the tissue damage in liver by disturbing the redox homeostasis, and PC significantly aggravated the imbalance of redox homeostasis by facilitating the accumulation of IMI in liver. Additionally, compared to single exposure of PC or IMI, PC+IMI exposure caused more severe damage to the gut microstructure and microbial diversity. Several key metabolic pathways, especially the lipid metabolism, were significantly affected. Overall, these findings provide new insight into understanding the potential risk of co-exposure of microplastics and pesticides to animal and human health.

Pesticide exposure and the microbiota-gut-brain axis

The gut microbiota exist within a dynamic ecosystem shaped by various factors that includes exposure to xenobiotics such as pesticides. It is widely regarded that the gut microbiota plays an essential role in maintaining host health, including a major influence on the brain and behaviour. Given the widespread use of pesticides in modern agriculture practices, it is important to assess the long-term collateral effects these xenobiotic exposures have on gut microbiota composition and function. Indeed, exposure studies using animal models have shown that pesticides can induce negative impacts on the host gut microbiota, physiology and health. In tandem, there is a growing body of literature showing that the effects of pesticide exposure can be extended to the manifestation of behavioural impairments in the host. With the increasing appreciation of the microbiota-gut-brain axis, in this review we assess whether pesticide-induced changes in gut microbiota composition profiles and functions could be driving these behavioural alterations. Currently, the diversity of pesticide type, exposure dose and variation in experimental designs hinders direct comparisons of studies presented. Although many insights presented, the mechanistic connection between the gut microbiota and behavioural changes remains insufficiently explored. Future experiments should therefore focus on causal mechanisms to examine the gut microbiota as the mediator of the behavioural impairments observed in the host following pesticide exposure.

Characterization of childhood exposure to environmental contaminants using stool in a semi-urban middle-class cohort from eastern Canada

Children are exposed to various environmental organic and inorganic contaminants with effects on health outcomes still largely unknown. Many matrices (e.g., blood, urine, nail, hair) have been used to characterize exposure to organic and inorganic contaminants. The sampling of feces presents several advantages; it is non-invasive and provides a direct evaluation of the gut microbiome exposure to contaminants. The gut microbiome is a key factor in neurological development through the brain-gut axis. Its composition and disturbances can affect the neurodevelopment of children. Characterization of children exposure to contaminants is often performed on vulnerable populations (e.g., from developing countries, low-income neighborhoods, and large urban centers). Data on the exposure of children from middle-class, semi-urban, and mid-size populations to contaminants is scarce despite representing a significant fraction of the population in North America. In this study, 73 organics compounds from different chemical classes and 22 elements were analyzed in 6 years old (n = 84) and 10 years old (n = 119) children's feces from a middle-class, semi-urban, mid-size population cohort from Eastern Canada. Results show that 67 out of 73 targeted organics compounds and all elements were at least detected in one child's feces. Only caffeine (97% & 80%) and acetaminophen (28% & 48%) were detected in more than 25% of the children's feces, whereas all elements besides titanium were detected in more than 50% of the children.

A new strategy to alleviate the obesity induced by endocrine disruptors-A unique lysine metabolic pathway of nanoselenium Siraitia grosvenorii to repair gut microbiota and resist obesity

Obesity caused by endocrine disruptors (EDCs) has become a hot topic threatening human health. Recently, Nanoselenium Siraitia grosvenorii (NSG) has been shown to have potential health-modulating uses. Based on the results of 16S rRNA sequencing and metabolomics analysis, NSG has the unique function of improving gut microbiota and inhibiting obesity. Specifically, NSG can enhance gut microbiota diversity and change their composition. A significant positive correlation exists between the liver change in lysine and the high-importance dominant species ([Ruminococcus]_gnavus, Alistipes_finegoldii, etc.). NSG metabolites analysis showed that the lysine level increased by 44.45% and showed a significantly negatively correlated with (TG, TC, Leptin, etc.). Significantly, NSG reduces the degradation of lysine metabolism in the liver and inhibits fatty acid β-oxidation. In addition, NSG decreased Acetyl-CoA levels by 24% and regulated the downregulation of TCA genes (CS, Ogdh, Fh1, and Mdh2) and the upregulation of ketone body production genes (BDH1). NSG may have a positive effect on obesity by reducing the participation of Acetyl-CoA in the TCA cycle pathway and enhancing the ketogenic conversion of Acetyl-CoA. In conclusion, the results of this study may provide a new dietary intervention strategy for preventing endocrine disruptor-induced obesity.

First evidence of neonicotinoid insecticides in human bile and associated hepatotoxicity risk

Neonicotinoids (NEOs) are widely applied in agricultural lands and are widespread in different environments, accelerating threats to ecosystems and human health. A number of in vitro/in vivo studies have reported adverse effects of NEOs on mammalian health, but the link between NEO exposure and toxic effects on human liver remains unclear. We randomly recruited 201 participants and quantified eight commercialized NEOs in bile. High frequency and concentration of detection indicate low degradation of human liver on NEOs. The main NEOs are nitenpyram and dinotefuran, which contribute to about 86% of the total residual levels of eight NEOs, due to the highest solubility in bile and are not degraded easily in liver. In contrast, imidacloprid and thiacloprid are major compounds in human blood, according to previous studies, suggesting that individual NEOs behave differently in blood and bile distribution. There was no statistical difference in NEO residues between cancer and non-cancer participants and among the different participant demographics (e.g., age, gender, and body mass index). The serum hematological parameters -bile acid, total bilirubin, cholesterol and alkaline phosphatase -were positively correlated with individual NEO concentrations, suggesting that NEO exposure affects liver metabolism and even enterohepatic circulation. The study first examined the NEO residues in human bile and provided new insights into their bioavailability and hepatoxicity risk.

Microplastics in human food chains: Food becoming a threat to health safety

While versatile application of plastics has generated huge benefits in our life, the 'plastic end-of-life' comes with downsides of emerging concern is plastic particles within all parts of environments. Plastics are highly resistant to degradation and sustain in the environment for a prolonged period resulting in easy access of microplastics into human food chain. Microplastic exposure to humans is caused by foods of both animal and plant origin, food additives, drinks, and plastic food packaging. Living organisms can accumulate microplastics in cells and tissues which results in threats of chronic biological effects and potential health hazards for humans including body gastrointestinal disorders, immunity, respiratory problem, cancer, infertility, and alteration in chromosomes. Because of the threat of microplastics on human health, it is essential to ensure food safety as well as control plastic use with strict regulation of proper management. This study aims to enlighten future research into the core component of microplastics, their exposure to human food, prevention to human food chain, and biological reactions in human body. Finally, it is recommended to consider the presence of microplastics in different foods, as most of the existing research mainly focused on sea foods. And it is important to study the mechanism of toxicity with pathways in the human body based on the different types, shapes, and sizes of plastic particles.

Melatonin alleviates lead-induced fatty liver in the common carps (Cyprinus carpio) via gut-liver axis

As a widespread aquatic environmental contaminant, Lead (Pb) can provoke hepatic injury in various animals. Melatonin (MT) plays a crucial role in the regulation of inflammatory response. Accumulating evidence elucidates exogenous toxins can elicit hepatic lipid metabolic disorders by influencing the gut microbiome. Nevertheless, the effects of Pb on gut microbiota and hepatic lipid metabolism of the common carps, and whether MT can prevent and cure Pb-induced toxicity via regulating microbiome remains unknown. Here, metagenomic and transcriptomic analysis were subsequently implemented to identify the Pb exposure-triggered prominent alternation of gut-liver signal. In the present study the severe intestinal injury and fatty liver formation caused by Pb in common carp were preliminarily determined. Metagenomic analysis confirmed that the gut microbiome dominant phyla, family and genus of the common carps were Fusobacteria, Fusobacteriaceae and Cetobacterium. Meanwhile, lipopolysaccharide (LPS) biosynthesis pathway was regarded as one of the main responsible for Pb exposure. Subsequently, LPS was demonstrated as the Pb-triggered microbial-derived signal of the common carps by ELISA analysis, and involves in the hepatic metabolic disorders via deteriorating the intestinal barrier. Additionally, it confirmed that hepatocytes ferroptosis associated with Pb-evoked fatty liver of the common carps, and the aggravation of lysosomal dyshomeostasis as well as inhibition of AMPK phosphorylation were referred to lipid metabolic disorders. The results of the present study demonstrated microbial-derived signal induced by aquatic Pb contaminant cause fatty liver formation in the common carps, and the protective effects of MT on Pb toxicity were performed by receding LPS over-synthesis, restraining microbiota-sourced LPS transport, along with attenuation of hepatocytes ferroptosis.

Neonicotinoid Insecticides and Their Metabolites Can Pass through the Human Placenta Unimpeded

Studies on neonicotinoid (NEO) exposure in pregnant women and fetuses are scarce, and transplacental transfer of these insecticides is unknown. In this study, parent NEOs (p-NEOs) and their metabolites (m-NEOs) were determined in 95 paired maternal (MS) and cord serum (CS) samples collected in southern China. Imidacloprid was the predominant p-NEO in both CS and MS samples, found at median concentrations of 1.84 and 0.79 ng/mL, respectively, whereas N-desmethyl-acetamiprid was the most abundant m-NEO in CS (median: 0.083 ng/mL) and MS (0.13 ng/mL). The median transplacental transfer efficiencies (TTEs) of p-NEOs and m-NEOs were high, ranging from 0.81 (thiamethoxam, THM) to 1.61 (olefin-imidacloprid, of-IMI), indicating efficient placental transfer of these insecticides. Moreover, transplacental transport of NEOs appears to be passive and structure-dependent: cyanoamidine NEOs such as acetamiprid and thiacloprid had higher TTE values than the nitroguanidine NEOs, namely, clothianidin and THM. Multilinear regression analysis revealed that the concentrations of several NEOs in MS were associated significantly with hematological parameters related to hepatotoxicity and renal toxicity. To our knowledge, this is the first analysis of the occurrence and distribution of NEOs in paired maternal-fetal serum samples.

Impact of a hexafluoropropylene oxide trimer acid (HFPO-TA) exposure on impairing the gut microbiota in mice

Hexafluoropropylene oxide trimer acid (HFPO-TA) has been used as an alternative of perfluorooctanoic acid (PFOA) in the fluoropolymer industry for several years. HFPO-TA is reported to have high capability of bioaccumulation, widespread environmental distribution, and multiple toxicities. However, its potential toxicity on the intestines and gut microbiota remains unknown. In the present study, male mice were orally exposed to 200 μg/L HFPO-TA for 6 weeks, and after total genomic DNA extraction, 16S rRNA amplicon pyrosequencing was performed. Our results demonstrated that HFPO-TA exposure resulted in the imbalance of cecal microbiota and alterations of cecal microbiota diversity. At the phylum level, the relative abundances of Proteobacteria, Deferribacteres, and Tenericutes increased in mice after exposure to HFPO-TA, while the relative abundances of Verrucomicrobia, Cyanobacteria, and TM7 decreased. At the genus level, the relative abundances of Ver Akkermansia, Pre Prevotella, Lac Coprococcus, Por_Parabacteroides, and Lac Dorea decreased in HFPO-TA exposed mice. Meanwhile, the increased relative abundances of Def_Mucispirillum, Des_Desulfovibrio and Odo Odoribacter were observed in HFPO-TA exposed mice. Additionally, KEGG metabolic pathway analysis revealed that HFPO-TA exposure changed the unsaturated fatty acid synthesis, fatty acid metabolism, glyoxylic acid and dicarboxylic acid metabolism, galactose metabolism pathway and other metabolic pathways. Collectively, all these findings indicate the potential gut toxicity of HFPO-TA and is perceived as a risk of health on gut microbiota. Future investigations should be warranted.

A rapid evidence assessment of the potential risk to the environment presented by active ingredients in the UK's most commonly sold companion animal parasiticides

A number of parasiticides are commercially available as companion animal treatments to protect against parasite infestation and are sold in large volumes. These treatments are not intended to enter the wider environment but may be washed off or excreted by treated animals and have ecotoxic impacts. A systematic literature review was conducted to identify the existing evidence for the toxicity of the six most used parasiticides in the UK: imidacloprid, fipronil, fluralaner, afoxolaner, selamectin, and flumethrin. A total of 17,207 published articles were screened, with 690 included in the final evidence synthesis. All parasiticides displayed higher toxicity towards invertebrates than vertebrates, enabling their use as companion animal treatments. Extensive evidence exists of ecotoxicity for imidacloprid and fipronil, but this focuses on exposure via agricultural use and is not representative of environmental exposure that results from use in companion animal treatments, especially in urban greenspace. Little to no evidence exists for the ecotoxicity of the remaining parasiticides. Despite heavy usage, there is currently insufficient evidence to understand the environmental risk posed by these veterinary treatments and further studies are urgently needed to quantify the levels and characterise the routes of environmental exposure, as well as identifying any resulting environmental harm.

RETRACTED: Combined Effects of Potassium Perchlorate and a Neonicotinoid on Zebrafish Larvae (Danio rerio)

Imidacloprid (IMI) is part of the neonicotinoids family, insecticides widely used by humans and also found in wastewater. This class of compounds, if present in the environment, can cause toxicity to different species such as bees and gammarids, although little is known about vertebrates such as fish. In addition, several substances have been reported in the environment that can cause damage to aquatic species, such as potassium perchlorate (KClO4), if exposed to high concentrations or for long periods. Often, the co-presence of different contaminants can cause a synergistic action in terms of toxicity to fish. In the present study, we first analyzed different concentrations of IMI (75, 100 and 150 mg/L) and KClO4 (1, 1.5 and 5 mM) to highlight the morphological effects at 96 hpf and, subsequently, chose two nontoxic concentrations to evaluate their co-exposure and the pathway involved in their co-toxicity. Morphological alteration, mucus production, messenger RNA (mRNA) expression related to intestinal function and oxidative stress were measured. These results suggest that co-exposure to IMI and KClO4 could affect zebrafish embryo development by increasing gut toxicity and the alteration of antioxidative defense mechanisms.

Synergistic effect of ZnO NPs and imidacloprid on liver injury in male ICR mice: Increase the bioavailability of IMI by targeting the gut microbiota

Although many toxicological studies on pesticides and nanoparticles have been conducted, it is not clear whether nanoparticles will increase the toxicity of pesticides. In this study, we chose imidacloprid (IMI) as a representative pesticide, and explored the influence of ZnO NPs on the toxic effect of IMI. In addition, we studied the bioaccumulation of IMI in mice. Using biochemical index analysis, liver histopathological analysis, non-targeted metabolomics, and LC/MS analysis, we found that ZnO NPs increased the toxicity of IMI, which may be related to the increase in IMI bioaccumulation in mice. In addition, we used intestinal histopathological analysis, RT-qPCR, and 16sRNA sequencing to find that the disturbance of the gut microbiota and the impaired intestinal barrier caused by ZnO NPs may be the reason for the increase in IMI bioaccumulation. In summary, our results indicate that ZnO NPs disrupted the intestinal barrier and enhanced the bioaccumulation of IMI, and therefore increased the toxicity of IMI in mice. Our research has deepened the toxicological insights between nanomaterials and pesticides.

Gut Microbiota: A Key Regulator in the Effects of Environmental Hazards on Modulates Insulin Resistance

Insulin resistance is a hallmark of Alzheimer’s disease (AD), type II diabetes (T2D), and Parkinson’s disease (PD). Emerging evidence indicates that these disorders are typically characterized by alterations in the gut microbiota composition, diversity, and their metabolites. Currently, it is understood that environmental hazards including ionizing radiation, toxic heavy metals, pesticides, particle matter, and polycyclic aromatic hydrocarbons are capable of interacting with gut microbiota and have a non-beneficial health effect. Based on the current study, we propose the hypothesis of “gut microenvironment baseline drift”. According to this “baseline drift” theory, gut microbiota is a temporarily combined cluster of species sharing the same environmental stresses for a short period, which would change quickly under the influence of different environmental factors. This indicates that the microbial species in the gut do not have a long-term relationship; any split, division, or recombination may occur in different environments. Nonetheless, the “baseline drift” theory considers the critical role of the response of the whole gut microbiome. Undoubtedly, this hypothesis implies that the gut microbiota response is not merely a “cross junction” switch; in contrast, the human health or disease is a result of a rich palette of gut-microbiota-driven multiple-pathway responses. In summary, environmental factors, including hazardous and normal factors, are critical to the biological impact of the gut microbiota responses and the dual effect of the gut microbiota on the regulation of biological functions. Novel appreciation of the role of gut microbiota and environmental hazards in the insulin resistance would shed new light on insulin resistance and also promote the development of new research direction and new overcoming strategies for patients.

Association between new onset type 1 diabetes and real-world antibiotics and neonicotinoids' exposure-related gut microbiota perturbation

BACKGROUND

The real-world exposure levels of non-therapeutic antibiotics and neonicotinoids in type 1 diabetes (T1D) children and their associations as environmental triggers through gut microbiota shifts remained unknown. We thus investigated the antibiotics and neonicotinoids' exposure levels and their associations with gut microbiota in pediatric T1D.

METHODS

Fifty-one newly onset T1D children along with 67 age-matched healthy controls were recruited. Urine concentrations of 28 antibiotics and 12 neonicotinoids were measured by mass spectrometry. Children were grouped according to the kinds of antibiotics' and neonicotinoids' exposures, respectively. The 16S rRNA of fecal gut microbiota was sequenced, and the correlation with urine antibiotics and neonicotinoids' concentrations was analyzed.

RESULTS

The overall detection rates of antibiotics were 72.5% and 61.2% among T1D and healthy children, whereas the neonicotinoids detection rates were 70.6% and 52.2% (P = 0.044). Children exposed to one kind of antibiotic or two or more kinds of neonicotinoids had higher risk of T1D, with the odd ratios of 2.579 and 3.911. Furthermore, co-exposure to antibiotics and neonicotinoids was associated with T1D, with the odd ratio of 4.924. Antibiotics or neonicotinoids exposure did not affect overall richness and diversity of gut microbiota. However, children who were exposed to neither antibiotics nor neonicotinoids had higher abundance of Lachnospiraceae than children who were exposed to antibiotics and neonicotinoids alone or together.

CONCLUSION

High antibiotics and neonicotinoids exposures were found in T1D children, and they were associated with changes in gut microbiota featured with lower abundance of butyrate-producing genera, which might increase the risk of T1D.

Parental exposure 3-methylcholanthrene disturbed the enterohepatic circulation in F1 generation of mice

3-methylcholanthrene (3 MC) is an environmental compound belonging to the PAHs and is reportedly thought to be a risk factor for the prevalence of hepatic function disorder. Here, a dose of 0.5 mg/kg of 3 MC was given to 4-week-old male and female mice (F0) in their diet for 6 weeks. After exposure, then the mice were mated between different groups. The first filial (F1) generation offspring of exposed or unexposed parental mice were sacrificed at the age of 5 weeks (F1-5 W), and the potential effects on the F0 and F1 offspring were evaluated. The results showed that the total bile acids (TBAs) in the serum and feces in F0 females and female F1-5 W individuals born from female mice exposed to 3 MC decreased, while the TBAs in the liver increased. The transcriptional levels of major genes participating in synthesis, regulation, transportation and apical uptake was also altered correspondingly. In addition, the transcription of some genes related to inflammation was enhanced in these mice. Further investigation revealed that in addition to distinct changes in the mucus secretion, tight junction proteins and ion transport were induced, and antimicrobial peptides were also disrupted in the intestine of F0 mice and F1-5 W female offspring of maternal mice exposed to 3 MC. Our results suggested that exposure to 3 MC, but not male exposure, had the potential to interfere with BAs metabolism, affecting gut barrier function. Females were more seriously affected than males.

Maternal exposure to sodium ρ-perfluorous nonenoxybenzene sulfonate during pregnancy and lactation disrupts intestinal barrier and may cause obstacles to the nutrient transport and metabolism in F0 and F1 generations of mice

Sodium ρ-perfluorous nonenoxybenzene sulfonate (OBS), a novel kind of perfluoroalkyl and polyfluoroalkyl compound, has been widely detected in the environment. The toxicity of OBS to living organisms has become a public concern. A growing body of research showed that maternal exposure to environmental pollutants caused intestinal and metabolic diseases that could be conserved across offspring. Here, female C57BL/6 mice were treated OBS at dietary levels of 0.0 mg/L (CON), 0.5 mg/L (OBS-L) and 5.0 mg/L (OBS-H) during the gestation and lactation periods. The results demonstrated that OBS treatment not only induced significant changes in the mucus secretion and ionic transport, but also disrupted the expression of antimicrobial peptides (AMPs) in the intestine of F0 and F1 generations. Additionally, OBS exposure altered bile acids metabolism and affected the transcriptional levels of critical genes involved in bile acids synthesis, signaling transfer, transportation and apical uptake. Together, all these results indicated that OBS exposure was perceived as a major stress by the intestinal epithelium that strongly affected the intestinal barrier function (including mucus, CFTR, AMPs, inflammation), and ultimately led to imbalance in the metabolism of bile acids (BAs). Moreover, we found that maternal OBS exposure had a more obvious toxicity effect on the male offspring in this experiment. Taken together, maternal OBS exposure during pregnancy and lactation had the intestinal and metabolism toxic effects on the dams and offspring, indicating that effects of maternal exposure on the toxicity of offspring could not be ignored.

Identification of pesticides in water samples by solid-phase extraction and liquid chromatography-electrospray ionization mass spectrometry

The Contaminants of Emerging Concern (CECs), including pesticides, have been a trending topic and Brazil is the country with the highest usage of pesticides worldwide. This study aimed to measure the presence of pesticide residues in the water from different sources in the city of Porto Alegre. We analyzed 55 samples from drinking water treatment plants, public water sites, and sewage treatment plants from winter 2018 to summer 2020 by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry. Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility) and 15 of them were detected in different water samples, including seven insecticides, five antifungals, and three herbicides, with a wide range of toxicity levels and noticeable seasonal differences. For the worst-case scenario evaluation, 20 out of 22 (90.9%) samples exceeded the Risk Quotient of 1. The sum of pesticide concentrations exceeded 100 ng L^-1 in 66.7% of samples in February 19 and in 75% of samples in February 20 and the total pesticide concentration has reached the worrisome mark of 1615 and 954.96 ng L^-1 respectively. Therefore, our results make evident the need to promote public policies to achieve better water quality monitoring. PRACTITIONER POINTS: Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility). A total of 55 different water samples were analyzed, and 15 pesticides were detected and five quantified. For the worst-case scenario evaluation, 20 out of 21 samples exceeded the Risk Quotient of 1 on Feb/20. The pesticide concentrations sum exceeded 100 ng L^-1 in 66.7% of samples on February 19 and in 75% of samples on February 20. It is mandatory to improve water monitoring to guide the development of public policies concerning its quality.

Imidacloprid increases intestinal permeability by disrupting tight junctions

The neonicotinoid pesticide, imidacloprid (IMI), is frequently detected in the environment and in foods. It is absorbed and metabolized by the intestine; however, its effects on intestinal barrier integrity are not well studied. We investigated whether IMI disrupts the permeability of the intestinal epithelial barrier via in vivo tests on male Wistar rats, in vitro assays using the human intestinal epithelial cell line, Caco-2, and in silico analyses. A repeated oral dose 90-day toxicity study was performed (0.06 mg/kg body weight/day). IMI exposure significantly increased intestinal permeability, which led to significantly elevated serum levels of endotoxin and inflammatory biomarkers (tumor necrosis factor-alpha and interleukin-1 beta) without any variation in body weight. Decreased transepithelial electrical resistance with increased permeability was also observed in 100 nM and 100 μM IMI-treated Caco-2 cell monolayers. Amounts of tight junction proteins in IMI-treated colon tissues and between IMI-treated Caco-2 cells were significantly lower than those of controls. Increased levels of myosin light chain phosphorylation, myosin light chain kinase (MLCK), and p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB p65) phosphorylation were found in IMI-exposed cells compared with control cells. Furthermore, the barrier loss caused by IMI was rescued by the MLCK inhibitor, ML-7, and cycloheximide. Pregnane X receptor (PXR, NR1I2) was inhibited by low-dose IMI treatment. In silico analysis indicated potent binding sites between PXR and IMI. Together, these data illustrate that IMI induces intestinal epithelial barrier disruption and produces an inflammatory response, involving the down-regulation of tight junctions and disturbance of the PXR-NF-κB p65-MLCK signaling pathway. The intestinal barrier disruption caused by IMI deserves attention in assessing the safety of this neonicotinoid pesticide.

Combined hepatotoxicity of imidacloprid and microplastics in adult zebrafish: Endpoints at gene transcription

Microplastics (MPs) and pesticides are two kinds of ubiquitous pollutants that can pose a health risk to aquatic organisms. However, researches about the combined effects of MPs and pesticides are very limited. A simple combined exposure model was established in this study, adult zebrafish were exposed to 100 μg/L imidacloprid (IMI), 20 μg/L polystyrene microplastics (PS), and a combination of PS and IMI (PS + IMI) for 21 days. The results demonstrated that exposure to PS and IMI inhibited the growth of zebrafish and altered the levels of glycolipid metabolism and oxidative stress-related biochemical parameters. While gene expression analysis revealed that, compared with PS or IMI treatment group, combined exposure caused a greater change in gene expression levels involving the process of glycolipid metabolism (Gk, Hk1, Aco, PPar-α, Cpt1, Acc, Fas, PPar-γ, Apo) and inflammatory response (IL-1β, IL-6, IL-8, TNF-α, IL-10). The results demonstrated that even combined exposure of low concentrations of PS and IMI could cause more severe hepatotoxicity in zebrafish, especially in terms of gene transcription. And more combined toxicity studies are essential for MPs and pesticides risk assessment.

Comparison of the toxicity of pure compounds and commercial formulations of imidacloprid and acetamiprid on HT-29 cells: Single and mixture exposure

Neonicotinoids, which are widely used worldwide, including in Turkey, are an insecticide group that are synthetic derivatives of nicotine. Recently, they have attracted attention due to their toxic effects on non-target organisms, especially bees. Numerous studies have shown that neonicotinoids have been found in detectable levels in the environment and cause various undesirable effects on living organisms, including humans and other mammals. In this study, the possible toxic effects of imidacloprid and acetamiprid, commonly used neonicotinoids, are investigated by their pure forms and commercial formulations on HT-29 cells with individual and combined exposures. According to our results, imidacloprid and acetamiprid induced cytotoxicity by caspase-mediated apoptosis, mitochondrial membrane depolarization, DNA damage, and oxidative stress under these experimental conditions. It is worth mentioning low doses of DNA damage, mixture exposure causes toxic effects at lower concentrations than individual exposure, and formulation groups are at the forefront of toxicity formation, though this varies depending on the parameters.

Imidacloprid induces locomotion impairment of the freshwater crayfish, Procambarus clarkii via neurotoxicity and oxidative stress in digestive system

Imidacloprid (IMI) is used in integrated farming like the rice-crayfish co-culture system to prevent water weevil. However, the toxic effect of IMI on the freshwater crayfish Procambarus clarkii is unknown. In the current study, the effects of IMI on the locomotion, antioxidative status, digestion and intestinal microbiota of P. clarkii were investigated. The results showed that IMI caused locomotion impairment with reduced crawl velocity, and attenuated their dark preference, aggressiveness and reversal ability. Inhibited AChE in muscle and hepatopancreas indicates the neurotoxicity of IMI which may directly lead their locomotion dysfunction. The increase of antioxidative enzymes activity and MDA level were found after 25 μg/L and 250 μg/L exposure. Significant up-regulation of several antioxidative and immune-related genes, including CZ-SOD, CAT, GPx, GST, AFL, proPO, HSP27 and HSP70 confirmed that oxidative stress was induced in all treatments when exposed to IMI. In addition, there was significant increase of LDH, indicating the different energy allocation during the exposure. Meanwhile, results from DNA damage analysis showed elevated OTM value and 8-OHdG level in hepatopancretic cells. On the other hand, decreases of alpha-amylase, lipase and increase of trypsin in hepatopancreas was observed at 25 and 250 μg/L. In addition, significant changes of composition of intestinal microbiota at both phylum and genus levels were observed according to the 16S rRNA sequencing results. Increase of pathogenic genera and decrease of beneficial bacterial communities revealed the disequilibrium of intestinal flora of crayfish. In summary, results in the present study suggest that IMI at environmentally realistic concentration could induce AChE inhibition and oxidative stress, conjointly leading the locomotion impairment in crayfish. IMI also affected the digestive functions by enzymes inhibition and gut microbiota dysbiosis.

Toxicology and Microbiota: How Do Pesticides Influence Gut Microbiota? A Review

In recent years, new targets have been included between the health outcomes induced by pesticide exposure. The gastrointestinal tract is a key physical and biological barrier and it represents a primary site of exposure to toxic agents. Recently, the intestinal microbiota has emerged as a notable factor regulating pesticides’ toxicity. However, the specific mechanisms related to this interaction are not well known. In this review, we discuss the influence of pesticide exposure on the gut microbiota, discussing the factors influencing gut microbial diversity, and we summarize the updated literature. In conclusion, more studies are needed to clarify the host–microbial relationship concerning pesticide exposure and to define new prevention interventions, such as the identification of biomarkers of mucosal barrier function.