The gut microbiota, a key to understanding the health implications of micro(nano)plastics and their biodegradation

Lactic acid bacteria reduce polystyrene micro- and nanoplastics-induced toxicity through their bio-binding capacity and gut environment repair ability

Microplastics and nanoplastics (MNPs) are emerging environmental contaminants that have received significant attention in recent years. Currently, there are more studies on the toxic effects of MNPs exposure on animals (especially aquatic organisms and mammals), but data on the reduction of toxic effects caused by MNPs exposure are still very limited. Lactic acid bacteria (LAB), recognized as safe food-grade microorganisms, possess the capability to bioconjugate harmful substances. In this experiment, we chose lactic acid bacteria (LAB) with different binding capacities to MNPs in vitro to intervene in MNPs-exposed mice to investigate the reducing effect on the toxicity caused by MNPs exposure. Our study showed that LAB with a high intercalation capacity with MNPs in vitro were more effective in alleviating the toxicity caused by MNPs exposure. Notably, Lactobacillus plantarum DT22, despite its low inter-adsorption with MNPs, played a pivotal role in upregulating the relative expression of tight junction proteins and modulating the intestinal microbiota. Thus, LAB strains' mitigation of MNPs toxicity extends beyond bio-binding; their capacity to repair the damaged gut environment is also crucial. LAB strains are proposed as a dietary intervention to reduce MNPs-induced toxicity.

Metagenomic and metatranscriptomic analyses reveal uncharted microbial constituents responsible for polyhydroxybutyrate biodegradation in coastal waters

Polyhydroxybutyrate (PHB) has attracted attention as a representative polymer for biodegradable plastics produced by microorganisms. Since information regarding the fate of PHB released into the environment is limited, it is necessary to identify them based on metagenomic information. We estimated the PHB biodegradability in coastal water samples collected from 15 near shore sites around Japan using oxygen consumption as an indicator in laboratory-scale incubation experiments and conducted 16S rRNA gene-based microbial community profiling. The PHB-biodegradation-rate was significantly positively correlated with the diversity indices of the microbial community in seawater prior to incubation, indicating that seawater with higher diversity is more advantageous for biodegradation. We identified 41 operational taxonomic units exhibiting a significant positive correlation between their abundance and PHB-degradation-rates; these included several microorganisms with hitherto unreported PHB-degrading ability. Next, we analyzed gene expression patterns over incubation time using seawater samples employing metagenomic and metatranscriptomic approaches. Fifty-seven putative extracellular PHB/PHA depolymerase genes were found in 38 metagenomic bins and their expression changed with increasing biodegradation rates, indicating that PHB released into the marine environment is subject to degradation by phylogenetically diverse PHB-depolymerase-producing bacteria. These findings should contribute to expanding the knowledge on degradation of biodegradable plastics by complex marine microbial ecosystems.

Microplastics - A Growing Concern as Carcinogens in Cancer Etiology: Emphasis on Biochemical and Molecular Mechanisms

In today's world, the widespread presence of microplastics is undeniable, with concentrations found in various environments, including up to 1000 particles per liter in seawater and up to 10 particles per cubic meter in the atmosphere. Originating from diverse sources, both intentional and unintentional, these minuscule fragments, measuring less than 5 mm, pose significant threats to environmental and human health. Recent research has uncovered a concerning link between microplastics and cancer, prompting urgent investigation. Studies demonstrate microplastics can infiltrate cells, disrupt biological processes, and potentially foster carcinogenic environments. From inducing DNA damage and oxidative stress to triggering inflammatory responses and dysregulating cellular pathways, microplastics exhibit a multifaceted capability in contributing to cancer development. Furthermore, microplastics act as carriers for a range of contaminants, compounding their impact on human health. Their accumulation within tissues and organs raises concerns for short and long-term health consequences, including chronic diseases, reproductive issues, and developmental abnormalities. This review explores the biochemical and molecular mechanisms underlying the interaction between microplastics and cellular systems, providing insights into routes of exposure and health effects, with a focus on lung, skin, and digestive system cancers. As we confront this pressing environmental and public health challenge, a deeper understanding of the microplastic-cancer relationship is crucial to safeguarding the well-being of present and future generations.

Gut microbiota, a key to understanding the knowledge gaps on micro-nanoplastics-related biological effects and biodegradation

Micro-nanoplastics (MNPs) pollution as a global environmental issue has received increasing interest in recent years. MNPs can enter and accumulate in the organisms including human beings mainly via ingestion and inhalation, and large amounts of foodborne MNPs have been frequently detected in human intestinal tracts and fecal samples. MNPs regulate the structure composition and metabolic functions of gut microbiota, which may cause the imbalance of intestinal ecosystems of the hosts and further mediate the occurrence and development of various diseases. In addition, a growing number of MNPs-degrading strains have been isolated from organismal feces. MNPs-degraders colonize the plastic surfaces and form the biofilms, and the long-chain polymers of MNPs can be biologically depolymerized into short chains. In general, MNPs are gradually degraded into small molecule substances (e.g., N2, CH4, H2O, and CO2) via a series of enzymatic catalyses, mainly including biodeterioration, fragmentation, assimilation, and mineralization. In this review, we outline the current progress of MNPs effects on gut microbiota and MNPs degradation by gut microbiota, which provide a certain theoretical basis for fully understanding the knowledge gaps on MNPs-related biological effect and biodegradation.

Microorganism Contribution to Mass-Reared Edible Insects: Opportunities and Challenges

The interest in edible insects' mass rearing has grown considerably in recent years, thereby highlighting the challenges of domesticating new animal species. Insects are being considered for use in the management of organic by-products from the agro-industry, synthetic by-products from the plastics industry including particular detoxification processes. The processes depend on the insect's digestive system which is based on two components: an enzymatic intrinsic cargo to the insect species and another extrinsic cargo provided by the microbial community colonizing-associated with the insect host. Advances have been made in the identification of the origin of the digestive functions observed in the midgut. It is now evident that the community of microorganisms can adapt, improve, and extend the insect's ability to digest and detoxify its food. Nevertheless, edible insect species such as Hermetia illucens and Tenebrio molitor are surprisingly autonomous, and no obligatory symbiosis with a microorganism has yet been uncovered for digestion. Conversely, the intestinal microbiota of a given species can take on different forms, which are largely influenced by the host's environment and diet. This flexibility offers the potential for the development of novel associations between insects and microorganisms, which could result in the creation of synergies that would optimize or expand value chains for agro-industrial by-products, as well as for contaminants.

Exposure to polyethylene microplastics exacerbate inflammatory bowel disease tightly associated with intestinal gut microflora

Polyethylene microplastics (PE MPs) have sparked widespread concern about their possible health implications because of their abundance, pervasiveness in the environment and in our daily life. Multiple investigations have shown that a high dosage of PE MPs may adversely impact gastrointestinal health. In tandem with the rising prevalence of Inflammatory bowel disease (IBD) in recent decades, global plastic manufacturing has risen to more than 300 million tons per year, resulting in a build-up of plastic by-products such as PE MPs in our surroundings. We have explored current advancements in the effect PE MPs on IBD in this review. Furthermore, we compared and summarized the detrimental roles of PE MPs in gut microbiota of different organisms viz., earthworms, super worm's larvae, yellow mealworms, brine shrimp, spring tails, tilapia, gilt-head bream, crucian carp, zebrafish, juvenile yellow perch, European sea bass, c57BL/6 mice and human. According to this review, PE MPs played a significant role in decreasing the diversity of gut microbiota of above-mentioned species which leads to the development of IBD and causes severe intestinal inflammation. Finally, we pinpoint significant scientific gaps, such as the movement of such hazardous PE MPs and the accompanying microbial ecosystems and propose prospective research directions.

Assessment of anthropogenic particles content in commercial beverages

Microplastic (MPs) pollution is a current global concern that is affecting all environmental compartments and food sources. In this work, anthropogenic particles occurrence (MPs and natural and synthetic cellulosic particles), have been determined in 73 beverages packed in different containers. Overall, 1521 anthropogenic particles were found, being the lowest occurrence in water samples (7.2 ± 10.1 items·L-1) while beer had the highest (95.5 ± 91.8 items·L-1). Colourless/white particles were the most detected followed by blue and red colours. The highest mean size was 783 ± 715 μm in soft drinks. Cellulosic, both natural and semisynthetic particles, were the composition mostly found but regarding plastic polymers, it was polyester. Phenoxy resin particles from the can coatings were also identified in all metal containers which indicates that leaching from the packaging may be happening. The total estimated daily intake were 0.077 and 0.159 items·kg-1 body weight (b.w.)·day-1 for children and adult population, respectively.

A Valuable Source of Promising Extremophiles in Microbial Plastic Degradation

Plastics have accumulated in open environments, such as oceans, rivers, and land, for centuries, but their effect has been of concern for only decades. Plastic pollution is a global challenge at the forefront of public awareness worldwide due to its negative effects on ecological systems, animals, human health, and national economies. Therefore, interest has increased regarding specific circular economies for the development of plastic production and the investigation of green technologies for plastic degradation after use on an appropriate timescale. Moreover, biodegradable plastics have been found to contain potential new hazards compared with conventional plastics due to the physicochemical properties of the polymers involved. Recently, plastic biodegradation was defined as microbial conversion using functional microorganisms and their enzymatic systems. This is a promising strategy for depolymerizing organic components into carbon dioxide, methane, water, new biomass, and other higher value bioproducts under both oxic and anoxic conditions. This study reviews microplastic pollution, the negative consequences of plastic use, and the current technologies used for plastic degradation and biodegradation mediated by microorganisms with their drawbacks; in particular, the important and questionable role of extremophilic multi-enzyme-producing bacteria in synergistic systems of plastic decomposition is discussed. This study emphasizes the key points for enhancing the plastic degradation process using extremophiles, such as cell hydrophobicity, amyloid protein, and other relevant factors. Bioprospecting for novel mechanisms with unknown information about the bioproducts produced during the plastic degradation process is also mentioned in this review with the significant goals of CO2 evolution and increasing H2/CH4 production in the future. Based on the potential factors that were analyzed, there may be new ideas for in vitro isolation techniques for unculturable/multiple-enzyme-producing bacteria and extremophiles from various polluted environments.

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.

The Plasticene era: Current uncertainties in estimates of the hazards posed by tiny plastic particles on soils and terrestrial invertebrates

Plastics are ubiquitous in our daily life. Large quantities of plastics leak in the environment where they weather and fragment into micro- and nanoparticles. This potentially releases additives, but rarely leads to a complete mineralization, thus constitutes an environmental hazard. Plastic pollution in agricultural soils currently represents a major challenge: quantitative data of nanoplastics in soils as well as their effects on biodiversity and ecosystem functions need more attention. Plastic accumulation interferes with soil functions, including water dynamics, aeration, microbial activities, and nutrient cycling processes, thus impairing agricultural crop yield. Plastic debris directly affects living organisms but also acts as contaminant vectors in the soils, increasing the effects and the threats on biodiversity. Finally, the effects of plastics on terrestrial invertebrates, representing major taxa in abundance and diversity in the soil compartment, need urgently more investigation from the infra-individual to the ecosystem scales.

Nanoplastics and Neurodegeneration in ALS

Plastic production, which exceeds one million tons per year, is of global concern. The constituent low-density polymers enable spread over large distances and micro/nano particles (MNPLs) induce organ toxicity via digestion, inhalation, and skin contact. Particles have been documented in all human tissues including breast milk. MNPLs, especially weathered particles, can breach the blood-brain barrier, inducing neurotoxicity. This has been documented in non-human species, and in human-induced pluripotent stem cell lines. Within the brain, MNPLs initiate an inflammatory response with pro-inflammatory cytokine production, oxidative stress with generation of reactive oxygen species, and mitochondrial dysfunction. Glutamate and GABA neurotransmitter dysfunction also ensues with alteration of excitatory/inhibitory balance in favor of reduced inhibition and resultant neuro-excitation. Inflammation and cortical hyperexcitability are key abnormalities involved in the pathogenic cascade of amyotrophic lateral sclerosis (ALS) and are intricately related to the mislocalization and aggregation of TDP-43, a hallmark of ALS. Water and many foods contain MNPLs and in humans, ingestion is the main form of exposure. Digestion of plastics within the gut can alter their properties, rendering them more toxic, and they cause gut microbiome dysbiosis and a dysfunctional gut-brain axis. This is recognized as a trigger and/or aggravating factor for ALS. ALS is associated with a long (years or decades) preclinical period and neonates and infants are exposed to MNPLs through breast milk, milk substitutes, and toys. This endangers a time of intense neurogenesis and establishment of neuronal circuitry, setting the stage for development of neurodegeneration in later life. MNPL neurotoxicity should be considered as a yet unrecognized risk factor for ALS and related diseases.

Plastics and the Sustainable Development Goals: From waste to wealth with microbial recycling and upcycling

Plastics pollution has become one of the greatest concerns of the 21st century. To date, around 10 billion tons of plastics have been produced almost exclusively from non-renewable sources, and of these, <10% have been recycled. The majority of discarded plastic waste (>70%) is accumulating in landfills or the environment, causing severe impacts to natural ecosystems and human health. Considering how plastics are present in every aspect of our daily lives, it is evident that a transition towards a Circular Economy of plastics is essential to achieve several of the Sustainable Development Goals. In this editorial, we highlight how microbial biotechnology can contribute to this shift, with a special focus on the biological recycling of conventional plastics and the upcycling of plastic-waste feedstocks into new value-added products. Although important hurdles will need to be overcome in this endeavour, recent success stories highlight how interdisciplinary approaches can bring us closer to a bio-based economy for the sustainable management of plastics.

The possible impacts of nano and microplastics on human health: lessons from experimental models across multiple organs

The widespread production and use of plastics have resulted in accumulation of plastic debris in the environment, gradually breaking down into smaller particles over time. Nano-plastics (NPs) and microplastics (MPs), defined as particles smaller than 100 nanometers and 5 millimeters, respectively, raise concerns due to their ability to enter the human body through various pathways including ingestion, inhalation, and skin contact. Various investigators demonstrated that these particles may produce physical and chemical damage to human cells, tissues, and organs, disrupting cellular processes, triggering inflammation and oxidative stress, and impacting hormone and neurotransmitter balance. In addition, micro- and nano-plastics (MNPLs) may carry toxic chemicals and pathogens, exacerbating adverse effects on human health. The magnitude and nature of these effects are not yet fully understood, requiring further research for a comprehensive risk assessment. Nevertheless, evidence available suggests that accumulation of these particles in the environment and potential human uptake are causes for concern. Urgent measures to reduce plastic pollution and limit human exposure to MNPLs are necessary to safeguard human health and the environment. In this review, current knowledge regarding the influence of MNPLs on human health is summarized, including toxicity mechanisms, exposure pathways, and health outcomes across multiple organs. The critical need for additional research is also emphasized to comprehensively assess potential risks posed by degradation of MNPLs on human health and inform strategies for addressing this emerging environmental health challenge. Finally, new research directions are proposed including evaluation of gene regulation associated with MNPLs exposure.

Impact of evolution on lifestyle in microbiome

This chapter analyses the interaction between microbiota and humans from an evolutionary point of view. Long-term interactions between gut microbiota and host have been generated as a result of dietary choices through coevolutionary processes, where mutuality of advantage is essential. Likewise, the characteristics of the intestinal environment have made it possible to describe different intrahost evolutionary mechanisms affecting microbiota. For its part, the intestinal microbiota has been of great importance in the evolution of mammals, allowing the diversification of dietary niches, phenotypic plasticity and the selection of host phenotypes. Although the origin of the human intestinal microbial community is still not known with certainty, mother-offspring transmission plays a key role, and it seems that transmissibility between individuals in adulthood also has important implications. Finally, it should be noted that certain aspects inherent to modern lifestyle, including refined diets, antibiotic intake, exposure to air pollutants, microplastics, and stress, could negatively affect the diversity and composition of our gut microbiota. This chapter aims to combine current knowledge to provide a comprehensive view of the interaction between microbiota and humans throughout evolution.

Toxic effects of nanoplastics and microcystin-LR coexposure on the liver-gut axis of Hypophthalmichthys molitrix

Plastic products and nutrients are widely used in aquaculture facilities, resulting in copresence of nanoplastics (NPs) released from plastics and microcystins (MCs) from toxic cyanobacteria. The potential effects of NPs-MCs coexposure on aquatic products require investigation. This study investigated the toxic effects of polystyrene (PS) NPs and MC-LR on the gut-liver axis of silver carp Hypophthalmichthys molitrix, a representative commercial fish, and explored the effects of the coexposure on intestinal microorganism structure and liver metabolic function using traditional toxicology and multi-omics association analysis. The results showed that the PS-NPs and MC-LR coexposure significantly shortened villi length, and the higher the concentration of PS-NPs, the more obvious the villi shortening. The coexposure of high concentrations of PS-NPs and MC-LR increased the hepatocyte space in fish, and caused obvious loss of gill filaments. The diversity and richness of the fish gut microbes significantly increased after the PS-NPs exposure, and this trend was amplified in the copresence of MC-LR. In the coexposure, MC-LR contributed more to the alteration of fish liver metabolism, which affected the enrichment pathway in glycerophospholipid metabolism and folic acid biosynthesis, and there was a correlation between the differential glycerophospholipid metabolites and affected bacteria. These results suggested that the toxic mechanism of PS-NPs and MC-LR coexposure may be pathological changes of the liver, gut, and gill tissues, intestinal microbiota disturbance, and glycerophospholipid metabolism imbalance. The findings not only improve the understanding of environmental risks of NPs combined with other pollutants, but also provide potential microbiota and glycerophospholipid biomarkers in silver carp.

Nanoplastic propels diet-induced NAFL to NASH via ER-mitochondrial tether-controlled redox switch

Nonalcoholic steatohepatitis (NASH) is multifactorial that lifestyle, genetic, and environmental factors contribute to its onset and progression, thereby posing a challenge for therapeutic intervention. Nanoplastic (NP) is emerged as a novel environmental metabolism disruptor but the etiopathogenesis remains largely unknown. In this study, C57BL/6 J mice were fed with normal chow diet (NCD) and high-fat diet (HFD) containing 70 nm polystyrene microspheres (NP). We found that dietary-derived NP adsorbed proteins and agglomerated during the in vivo transportation, enabling diet-induced hepatic steatosis to NASH. Mechanistically, NP promoted liver steatosis by upregulating Fatp2. Furthermore, NP stabilized the Ip3r1, and facilitated ER-mitochondria contacts (MAMs) assembly in the hepatocytes, resulting in mitochondrial Ca2+ overload and redox imbalance. The redox-sensitive Nrf2 was decreased in the liver of NP-exposed mice, which positively regulated miR26a via direct binding to its promoter region [-970 bp to -847 bp and -318 bp to -176 bp]. NP decreased miR26a simultaneously upregulated 10 genes involved in MAMs formation, lipid uptake, inflammation, and fibrosis. Moreover, miR26a inhibition elevated MAMs-tether Vdac1, which promoted the nucleus translocation of NF-κB P65 and Keap1 and functionally inactivated Nrf2, leading to a vicious cycle. Hepatocyte-specific overexpressing miR26a effectively restored ER-mitochondria miscommunication and ameliorated NASH phenotype in NP-exposed and Keap1-overexpressed mice on HFD. The hepatic MAM-tethers/Nrf2/miR26a feedback loop is an essential metabolic switch from simple steatosis to NASH and a promising therapeutic target for oxidative stress-associated liver damage and NASH.

Micro(nano)plastics in the Human Body: Sources, Occurrences, Fates, and Health Risks

The increasing global attention on micro(nano)plastics (MNPs) is a result of their ubiquity in the water, air, soil, and biosphere, exposing humans to MNPs on a daily basis and threatening human health. However, crucial data on MNPs in the human body, including the sources, occurrences, behaviors, and health risks, are limited, which greatly impedes any systematic assessment of their impact on the human body. To further understand the effects of MNPs on the human body, we must identify existing knowledge gaps that need to be immediately addressed and provide potential solutions to these issues. Herein, we examined the current literature on the sources, occurrences, and behaviors of MNPs in the human body as well as their potential health risks. Furthermore, we identified key knowledge gaps that must be resolved to comprehensively assess the effects of MNPs on human health. Additionally, we addressed that the complexity of MNPs and the lack of efficient analytical methods are the main barriers impeding current investigations on MNPs in the human body, necessitating the development of a standard and unified analytical method. Finally, we highlighted the need for interdisciplinary studies from environmental, biological, medical, chemical, computer, and material scientists to fill these knowledge gaps and drive further research. Considering the inevitability and daily occurrence of human exposure to MNPs, more studies are urgently required to enhance our understanding of their potential negative effects on human health.

Simulated gastrointestinal digestion of polylactic acid (PLA) biodegradable microplastics and their interaction with the gut microbiota

The accumulation of microplastics (MPs) in the environment as well as their presence in foods and humans highlight the urgent need for studies on the effects of these particles on humans. Polylactic acid (PLA) is the most widely used bioplastic in the food industry and medical field. Despite its biodegradability, biocompatibility, and "Generally Recognized As Safe" (GRAS) status, recent animal model studies have shown that PLA MPs can alter the intestinal microbiota; however, to date, no studies have been reported on the possible gut and health consequences of its intake by humans. This work simulates the ingestion of a realistic daily amount of PLA MPs and their pass through the gastrointestinal tract by combining the INFOGEST method and the gastrointestinal simgi® model to evaluate possible effects on the human colonic microbiota composition (16S rRNA gene sequencing analysis) and metabolic functionality (lactic acid and short-chain fatty acids (SCFA) production). Although PLA MPs did not clearly alter the microbial community homeostasis, increased Bifidobacterium levels tended to increase in presence of millimetric PLA particles. Furthermore, shifts detected at the functional level suggest an alteration of microbial metabolism, and a possible biotransformation of PLA by the human microbial colonic community. Raman spectroscopy and field emission scanning electron microscopy (FESEM) characterization revealed morphological changes on the PLA MPs after the gastric phase of the digestion, and the adhesion of organic matter as well as a microbial biofilm, with surface biodegradation, after the intestinal and colonic phases. With this evidence and the emerging use of bioplastics, understanding their impact on humans and potential biodegradation through gastrointestinal digestion and the human microbiota merits critical investigation.

Response of moulting genes and gut microbiome to nano-plastics and copper in juvenile horseshoe crab Tachypleus tridentatus

Nanoplastics (NPs) and heavy metals are typical marine pollutants, affecting the gut microbiota composition and molting rate of marine organisms. Currently, there is a lack of research on the toxicological effects of combined exposure to horseshoe crabs. In this study, we investigated the effects of NPs and copper on the expression of molt-related genes and gut microbiome in juvenile tri-spine horseshoe crabs Tachypleus tridentatus by exposing them to NPs (100 nm, 104 particles L-1) and/or Cu2+ (10 μgL-1) in seawater for 21 days. Compared with the control group, the relative mRNA expression of ecdysone receptor (EcR), retinoid x receptor (RXR), calmodulin-A-like isoform X1 (CaM X1), and heat shock 70 kDa protein (Hsp70) were significantly increased under the combined stress of NPs and Cu2+. There were no significant differences in the diversity and abundance indices of the gut microbial population of horseshoe crabs between the NPs and/or Cu2+ groups and the control group. According to linear discriminant analysis, Oleobacillus was the most abundant microorganism in the NPs and Cu2+ stress groups. These results indicate that exposure to either NPs stress alone or combined NPs and Cu2+ stress can promote the expression levels of juvenile molting genes. NPs exposure has a greater impact on the gut microbial community structure of juvenile horseshoe crabs compared to Cu2+ exposure. This study is helpful for predicting the growth and development of horseshoe crabs under complex environmental pollution.

Microplastics exposure and immunologic response

OBJECTIVE

To assess the impact of microplastics (MPs) on human health.

DATA SOURCE

The authors conducted a non-systematic review of articles published in English, Portuguese, French, and Spanish in the last decade in the following databases: PubMed, Google Scholar, EMBASE, and SciELO. The keywords used were: microplastics OR nanoplastics OR marine litter OR toxicology OR additives AND human health OR children OR adults.

DATA SUMMARY

MPs are a group of emerging contaminants that have attracted scientific interest and societal attention in the last decade due to their ubiquitous detection in all environments. Humans can primarily be exposed to MPs and nanoplastics via oral and inhalation routes, but dermal contact cannot be overlooked, especially in young children. The possible toxic effects of plastic particles are due to their potential toxicity, often combined with that of leachable additives and adsorbed contaminants.

CONCLUSIONS

Unless the plastic value chain is transformed over the next two decades, the risks to species, marine ecosystems, climate, health, economy, and communities will be unmanageable. However, along with these risks are the unique opportunities to help transition to a more sustainable world.

Interactions of Nanomaterials with Gut Microbiota and Their Applications in Cancer Therapy

Cancer treatment is a challenge by its incredible complexity. As a key driver and player of cancer, gut microbiota influences the efficacy of cancer treatment. Modalities to manipulate gut microbiota have been reported to enhance antitumor efficacy in some cases. Nanomaterials (NMs) have been comprehensively applied in cancer diagnosis, imaging, and theranostics due to their unique and excellent properties, and their effectiveness is also influenced by gut microbiota. Nanotechnology is capable of targeting and manipulating gut microbiota, which offers massive opportunities to potentiate cancer treatment. Given the complexity of gut microbiota-host interactions, understanding NMs-gut interactions and NMs-gut microbiota interactions are important for applying nanotechnologies towards manipulating gut microbiota in cancer prevention and treatment. In this review, we provide an overview of NMs-gut interactions and NMs-gut microbiota interactions and highlight the influences of gut microbiota on the diagnosis and treatment effects of NMs, further illustrating the potential of nanotechnologies in cancer therapy. Investigation of the influences of NMs on cancer from the perspective of gut microbiota will boost the prospect of nanotechnology intervention of gut microbiota for cancer therapy.