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Metagenomic Insights Into Microbial Diversity of Tea Rhizosphere of the Kangra Valley.

This study provides the first metagenomic assessment of microbial diversity from the tea rhizosphere of the Kangra valley. Tea rhizosphere soil samples were collected from 4 locations (Dharamshala, Baijnath, Palampur, and Joginder Nagar) of the Kangra valley. DNA extracts of rhizosphere samples were analysed for bacterial and Archaeal diversity using amplicon sequencing (V3-V4) region of the 16S rRNA gene and Fungal diversity using ITS1 and ITS2 regions. Baijnath and Palampur samples showed the highest bacterial richness, while Dharamshala and Palampur had the highest fungal richness. Proteobacteria was a dominant phylum in all the rhizosphere samples, followed by Firmicutes, Actinobacteria, Acidobacteria, and Bacteroidetes. A total of 11 fungal phyla were identified among all the locations, with abundance of Ascomycota and Basidiomycota. For the Archaea domain, uncultured archaeon and Aeropyrum camini were the most common found among all the locations. A small fraction (<&#x2009;0.5%) of Bacillus and Pseudomonas species were observed among all the locations. Alpha and beta diversity indices displayed notable differences within and between microbial diversities. Soil factors were variably associated with microbial diversity, with nitrogen positively aligned with fungal diversity, while EC and K were associated with Archaeal diversity. Soil pH and OM% showed moderate associations with bacterial diversity. These findings provided valuable and comprehensive insights into tea rhizosphere microbial ecology and could be used to better understand microbial functions and their role in plant health.

Rhizosphere

Gut microbial diversity at baseline conditions the clinical, microbiome, and metabolic response to paraprobiotic Lactiplantibacillus plantarum LRCC5282 in overweight adults.

The gut microbiota is increasingly recognized as a target for obesity management; however, whether baseline gut microbial diversity conditions responsiveness to microbiota-targeted interventions remains unclear. We aimed to investigate whether baseline gut microbial diversity is associated with responsiveness to a paraprobiotic derived from Lactiplantibacillus plantarum LRCC5282 (LP5282-P) in overweight adults. In a 12-week, randomized, double-blind, placebo-controlled, multicenter trial of 120 overweight adults, LP5282-P produced no significant between-group differences in any clinical outcome across the overall per-protocol population. However, in the low-diversity subgroup, LP5282-P was associated with significant reductions in body weight, body mass index, and circulating leptin levels. These clinical changes were accompanied by compositional shifts in the gut microbiota, including higher relative abundances of Christensenellaceae, Faecalibacterium, and Alistipes. Fecal metabolite profiles showed elevated acetate and butyrate concentrations and altered bile acid composition. Within the low-diversity subgroup, changes in the relative abundances of Akkermansia and Eubacterium were inversely correlated with changes in body weight, body fat mass, and leptin levels. In contrast, the high-diversity subgroup exhibited no consistent response across the outcome domains examined. Overall, baseline gut microbial diversity was associated with differential responsiveness to LP5282-P, supporting its potential use as a stratification variable in future microbiota-targeted intervention trials. Further studies integrating direct measures of microbial activity and host response are warranted to elucidate the biological pathways underlying this diversity-dependent responsiveness. Trial registration: Clinical Research Information Service (CRIS), KCT0008119.

Humans

Microbial diversity: the essential foundation for life on our planet.

The biological basis of life on Earth is microbial diversity that ensures human health, agricultural productivity, ecological balance, and ecosystem functioning. Microorganisms enable ecosystem restoration through bioremediation, maintain soil fertility, support plant growth, manage vital biogeochemical cycles, and contribute to climate resilience. Precision probiotics, postbiotics, faecal microbiota transplantation, and personalized microbiome medicine are the examples of emerging microbiome-based therapies that offer promising therapeutic opportunities. In humans, the gut microbial community is essential for immune regulation, metabolism, and disease prevention. In terrestrial ecological systems, interactions between plants, fungi, bacteria, and other soil microorganisms improve carbon sequestration, nutrient cycling, stress resilience, and sustainable agricultural productivity in the given effects of climate change. Emerging uses in agriculture, environmental restoration, and medicine are made possible by advancements in multi-omic techniques, synthetic microbial genomes, microbiome engineering, and artificial intelligence. Considering these developments, issues with ecological complexity, long-term validation, standardization, and field scale application still exist. Therefore, preserving microbial diversity is important for conserving ecological resilience and strengthening the One Health framework, which highlights the mutual dependance of health of animal, human, plant, and environment. This review summarizes what has been discovered about ecological and biomedical relevance of microbiome, identifies important research gaps, highlighting emerging technologies, and evaluates potential future directions for using microbiome to support planetary sustainability.

Bioremediation

Microbial diversity, functional activities, and safety risks in fermented tea: a comprehensive review.

Microbial fermented teas are gaining global popularity due to their unique sensory profiles and health benefits. The quality and safety of these products are governed by complex microbial ecosystems that orchestrate the biotransformation of tea leaf components. This review addresses a critical paradox in the field: the same microbial activities that generate desirable bioactive metabolites, such as theabrownins and organic acids, also create ecological niches for mycotoxigenic fungi, posing significant health risks from contaminants like ochratoxin A, citrinin, and aflatoxins. While extensive research has cataloged the microbial diversity in these systems, a comprehensive framework linking processing environments to microbial community assembly, functional outcomes, and quantifiable safety risks remains elusive. This review systematically bridges this gap by synthesizing current knowledge on the microbial consortia-dominated by Aspergillus, Penicillium, Bacillus, and Lactiplantibacillus species-that drive tea fermentation. We critically analyze their functional roles in enhancing flavor, bioactivity, and potential probiotic activity while simultaneously evaluating the mechanisms of mycotoxin production and accumulation. By integrating microbial ecology, biochemistry, and food safety, we propose a forward-looking perspective focused on transitioning the industry from traditional, spontaneous fermentation to modern, controlled biotechnological processes. This approach, centered on the use of defined starter cultures, predictive modeling, and active biocontrol strategies, provides a roadmap for ensuring the consistent quality and safety of fermented tea products, ultimately unlocking their full potential as high-quality functional foods.

Tea

A deep metagenomic atlas of Qinghai-Xizang Plateau lakes reveals their microbial diversity and salinity adaptation mechanisms.

The Qinghai-Xizang Plateau (QXP), harboring the planet's highest density of plateau lakes, offers an exceptional biogeographic environment for studying extremophilic microbial communities and their adaptation to salinity. Through deep metagenomic sequencing, we construct the Qinghai-Xizang Lake Sediment Genome (QXLSG) catalog, a high-resolution genomic catalog comprising 5,866 metagenome-assembled genomes (MAGs), 58.16 million non-redundant protein encoding genes, and 19,008 biosynthetic gene clusters. Notably, 80.78% of the 2,742 species-level MAGs represent undescribed taxa, significantly expanding the known microbial diversity. Salinity emerges as the primary environmental factor influencing microbial community. Functional annotation highlights that the "salt-out" strategy, particularly the uptake of glycine betaine, is the main mechanism for salinity tolerance. This strategy is prevalent in both hypersaline lake communities and the dominant microbial phyla. Overall, this study provides a crucial genetic resource for future bioprospecting and deepens our understanding of the fundamental mechanisms of microbial adaptation to extreme saline environments.

Lakes

Microbial diversity and metabolic pathways linked to benzene degradation in petrochemical-polluted groundwater.

The rapid advance in shotgun metagenome sequencing has enabled us to identify uncultivated functional microorganisms in polluted environments. While aerobic petrochemical-degrading pathways have been extensively studied, the anaerobic mechanisms remain less explored. Here, we conducted a study at a petrochemical-polluted groundwater site in Henan Province, Central China. A total of twelve groundwater monitoring wells were installed to collect groundwater samples. Benzene appeared to be the predominant pollutant, detected in 10 out of 12 samples, with concentrations ranging from 1.4&#xa0;&#x3bc;g/L to 5,280&#xa0;&#x3bc;g/L. Due to the low aquifer permeability, pollutant migration occurred slowly, resulting in relatively low benzene concentrations downstream within the heavily polluted area. Deep metagenome sequencing revealed Proteobacteria as the dominant phylum, accounting for over 63&#xa0;% of total abundances. Microbial &#x3b1;-diversity was low in heavily polluted samples, with community compositions substantially differing from those in lightly polluted samples. dmpK encoding the phenol/toluene 2-monooxygenase was detected across all samples, while the dioxygenase bedC1 was not detected, suggesting that aerobic benzene degradation might occur through monooxygenation. Sequence assembly and binning yielded 350 high-quality metagenome-assembled genomes (MAGs), with 30 MAGs harboring functional genes associated with aerobic or anaerobic benzene degradation. About 80&#xa0;% of MAGs harboring functional genes associated with anaerobic benzene degradation remained taxonomically unclassified at the genus level, suggesting that our current database coverage of anaerobic benzene-degrading microorganisms is very limited. Furthermore, two genes integral to anaerobic benzene metabolism, i.e, benzoyl-CoA reductase (bamB) and glutaryl-CoA dehydrogenase (acd), were not annotated by metagenome functional analyses but were identified within the MAGs, signifying the importance of integrating both contig-based and MAG-based approaches. Together, our efforts of functional annotation and metagenome binning generate a robust blueprint of microbial functional potentials in petrochemical-polluted groundwater, which is crucial for designing proficient bioremediation strategies.

Groundwater

Plant genetic and root-associated microbial diversity modulate Lactuca sativa responsiveness to a soil inoculum under phosphate deficiency.

Microbial-based approaches offer a promising strategy to decrease the use of chemical fertilizers in agriculture. Among them, arbuscular mycorrhizal fungi (AMF), which extend root surface area and enhance phosphate uptake, and phosphate-solubilizing bacteria (PSB) are particularly relevant. However, their effectiveness depends strongly on plant genetic diversity. To identify genetic markers underlying plant responses to beneficial soil microbes, we studied a panel of 128 fully sequenced Lactuca sativa varieties under controlled phosphate-starvation conditions and treated with AMF and PSB. Lettuce genetic variation showed a strong effect on physiological and morphological responses to microbial inoculation. Genome-wide association studies identified specific genomic regions associated with changes in leaf phosphate content and shoot biomass following treatment. Beyond genetic factors, we observed shifts in fungal &#x3b2;-diversity and increased bacterial &#x3b1;-diversity associated with phenotypic variation. We also identified 44 amplicon sequence variants associated with agriculturally relevant traits. Among these, six bacterial strains were experimentally validated through in vitro and pot experiments for their effects on leaf phosphate concentration and shoot biomass. Overall, we highlighted key genetic, microbial, and physiological mechanisms that may enhance microbial treatments for improved plant phosphate management in lettuce.

16S and ITS metabarcoding

Comparative metagenomic analysis of microbial communities: unravelling microbial communities from the great Rann of Kachchh and coastal saltpans, Gujarat, India.

Hypersaline environments exhibit extreme physiochemical conditions yet support diverse microbial communities. These communities are not only ecologically important but also possess substantial potential for biotechnological exploitation. In this study, we employed a comparative metagenomic approach to assess microbial diversity using two distinct methodologies: (1) direct DNA extraction from raw sediment, and (2) DNA extraction following halophilic enrichment in selective media. Sediment samples were collected from multiple sites and pooled together within the Rann of Kachchh and close-by saltpans and were analysed using 16S rRNA sequencing coupled with bioinformatics pipelines. The results revealed pronounced differences in microbial community composition between the two approaches. Raw sediment samples exhibited significantly higher alpha diversity, with dominant taxa including Halobacterota, Cyanobacteria, and Desulfobacterota, with a substantial proportion of unclassified genera. In contrast, enriched samples were dominated by fast-growing, culturable genera such as Halobacterium, Alkalibacillus, and Candidatus haloredivivus. Principal Coordinate Analysis (PCoA) of beta diversity demonstrated distinct clustering between raw and enriched communities, even within samples from the same sites, underscoring the selective bias introduced by enrichment procedures. These findings emphasise that the methodological choice strongly influences the observed microbial diversity. The aim of this study was to compare microbial community composition in raw hypersaline sediments and enrichment cultures using metagenomic sequencing, to evaluate how enrichment selectively favours specific halophilic taxa. This comparative approach allows identification of the microbial groups that rapidly proliferate under controlled hypersaline conditions, thereby complementing direct environmental sequencing. By integrating both direct and enrichment-based metagenomic approaches, a more comprehensive understanding of microbial community structure in hypersaline environments can be achieved.

India

Environmental Stresses Constrain Soil Microbial Community Functions by Regulating Deterministic Assembly and Niche Width.

Increasing evidence indicates that the loss of soil microbial &#x3b1;-diversity triggered by environmental stress negatively impacts microbial functions; however, the effects of microbial &#x3b1;-diversity on community functions under environmental stress are poorly understood. Here, we investigated the changes in bacterial and fungal &#x3b1;- diversity along gradients of five natural stressors (temperature, precipitation, plant diversity, soil organic C and pH) across 45 grasslands in China and evaluated their connection with microbial functional traits. By quantifying the five environmental stresses into an integrated stress index, we found that the bacterial and fungal &#x3b1;-diversity declined under high environmental stress across three soil layers (0-20&#x2009;cm, 20-40&#x2009;cm and 40-60&#x2009;cm). Metagenomic-based analyses showed that the diversity of functional genes decreased along the stress gradients. High stress enhanced the abundance of genes associated with broad functional categories (e.g., glycolysis/gluconeogenesis, TCA cycle, DNA replication/repair and cell growth/death) but reduced the abundance of genes linked to specialised functional categories (e.g., C, N, S and methane metabolism). Phylogenetic null models and niche analyses indicated that stochastic assembly processes predominated in high-diversity communities, in which bacterial and fungal taxa had a narrow ecological niche. However, in low-diversity communities, deterministic assembly processes were dominant, and taxa had wide niches, correlating with the reduction in gene abundance observed for broad and specialised functional categories. Given the essential role of the microbiome in regulating ecosystem functions, our findings suggest that low-diversity-induced deterministic community assembly processes and a wide niche under high environmental stress may regulate microbial functions. These findings emphasise the ecological mechanisms through which microbial biodiversity regulates terrestrial ecosystem functioning.

Soil Microbiology

Climate and soil shape Daqu wheat quality and seed microbiome via rhizosphere taxa and microbial assembly.

The grain quality and seed microbiome of Daqu wheat are fundamental determinants of Daqu fermentation performance; however, the mechanisms by which cultivation environments influence these traits via rhizosphere microbial communities remain unclear. Bacterial and fungal communities across the bulk soil-rhizosphere-seed continuum of three wheat cultivars grown in four ecoregions were characterized using absolute quantitative amplicon sequencing. The rhizosphere microbiome was treated as a central intermediary, while the response variables were seed microbial diversity and grain-quality traits, including starch content, protein content, and grain hardness. Twelve physicochemical properties of soil and 11 climatic factors were integrated into a multidimensional association framework. Environmental conditions exerted stronger influences on both seed quality traits and microbial diversity than cultivar identity. Distinct regional signatures were also evident in rhizosphere microbiomes, with environmental gradients explaining community variation more effectively than geographic distance. Bacterial communities exhibited greater sensitivity to environmental fluctuations than fungi. Mantel analyses identified available nitrogen, precipitation, and atmospheric pressure as significant drivers of core rhizosphere taxa (P&#xa0;<&#xa0;0.05). iCAMP revealed that stochastic processes predominantly governed rhizosphere bacterial assembly, whereas stochastic and deterministic mechanisms jointly shaped fungal assembly. Partial least squares path modeling further uncovered a rhizosphere-mediated environment-seed cascade, wherein sunlight intensity and duration, atmospheric pressure, and soil nitrogen directly or indirectly affected seed wet gluten content, grain hardness, and seed microbial diversity through their influences on rhizosphere microbiota. Rhizosphere bacterial diversity was negatively associated with seed bacterial diversity (path coefficient&#xa0;=&#xa0;-0.118, P&#xa0;<&#xa0;0.05), indicating that rhizosphere communities may shape seed endophytic bacterial assemblages via environmental filtering and competitive interactions. Collectively, these findings elucidate how environments shape the quality and seed microbiomes of Daqu wheat, providing scientific guidance for optimal site selection and the standardized production of high-quality brewing wheat for industrial Baijiu.

Triticum

Urban soil multifunctionality and seasonal variability of carbon-linked soil traits.

Urban soils can play a significant role in climate change mitigation due to their capacity to store carbon (C) and support microbial biodiversity. In this context, this study evaluated the effects of different fertilization strategies on soil quality, greenhouse gas emissions, and microbial communities in two urban green areas located in the Campania region (Southern Italy) over a three-year period. Mineral fertilization (MIN), micronized vermicompost (CMP), micronized biochar (BCH), vermicompost plus biochar (CMP&#xa0;+&#xa0;BCH) were compared to an unfertilized control (CNT). The results showed that soil physicochemical properties were mainly influenced by site-specific conditions and temporal variability, whereas cation exchange capacity was the soil parameter most responsive to fertilization treatments. The QBS-ar index, used as an indicator of soil biological quality based on soil arthropods, was primarily affected by seasonality, with higher values recorded during spring-summer and no significant effects attributable to fertilization treatments. Vermicompost, BCH, and their combination were associated with lower net soil-vegetation CO2 fluxes and smaller temporal increases in the measured flux compared with the control and mineral fertilization treatments. All treatments exhibited a negative estimated annualized net C balance, indicating that, under the adopted temporal upscaling procedure, the estimated gaseous exchanges exceeded the annual increase in soil organic carbon stocks. Nevertheless, BCH showed the least negative estimated annualized balance. Analyses of microbial diversity revealed that bacterial and fungal communities were mainly shaped by temporal and seasonal factors, while fertilization treatments had limited effects on microbial diversity and community composition. Overall, the findings indicate that biochar showed the most favorable estimated carbon balance and the lowest measured net CO2 fluxes under the conditions investigated. However, its effects on soil biological and microbial properties were limited in the short term, and none of the tested treatments achieved net carbon sequestration. These results suggest that biochar may contribute to climate change mitigation as part of long-term, site-specific management strategies rather than as a standalone solution for improving soil multifunctionality.

Biochar

Contribution of the Brain-Gut-Microbiome Axis to Intergenerational Abnormalities in a Rat Model of Perioperative Neurocognitive Disorder.

BACKGROUND: The brain-gut-microbiome (BGM) axis is a communication network through which the brain and gastrointestinal microbiota interact via neural, hormonal, immune, and gene expression mechanisms. Gut microbiota dysbiosis is thought to contribute to neurocognitive disorders, including perioperative neurocognitive disorder, and to various metabolic abnormalities. Recently, the authors reported that sevoflurane induces neurocognitive deficits in exposed rats as well as their future offspring, with male offspring being particularly affected (intergenerational perioperative neurocognitive disorder). In this study, the authors examined in the same animals whether the intergenerational effects of sevoflurane involve abnormalities in the BGM axis, and whether they are mitigated by paternal pretreatment with either the Na + -K + -Cl - (NKCC1) Cl - transporter inhibitor bumetanide or the glucocorticoid receptor inhibitor RU486, as previously demonstrated for neurocognitive deficits. METHODS: Male Sprague-Dawley rats (F0 generation) were exposed to 2.1% sevoflurane for 3&#x2009;h on postnatal days 56, 58, and 60 (F0M_S group). Before each sevoflurane exposure, distinct experimental groups of F0 males received bumetanide (F0M_BS group) or RU486 (F0M_RS group). These males were mated on postnatal day 90 to produce offspring (F1 generation). Gut microbiota were profiled using 16S rRNA gene sequencing, and brain changes analyzed via RNA sequencing of hippocampal samples. RESULTS: F1 male offspring of F0M_S sires exhibited heightened corticosterone responses to stress, increased inflammatory markers, altered hippocampal transcriptomes, gut microbiota dysbiosis, elevated serum low-density lipoprotein cholesterol levels, and increased body weight. The only abnormality observed in F1 females was a shift in microbial diversity. F0M_S displayed profound alterations in hippocampal transcriptome, while microbial diversity was the only parameter affected in their gut microbiota. Bumetanide or RU486 mitigated most abnormalities, except increased body weight in F1 males. CONCLUSIONS: Paternal sevoflurane exposure in rats induces BGM axis abnormalities, particularly in male offspring, despite the absence of direct anesthetic exposure. Pretreatment with bumetanide or RU486 showed therapeutic efficacy.

Animals

Long-Term Warming Reduces Bacterial Diversity and Functional Potential in Temperate Forest Soil.

Soil microbes are key regulators of forest carbon cycling, yet how their diversity and functional potential respond to long-term warming remains poorly understood. Here, we report a five-year in&#xa0;situ warming experiment in a temperate forest, combining ten repeated measurements of microbial diversity and functional gene potential, as well as continuous monitoring of soil CO2 flux. We found that warming progressively reduced bacterial diversity and induced phylogenetically conserved community reorganization. Under warming, community composition shifted in a phylogenetically conserved manner. Warming generally reduced the abundance of microbial functional genes across most carbon-, nitrogen-, and phosphorus-cycling gene categories, except for genes associated with starch decomposition. Warming also altered the factors associated with soil CO2 flux: microbial diversity showed a stronger association with soil CO2 flux under long-term warming, whereas soil moisture was the dominant predictor in the control treatment. This warming-enhanced biodiversity control over soil CO2 flux was associated with shifts in microbial functional potential, particularly increases in starch-degrading genes and microbial biomass production potential. Together, our results suggest that warming can restructure microbial communities in ways that strengthen biodiversity-dependent regulation of soil carbon cycling, with implications for climate-carbon feedbacks.

Soil Microbiology

Effects of Fecal Microbiota Transplantation on Intestinal Microbial Characteristics and Clinical Phenotypes in Patients with Parkinson's Disease.

Alterations in the gut microbiota have been associated with Parkinson's disease (PD), but longitudinal microbial changes after fecal microbiota transplantation (FMT) and their clinical associations remain poorly understood. This single-center retrospective observational study included 6 patients with PD, stratified into high- and low-severity subgroups based on disease duration (>6 years vs &#x2264;6 years). Thirty-six fecal samples were collected before FMT and monthly for five months afterward. Microbial diversity, community structure, taxonomic composition, and predicted functional profiles were assessed using 16S ribosomal RNA gene sequencing. Analyses included alpha and beta diversity, taxonomic abundance, linear discriminant analysis effect size, Tax4Fun2-based functional prediction, and Spearman rank correlations between microbial features and clinical indicators. Descriptive analyses indicated differences in microbial richness, diversity, community structure, and predicted functions between severity subgroups and across post-FMT time points. At baseline, the low-severity subgroup had greater microbial richness and diversity than the high-severity subgroup, with relatively higher abundances of taxa including Bifidobacterium and Lactobacillus. One month after FMT, richness and diversity increased from baseline in the high-severity subgroup, accompanied by changes in taxonomic composition. Both subgroups showed time-associated variation in microbial diversity and predicted Kyoto Encyclopedia of Genes and Genomes pathway enrichment after FMT. Predicted functions included carbohydrate and amino acid metabolism, secondary metabolite biosynthesis, membrane transport, and signal transduction. Several operational taxonomic units correlated with indicators of motor impairment, constipation, sleep quality, functional status, and neuropsychiatric symptoms. FMT was therefore associated with longitudinal changes in gut microbial diversity, composition, and predicted functions, and specific microbial features were associated with motor and non-motor indicators. Given the small retrospective cohort, these findings are preliminary and warrant confirmation in larger controlled studies. Future studies should determine whether these microbial alterations are reproducible, persist beyond five months, reflect donor engraftment, and correspond to measurable clinical improvement after transplantation in PD.

Humans

Microbial decomposer diversity and metabolic function during the decomposition of brine shrimp carcasses in a saline lake.

BACKGROUND: Decomposition of brine shrimp carcasses has a crucial role in carbon cycling of saline lakes, yet the microbial dynamics remain poorly understood. RESULTS: Here we integrated metagenomics, metatranscriptomics, culturomics, metabolomics, and microcosm experiments to investigate microbial community succession and function during brine shrimp (Artemia sp.) carcass decomposition in Barkol Lake, a hypersaline lake in China. A total of 149 metagenome-assembled genomes (MAGs) and 77 pure culture genomes were recovered across 33 phyla, with 72.12% genomes representing species-level novel lineages. Our results reveal diverse bacterial and archaeal taxa, including novel lineages from CG03, T1Sed10-126 and rare archaeal taxa (Asgardarchaeota, Thermoplasmatota, Nanoarchaeota, and Halobacteriota), involved in degradation of biomacromolecules-proteins, carbohydrates, lipids, and nucleic acids-via extracellular hydrolysis, nutrient transport, and intracellular catabolism. These taxa exhibit substrate preferences, rapidly responding to the breakdown of polysaccharides and proteins, followed by lipids and nucleic acids. Hydrolyzed oligomers are further oxidized by various microbes through fermentation, sulfate reduction, and methanogenesis via metabolic handoffs. Additionally, viral auxiliary metabolic genes (AMGs) further enhance microbial host functions, contributing to key ecological processes such as carbon cycling and stress response. A temporally structured microbial decomposer network (MDN) was observed, driving mineralization cascades from fermentation to sulfate reduction and methanogenesis. CONCLUSIONS: This study reveals microbial metabolic handoffs and virus-mediated modulation as critical mechanisms for organic matter turnover, expanding the known diversity and function of decomposers in saline ecosystems. Our findings offer new insights into biogeochemical processes in saline lakes and highlight a synergistic microbial decomposer network involving bacteria, archaea, and viruses that collectively drive nutrient cycling during brine shrimp carcass decomposition. Video Abstract.

Animals

Isoquinoline alkaloids enhance growth performance through multifaceted modulation of the bacterial-fungal microbiome, CAZyme profiles, gut health, and neuroendocrine function in broilers.

The bacterial-fungal microbiome and its carbohydrate-active enzyme (CAZyme) capacity play critical roles in regulating gut health and growth performance in broiler chickens. This study evaluated the effects of dietary isoquinoline alkaloids (IQ) on growth performance, gut microbiome composition, CAZyme profiles, and the microbiome-gut-neuroendocrine axis in broilers. A total of 400 Ross 308 (1-day-old) chicks were randomly assigned to either a Basal diet (CON) or IQ supplemented diet (IQ). Dietary IQ supplementation significantly increased final body weight and cumulative body weight gain (P < 0.0001) and improved feed conversion ratio (P < 0.05). Intestinal permeability was reduced (lower FITC-dextran; P < 0.05), accompanied by increased serotonin and serotonin-to-corticosterone ratio and decreased corticosterone (P < 0.05). Expression of inflammatory genes (TNF-&#x3b1;, NF-&#x3ba;B, IL-4, and TLR-1) was downregulated (P < 0.05). Microbiome analysis showed increased &#x3b1;-diversity (P < 0.05) and clear &#x3b2;-diversity separation (PERMANOVA, P < 0.001), with enrichment of beneficial bacteria (Akkermansia muciniphila, Lactobacillus salivarius, Turicibacter sanguinis, Bacillus subtilis) and suppression of fungal taxa (Aspergillus, Penicillium). CAZyme-related pathways involved in lignin and carbohydrate degradation were increased (P < 0.05). Microbial diversity was negatively correlated with inflammation and gut permeability, whereas network analysis identified 164 significant associations (|&#x3c1;| &#x2265; 0.50), revealing strong negative correlations between beneficial bacteria and inflammatory markers (&#x3c1; = -0.65 to -0.78) and positive associations for fungal taxa (&#x3c1; = 0.62-0.81). Serotonin was positively associated with microbial diversity (&#x3c1; = 0.63-0.70). In conclusion, IQ supplementation promotes a bacteria-dominant and metabolically active microbiome, reduces inflammation and intestinal permeability, and improves neuroendocrine balance, collectively enhancing gut health and growth performance in broiler chickens.

Bacteriome

Metagenomics Reveals Microbial Community Shifts Associated With Contrasting Anthropogenic Impacts in Freshwater Sources of A Coastal Protected Area in Southeastern Brazil.

This study aimed to characterize freshwater microbial communities, environmental drivers, and anthropogenic impact patterns across three sites on Marambaia Island (southeastern Brazil) using metagenomics. Samples collected from freshwater sources used for human consumption were processed through concentration, nucleic acid extraction, and sequencing on the Illumina NextSeq 2000 platform. A total of 67.2 million reads were assembled into 89,230 bacterial contigs, mostly attributed to Gammaproteobacteria, Alphaproteobacteria, and Betaproteobacteria. Sites under lower anthropogenic influence exhibited higher microbial diversity, whereas impacted sites showed enrichment of opportunistic and fecal-associated genera. A heterogeneous anthropogenic impact profile was observed across sites, corroborated by the proposed Anthropogenic Impact Index (AII). Fourteen antimicrobial resistance genes conferring resistance to beta-lactams, quinolones, sulfonamides, tetracyclines, and macrolides were detected predominantly in sewage-impacted areas, indicating potential diffuse contamination. Redundancy analysis revealed that environmental variables explained 88.1% of microbial community variation, with conductivity, salinity, and turbidity as key drivers. These findings demonstrate the applicability of metagenomics as a powerful tool for assessing microbial diversity, ecological dynamics, and contamination risks in vulnerable freshwater systems.

Brazil

Integrative machine learning models to unravel gut microbial dysbiosis and functional disruption in polycystic ovary syndrome.

OBJECTIVE: To study gut microbial diversity and metabolic pathway disruptions in women with PolyCystic Ovary Syndrome (PCOS) compared with healthy controls, and to evaluate the diagnostic potential of microbiome-driven machine learning models. DESIGN: Case-controlled metagenomic data analysis SUBJECTS: Gut metagenomic data from women diagnosed with PCOS and age-matched healthy female controls EXPOSURE: Presence of PCOS MAIN OUTCOME MEASURES: The primary outcome measures will include gut microbial alpha and beta diversity indices, microbial taxon abundance, functional pathway profiles, predicted metabolite levels, microbe-functional pathway-metabolite interaction networks, and the diagnostic accuracy of microbiome-based machine learning models. RESULTS: Alpha and beta diversity analyses revealed marked gut microbial dysbiosis in women with PCOS, despite comparable species richness to healthy controls. Differential abundance analysis identified 41 significantly altered microbial species, including enrichment of proinflammatory taxa, such as Bacteroides vulgatus and Ruminococcus gnavus, and depletion of beneficial commensals, including Roseburia hominis and Prevotella copri. These compositional shifts indicate a proinflammatory microbial community structure in PCOS. Functional profiling demonstrated the upregulation of pathways involved in nucleotide turnover, lipid and carbohydrate metabolism, and neurotransmitter synthesis, potentially contributing to metabolic and neuroendocrine disruption. Network analysis revealed fragmented and unstable microbial-metabolite associations in PCOS compared with cohesive networks in controls. Microbiome-based machine learning models achieved a diagnostic accuracy of 84.25% (area under the curve 0.93), underscoring their predictive potential. CONCLUSION: The gut microbiome in PCOS is characterized by a proinflammatory community structure and disrupted metabolic pathways. These findings demonstrate the diagnostic potential of microbiome-based models and underscore the gut microbiome as a promising target for therapeutic interventions in the management of PCOS.

Polycystic Ovary Syndrome