Microplastics (MPs) and nanoplastics (NPs) are characterized by small particle size, strong adsorption capacity, and resistance to degradation. Therefore, MPs are not only widely present in nature but also pose long-term pollution risks to organisms through pathways such as the digestive tract, respiratory tract, and skin contact, and can continuously accumulate upward through the food chain. Studies have found that exposure to MPs alone or in combination with other pollutants can have adverse effects on the body, such as alterations in gut microbiota and neurobehavioral effects. The gut microbiota plays a significant role in many physiological processes and may participate in bidirectional communication with the brain through the microbiota–gut–brain axis, which is associated with the occurrence and development of many neurological and psychiatric diseases. Up to now, few studies have examined the toxic effects and underlying mechanisms of MPs on the microbiota–gut–brain axis. This review synthesizes current advances in the literature concerning microplastic toxicity and its interactions with the microbiota–gut–brain axis, with the aim of promoting further investigation into the adverse effects of MPs on gut microbial composition and neurobehavioral outcomes, elucidating the underlying mechanistic pathways, identifying potential biomarkers and preventive strategies, and informing approaches for environmental and human health protection. Future studies should prioritize environmentally relevant exposure scenarios, standardized characterization of MPs/NPs, longitudinal and mammalian studies, and mechanistic experiments that directly test causality along the microbiota–gut–brain axis.
Hair loss is a common condition that can negatively affect quality of life. This study evaluated the efficacy and safety of a shampoo containing 0.25
Microplastics (MPs), an emerging pollutant, pose negative impacts on aquatic life. Heavy metals released from industrial discharges, pharmaceuticals, agricultural runoff, and other sources also exert adverse impacts on aquatic organisms. Additionally, MPs can adsorb other contaminants from the surrounding environment, thereby increasing their bioavailability. This study focused on the combined toxic effects of polyethylene microplastics (PE-MP) and chromium (Cr) on growth, mortality, heart rate, malformation rate, and swimming behavior of Nile tilapia larvae. Larvae were exposed to control (C), PE-MP (5 mg/L), Cr (10
Phenanthrene is a persistent organic pollutant of ecological concern, and are widely detected in water, sediment, and organisms. This study evaluates the acute toxicity of phenanthrene on juvenile Nile tilapia (Oreochromis niloticus) for 96 h at concentrations of 0, 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mg/L under semi-static conditions. Mortality was recorded at 6 h of interval, and at the end of 96 h, six fish (n = 6) from the survived groups (0, 0.25, 0.5 mg/L) were collected for the evaluation of hematological and histopathological endpoints. Probit test revealed 96 h median lethal concentration (LC50) as 0.579 mg/L. At concentrations of 0.25 and 0.5 mg/L, blood glucose level increased and hemoglobin level declined significantly (p < 0.05), indicating systemic stress. Furthermore, a dose-dependent increment of erythrocytic cellular (i.e. tear drop, twin, fusion, elongated and spindle) and nuclear (i.e. micronucleus, binucleus, notched nuclei, nuclear bud and nuclear bridge) abnormalities was clearly evident in the studied fish, indicating possible cytotoxic and genotoxic effects. Histopathological examination demonstrated severe structural anomalies in the gills of exposed fish, including degeneration of secondary lamellae, clubbing, telangiectasis, compared to the control group. Intestine showed two distinct types of histological outcomes. Morphology of intestine remained unaffected; however, pathological changes were most pronounced at 0.5 mg/L starting from 0.25 mg/L including displacement of epithelium from lamina propria and vacuolation. Moreover, hepatic and renal morphological alterations were moderate to severe in fish exposed to phenanthrene at 0.25 and 0.5 mg/L. These findings together indicate phenanthrene as a potent toxicant capable of inducing severe mortality, hematological, and multi-organ dysfunctions in Nile tilapia, which underscores its ecological risk in contaminated aquatic systems.
Glyphosate is a widely used herbicide, and its potential effects on non-target microbial communities remain a concern. This study examined the effects of chronic glyphosate exposure on the intestinal microbiome of a well established aquatic model fish, zebrafish (Danio rerio), an established vertebrate model for ecotoxicological research. Zebrafish were exposed to sublethal concentrations of glyphosate for 21 days, comprising a low-dose group (T2ZG, 4.89 mg/L) and a high-dose group (T1ZG, 16.32 mg/L), after which the gut microbiota was characterized by 16S rRNA gene sequencing. Alpha-diversity indices did not differ significantly among the groups, whereas beta-diversity analysis revealed significant shifts in microbial community composition following glyphosate exposure. Taxonomic profiling demonstrated dose-dependent alterations in bacterial abundance, including enrichment of stress-tolerant taxa such as Mycobacterium and changes in the relative abundance of genus Cetobacterium. Dose-dependent changes in microbial pathways were observed using PICRUSt functional prediction, particularly in lipid metabolism and xenobiotic degradation. Analysis of the co-occurrence networks revealed that the connectivity and stability of the microbial community decreased with increasing glyphosate concentration. Sublethal glyphosate exposure alters the gut microbial equilibrium in zebrafish, potentially affecting host health and ecological integrity.
