Search Results (815)

Ants act as keystone species in terrestrial ecosystems, providing important ecosystem services. The large-scale production and application of GO constitute a predominant contributor to its inevitable environmental dispersion. Most GO toxicity studies have focused on plants, animals, and microorganisms, with limited research on ground-dwelling ants. In the study, we used Camponotus japonicus as a model to investigate the toxic effects of GO on ants by integrating physiological characteristics, gut microbiota and transcriptome profiling. Results showed that GO exposure induced mitochondrial dysfunction, as evidenced by mitochondrial ROS accumulation and elevated mitochondrial membrane permeability. Physiological assessments revealed that GO exposure induced oxidative stress. Specifically, GO treatment significantly suppressed superoxide dismutase (SOD) and catalase (CAT) activities, while enhancing peroxidase (POD) and carboxylesterase (CarE) activities and increasing the levels of malondialdehyde (MDA) and trehalose. Gut microbiota analyses showed that GO remarkably reduced the relative abundance of beneficial bacterial symbionts (e.g., Candidatus Blochmannia) and destabilized the whole community structure. Furthermore, transcriptome profiling revealed 680 differentially expressed genes (DEGs) in the ants after GO exposure, most of which were significantly enriched in pathways associated with oxidative phosphorylation. This study suggests that GO may compromise ant-mediated ecosystem function and provides a reference for understanding the environmental risks of GO. Our findings also offer new insights for protecting the ecosystem services of ants. Full article

Silver nanoparticles (AgNPs) are increasingly applied in agriculture and related technologies due to their antimicrobial properties, yet their interactions with soil-associated organisms and microbial communities remain insufficiently characterized. This study examined the effects of AgNP exposure (10.85 mg/L) on trace element accumulation and gut bacterial communities of the earthworm Eisenia fetida under two substrate conditions (horticultural substrate and compost). High-throughput 16S rRNA gene sequencing revealed substrate-dependent shifts in microbial community structure following AgNP exposure. Several bacterial taxa, including Proteobacteria, Gammaproteobacteria, Bacilli, Streptococcus sp., and Staphylococcus sp., exhibited pronounced numerical declines, indicating sensitivity to AgNPs, whereas Actinobacteria and Bacteroidetes showed comparatively higher relative abundances, suggesting greater tolerance. Compost partially mitigated the inhibitory effects of AgNPs on gut microbiota. Concurrently, AgNP exposure altered trace element accumulation patterns in earthworm tissues, highlighting interactions between silver uptake and elemental homeostasis. Collectively, these findings demonstrate that AgNPs can induce taxon- and substrate-specific responses in earthworm-associated microbial communities and metal accumulation, providing insight into potential ecological consequences of nanoparticle use in agricultural systems. Full article

Gut microbes play a crucial role in regulating physiological processes such as host energy metabolism, nutrient absorption, and environmental adaptation. The predicted functions of gut microbes can be influenced by many factors, both extrinsic and intrinsic to the hosts. The plateau pika is a key species in the alpine ecosystem of the Qinghai–Tibet Plateau. Previous research on the plateau pika primarily examined how extrinsic factors affected its gut microbiota. However, studies on intrinsic factors are scarce. Here, we used live-trapping to capture plateau pikas and collect cecum contents. Using metagenomic sequencing of cecum content samples, we characterized and compared the gut microbial composition and predicted function of plateau pika in adult (n = 9) and juvenile (n = 9) populations. The results indicated that Bacillota and Bacteroidete were the major bacterial phyla. The core gut microbial genera were the same, but the relative abundance of Oscillospira in juveniles was significantly lower than that in adults. The changes in the proportion of cellulose-degradation-related bacterial communities in juveniles suggest that they tend to choose low-fiber diets. In this study, we found no significant differences in the gut microbial composition and diversity, KEGG level 1 metabolic pathways, or CAZy class level between adult and juvenile plateau pikas. In total, the composition and predicted functions of cecal microorganisms in juvenile and adult male plateau pikas were not different. Regarding KEGG level 2 metabolic pathways, the juvenile group had a higher relative abundance of metabolic pathways for cofactors and vitamins, terpenoids, and polyketides, whereas the adult group had a higher relative abundance of energy metabolism. However, the resulting differences remain unclear. Therefore, future research should validate the above findings on a broader spatio-temporal scale and conduct cross-species comparisons to construct a microbial ecological framework for the health management of plateau wild animals. Full article

Colostrum harbors a highly diverse microbial community, predominantly composed of genera such as Staphylococcus, Streptococcus, Lactobacillus, Bifidobacterium, and Enterococcus. The composition and diversity of this microbiota are influenced by maternal factors—including age, body mass index, lactation activity, stress levels, and gestational diabetes—as well as external factors such as mode of delivery, antibiotic exposure, diet, and geographic location. This microbial community plays a critical role in maternal and neonatal health by contributing to early gut colonization, supporting digestion, promoting immune system development, and protecting against pathogenic microorganisms through mechanisms such as antimicrobial peptide production by lactic acid bacteria. The primary aim of this study was to evaluate the impact of mode of delivery on colostrum microbiota by comparing mothers who delivered vaginally with those who underwent cesarean section. Colostrum samples from 15 mothers were subjected to DNA extraction, high-throughput sequencing, and bioinformatic analyses to characterize microbial composition and predicted functional profiles. Although substantial inter-individual variability was observed, no statistically significant differences were detected in overall microbial diversity or community structure between the two delivery groups. However, distinct bacterial taxa and functional characteristics were identified that were specific to each mode of delivery, suggesting subtle delivery-related influences on colostrum microbiota composition. Full article

The insect gut microbiome contributes to various host physiological processes and behaviors, such as digestion, nutrient absorption, immunity, mate choice, and fecundity. The social environment can shape gut microbial communities. Mixed-sex vs. female-only rearing is an important social context because it differs in exposure to the opposite sex and mating opportunities, which may in turn affect female physiology that may influence their gut microbiome. Despite the growing recognition of these social-microbial interactions, most studies have relied on 16S rRNA amplicon sequencing or qPCR, which provide only coarse taxonomic resolution and limited functional insight. In this study, we used whole-genome shotgun metagenomics to examine changes in microbial diversity and functional gene composition in the female field cricket Teleogryllus occipitalis (Serville) (Orthoptera: Gryllidae) reared under two social conditions: mixed-sex rearing and female-only rearing. Species richness and diversity analyses revealed that community composition separated between females from mixed-sex and female-only rearing. Functional profiling indicated higher relative abundances of genes annotated to nutrient processing and inter-bacterial competition in females from mixed-sex rearing, whereas females from female-only rearing showed relative enrichment of genes annotated to stress resistance and nitrogen fixation. These findings provide a genome-resolved foundation for testing how social rearing conditions covary with gut microbiome composition and functional potential in female crickets. Full article

The rising global burden of colorectal cancer (CRC) has now positioned it as the third most common cancer worldwide. Chemotherapy regimens are known to disrupt the composition of the gut microbiota and lead to long-term health consequences for cancer patients. However, the alteration of gut microbiota by specific chemotherapeutic agents has been insufficiently explored until now. The purpose of this study was to assess changes in the gut microbiota following treatment with VERU-111 as a chemotherapy agent for the treatment of CRC. We thus performed a metagenomic study using 16S rRNA gene amplicon sequencing of fecal samples from different experimental groups in the azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced murine model of CRC. To predict the functional potential of microbial communities, we used the resulting 16S rRNA gene sequencing data to perform Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. We found that the administration of VERU-111 led to a restructured microbial community that was characterized by increased alpha and beta diversity. Compared to the mice treated with DSS alone, VERU-111 treatment significantly increased the relative abundance of several bacterial species, including Verrucomicrobiota species, Muribaculum intestinale, Alistipes finegoldii, Turicibacter, and the well-known gut-protective bacterial species Akkermansia muciniphila. The relative abundance of Ruminococcus, which is negatively correlated with immune checkpoint blockade therapy, was diminished following VERU-111 administration. Overall, this metagenomic study suggests that the microbial shift after administration of VERU-111 is associated with suppression of several metabolic and cancer-related pathways that might, at least in part, facilitate the suppression of CRC. These favorable shifts in gut microbiota suggest a novel therapeutic dimension of using VERU-111 to treat CRC and emphasize the need for further mechanistic exploration. Full article

Tomato leafminer (Tuta absoluta) significantly affects tomato (Solanum lycopersicum) and eggplant (Solanum melongena) crops worldwide, with its feeding patterns being closely associated with its gut microbiota. We aimed to compare the cultivable gut bacteria of T. absoluta larvae fed on tomato and eggplant to investigate their role in host adaptation. Gut bacteria were cultivated on Luria–Bertani broth, nutrient agar, and Brain Heart Infusion media under different temperature conditions, followed by morphology- and 16S rRNA-based identification. Notably, both feeding groups revealed distinct gut bacterial community structures. Tomato-fed larvae harbored bacteria spanning eight species, five genera, four families, and two phyla. In contrast, eggplant-fed larvae exhibited greater microbial diversity, encompassing 15 species, 10 genera, 9 families, and 3 phyla, including unique genera such as Pseudomonas and Pectobacterium, which was attributed to the host plant contribution. Enterococcus mundtii was the most dominant bacterium, and species such as Bacillus wiedmannii and Micrococcus luteus were most thermotolerant. Overall, these findings highlight the importance of multi-condition culture approaches for thoroughly characterizing insect gut microbiota and underscore the role of host plants in pest adaptability by modulating gut microbial communities, providing new insights for developing sustainable control strategies utilizing “plant–insect–microorganism” interactions. Full article

Habitat micromodification poses significant challenges to wildlife, necessitating adaptive responses. This study aimed to investigate how such habitat alterations affect the dietary intake and gut microbiota of Père David’s deer (Elaphurus davidianus). A total of 25 fresh fecal samples were collected from Père David’s deer through non-invasive sampling in Tianjin Qilihai Wetland across three distinct phases of habitat micromodification: pre-change (N = 10), under-change (N = 8), and post-change (N = 7). Dietary composition was analyzed via microscopic identification of plant residues, and gut microbiota structure was characterized using 16S rRNA high-throughput sequencing. Results showed that the diet shifted significantly across phases, with 33 plant species from 20 families identified. Meanwhile, the core gut microbiota remained structurally stable. The phyla Firmicutes and Bacteroidota consistently dominated, despite fluctuations in some specific bacterial genera. Functional prediction indicated minimal change in core microbial metabolic pathways. Correlation analysis suggested that key dietary plants were linked to the abundance of specific, functionally relevant microbial taxa. In conclusion, this study demonstrates that the gut microbiota of Père David’s deer exhibits marked resilience to dietary shifts induced by habitat micromodification. This stability is underpinned by functional redundancy within the microbial community and the consistent intake of fibrous plants, representing a key adaptive mechanism. Our findings highlight that integrating non-invasive monitoring of diet and microbiota can effectively assess the adaptive capacity of endangered ungulates to managed habitat change, thereby informing more resilient conservation strategies. Full article

Analyzing the composition and structure of the gut bacterial community in Antheraea pernyi is essential for improving its economic traits, as well as for understanding gut bacteria–host interactions in lepidopteran insects. This study utilized the Illumina MiSeq PE 300 platform to conduct 16S rRNA gene sequencing for a comparative analysis of gut bacterial community in laboratory-reared and field-released (spring and autumn) Antheraea pernyi larvae of the same strain. The study revealed the specific effects of rearing environment and seasonal variation on the structural and functional dynamics of the larval gut bacterial communities. The composition of the dominant gut bacteria varied significantly with rearing environment and season. Laboratory-reared and spring field-released groups exhibited similar bacterial community structures, whereas the autumn field-released group showed a significant trend toward specialization, characterized by enrichment of specific bacterial taxa. Linear discriminant analysis effect size identified statistically significant biomarkers across samples. Taxonomic analysis revealed that Actinomycetota, Actinobacteria, Mycobacteriales, Dietziaceae, and Dietzia were characteristic of the gut bacteria profile in spring field-released, Lactobacillales, Enterococcaceae, and Enterococcus were enriched in the autumn field-released group, and the laboratory-reared group exhibited a relative dominance of Alphaproteobacteria. Functional prediction indicated that gut bacterial community structure likely influences its metabolic potential, which may suggest an adaptive response of the Antheraea pernyi to distinct ecological environments. This study provides important insights into the highly complex nature of insect-microbe interactions. Full article

Entomopathogenic fungi are promising alternatives to synthetic insecticides for the control of vector species, notably the arbovirus vector, Aedes aegypti. The influence of intrinsic mosquito midgut microbiota on host susceptibility to fungal infection and subsequent physiological processes remains poorly understood. Here we treated female Ae. aegypti with the broad-spectrum antibiotic carbenicillin to reduce gut bacterial populations, then exposed them to Metarhizium anisopliae conidia. Female Ae. aegypti offered carbenicillin and then sprayed with fungi had significantly lower survival rates (38.9% ± 1.15) compared to non-antibiotic-treated mosquitoes sprayed with fungus (68.9% ± 0.58). To monitor the kinetics of microbial community recovery, mosquitoes were challenged with conidia at 0, 3, 6, and 9 days following antibiotic removal from the diet. Reduced survival persisted through the 6-day period (survival rates 37.8% to 45.6%), with a significant increase in survival observed 9 days post-antibiotic removal (58.9% vs. control 63.3%), which coincided with recovery of gut bacterial populations. Additionally, antibiotic and fungal treatments reduced egg production, larval eclosion, and pupal formation. These results demonstrate that gut bacteria contribute to mosquito defense against fungal pathogens and support normal reproductive and developmental functions. Understanding the interplay between gut microbiota and entomopathogenic fungi may enhance biological control approaches. Full article

During the last ten years, the scientific community has increasingly acquired greater knowledge of the importance of oral microbiota, in general, for the physical condition of humans. Not only oral diseases, related to oral dysbiosis, are examined, but also several systemic inflammatory degenerative diseases induced by this condition. This narrative review aims to shed light on the communication mechanisms between the oral cavity and different mucosal compartments, and to explain how the changes in microorganisms may alter their balance, leading to disease. Many potential pathogenic bacteria can induce oral dysbiosis, among them Porphyromonas gingivalis and Fusobacterium nucleatum are the most explored; however, other bacterial species such as Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans and Filifactor alocis are able to give rise to local and systemic diseases through the release of toxins. The two-way communication system between the gastrointestinal tract and the central nervous system, known as the gut–brain axis, is strongly influenced by the gut microbiota and can ultimately be studied even more broadly and in depth if we consider the influence of the oral microbiota on this axis. Taste receptors’ activity also has a significant role, being able to affect a subject’s food choice by interacting with the microbiota. Qualitative and quantitative alterations in microorganisms existing in the main mucosal compartments may easily lead the host to develop systemic degenerative inflammatory diseases. Full article

The human gut microbiota plays a key role in neurochemical communication, especially through the gut–brain axis. There is growing evidence that the gut microbiota influences dopamine metabolism through both production and consumption mechanisms. Two key bacterial enzymes are central to this process: tyrosine decarboxylase (TDC), which primarily catalyzes the decarboxylation of tyrosine to tyramine but can also act on L-DOPA to produce dopamine in certain bacterial strains, and aromatic L-amino acid decarboxylase (AADC), which can convert precursors such as L-DOPA, tryptophan, or 5-hydroxytryptophan into bioactive amines including dopamine, tryptamine, and serotonin. Identifying the bacterial families corresponding to TDC and AADC enzymes opens new avenues for clinical intervention, particularly in neuropsychiatric and neurodegenerative disorders, such as Parkinson’s disease. Moreover, elucidating strain-specific microbial contribution and host-microbe interactions may enable personalized therapeutic strategies, such as selective microbial enzyme inhibitors or tailored probiotics, to optimize dopamine metabolism. Emerging technologies, including biosensors and organ-on-chip platforms, offer new tools to monitor and manipulate microbial dopamine activity. This article explores the bacterial taxa capable of producing or consuming dopamine, focusing on the enzymatic mechanisms involved and the methodologies available for studying these processes in vivo. Full article

This study aims to investigate the differences in microbial community structure between fast-growing (FG) and slow-growing (SG) short-finned eels, Anguilla bicolor pacifica, using high-throughput 16S rDNA sequencing, and to evaluate the potential probiotic properties of Bacillus tropicus isolated from eel intestinal microbiota to enhance growth performance. High-throughput 16S rDNA sequencing revealed no significant differences in the α-diversity between FG and SG eels. Bacterial genera such as Cetobacterium, Clostridium, and Bacteroides were predominant in both groups, with Edwardsiella, Aeromonas, and Fusobacterium being more abundant in SG eels, suggesting a higher presence of potential pathogens. The analysis of the relative abundance of gut microorganisms revealed that SG eels harbored higher levels of potentially pathogenic bacteria, including Edwardsiella tarda and Aeromonas jandaei. In contrast, FG eels exhibited a greater abundance of the potential probiotic B. tropicus. Six strains of bacteria with relative abundance were isolated from the FG group, displaying superior digestive enzyme activity, including protease, lipase, amylase, cellulase, xylanase, and phytase, particularly strain FG2. Phylogenetic analysis confirmed that FG2 was closely related to B. tropicus. A virulence assessment confirmed the non-pathogenic nature of B. tropicus FG2, supporting its probiotic potential. Furthermore, feeding eels a diet supplemented with B. tropicus FG2 significantly enhanced growth performance, as evidenced by increased final weight percentages of weight gain and total production per tank (p < 0.05), while the proximate composition of the dorsal muscle showed an increase in lipid content (p < 0.05). These findings highlight B. tropicus FG2 as a promising probiotic for aquaculture applications. Full article

Diet and living environments exert a profound influence on gut microbiota composition. This study presents the first comprehensive characterization of fecal bacteria, fungi, and protozoa in wild (WA) (n = 10) and captive (DA) (n = 11) wapiti (Cervus canadensis) in China. Results reveal distinct microbial profiles between the two groups. In wild wapiti, Escherichia-Shigella and UCG-005 were the dominant bacterial genera, while Succinivibrio and Treponema predominated in captive individuals. Among fungi, Agaricus and Preussia were most abundant in wild wapiti, whereas Xeromyces was identified in captive ones. For protozoa, Heteromita was the primary genus in wild wapiti, while Heteromita, Entamoeba, and Eimeria were the main genera in captive wapiti. Functional predictions further underscored these differences. In wild wapiti, bacterial and fungal functions were primarily associated with carbon metabolism and the pyruvate cycle, with mutualistic interactions prevailing among bacteria, fungi, and protozoa. Conversely, captive wapiti exhibited functional profiles centered on lipopolysaccharide and amino acid metabolism, also characterized by mutualistic coexistence among microbial communities. These findings highlight the significant impact of dietary composition on the gut microbiome. In summary, wild wapiti appear to possess a superior capacity for plant fiber utilization. These findings provide valuable data for the health management of farmed wapiti and their adaptability in natural habitats. Full article

The ruminant gastrointestinal tract hosts a complex microbial ecosystem vital for nutrient absorption, with each segment displaying distinct morphological and microbial compositional features compared to monogastric animals. While most studies rely on fecal samples, these fail to capture region-specific variations, limiting insight into microbe–physiology adaptations. In this study, we investigated Elaphodus cephalophus by measuring circular, longitudinal, and mucosal layer thickness across intestinal segments and by profiling bacterial and fungal communities via 16S and its rRNA sequencing. The results found that the stomach had the thickest circular (484.2 μm) and longitudinal (385.2 μm) muscle layers among all gastrointestinal segments. The thickness of the circular and longitudinal muscle layers in the stomach and duodenum showed a highly consistent variation trend (r > 0.74). Bacterial diversity was highest in the stomach and lowest in the ileum; cecal and rectal communities were similar but distinct from those in the duodenum, ileum, and stomach. Firmicutes and Bacteroidota dominated the bacterial phyla. Fungal abundance and diversity peaked in the cecum and were lowest in the stomach; Ascomycota was overall dominant, whereas Basidiomycota was most abundant in the duodenum. This study provides baseline descriptive data on the gastrointestinal muscle layer morphology and gut microbiota of Elaphodus cephalophus, establishing a basis for further study. Full article