Tilapia (Oreochromis spp.) are among the most widely cultivated freshwater finfish species worldwide. The industry increasingly relies on tilapia strains selected for improved growth and other traits, particularly the Genetically Improved Farmed Tilapia (GIFT) strain. Despite the industry's reliance on tilapia, knowledge of microbiome dynamics in reared tilapia remains limited. Understanding normal successional patterns in the microbiome of farmed tilapia is essential for identifying the characteristics that constitute a healthy microbial community. In this study, we assessed the microbiomes of tank and pond-reared GIFT tilapia by analyzing 568 samples, including water, gut, skin, and gill microbiomes of tilapia, from tank systems housing the source GIFT populations in Malaysia. We compared them to those reared in earthen ponds on another farm in Malaysia. A total of 2,307 amplicon sequence variants (ASVs) were identified, encompassing a broad taxonomic diversity of 39 phyla, 86 classes, 180 orders, 299 families, 501 genera, and 399 species. Our findings elucidated distinct microbial community structures between rearing environments and across fish tissues, shedding light on intricate host-microbe interactions shaped by environmental conditions and management practices. The gut microbiome of tank-reared tilapia was dominated by Fusobacteriota (71.14%), in contrast to pond-reared fish (22%). At the same time, other taxa, such as Bacteroidota, Firmicutes_A, and Cyanobacteria, also varied markedly between environments and sampling periods. Skin and gill samples exhibited notable variability in the relative abundances of Fusobacteriota and Deinococcota between the two rearing sites. Principal Coordinates Analysis (PCoA) highlighted the distinct clustering of samples by rearing environment, particularly within gut microbiomes. Biomarkers such as Cyanobiaceae (pond water) and Sphingomonadaceae (tank water) underscored the impact of rearing conditions on microbial composition. These results establish valuable baseline information on the types of bacteria associated with healthy, genetically defined (GIFT) tilapia strains. This foundational information will help identify specific microbial taxa associated with beneficial or detrimental effects on tilapia health and productivity across varying rearing conditions. Such insights can guide the development of practical microbiome monitoring strategies, such as early-warning tools for farm health, and inform targeted interventions to improve aquaculture performance.
The gut microbiome influences cardiovascular health through metabolite production and immune modulation. Gut microbial dynamics and cardiovascular outcomes are also shaped by biological sex. However, sex-specific responses to myocardial infarction (MI) that involve the gut microbiome and intestinal milieu remain poorly defined, particularly in older hosts. Here, we characterize gut microbiome structure and function alongside physiological and immune responses to MI across multiple tissues in aging male and female mice. MI was induced by permanent LAD ligation and confirmed by echocardiography in C57BL/6N retired breeder mice. Sham surgery (SH) and no surgery (NoSx) groups served as controls. Gut microbiota and the cecal metabolome were characterized using 16S rRNA sequencing and untargeted UPLC-MS, respectively. Immune cells in the small intestine, heart, bone marrow, and spleen were quantified by flow cytometry, and small intestinal morphology was assessed on H&E-stained sections. Sex-specific differences were evident at baseline. Following MI, pronounced time- and sex-specific differences in gut microbial and immune cell populations were observed, peaking on day 3 (D3) and absent in SH and NoSx controls. Early increases in Bacteroidaceae, Tannerellaceae, and Marinifilaceae were present in both sexes, with sex-specific enrichment of Bacteroidaceae in males and Akkermansiaceae in females. Metabolomic analyses identified increased secondary bile acid derivatives, including cholylvaline in males and 12-oxo-lithocholic acid in females. Integration of microbiota-metabolome data revealed MI-responsive and homeostatic taxa with opposing metabolite signatures, while functional analyses indicated enrichment of propanoate and amino acid metabolism pathways. These changes were temporally aligned with acute MI-induced expansion of intestinal MHCII+CD11c+ dendritic cells and TCRαβ+CD4+, TCRαβ+CD8αβ+, and CD25+FoxP3+ regulatory T cells on D3 in both sexes. Males alone exhibited marked increases in intestinal TCRγδ+ T cells, while females showed increased accumulation of innate immune cells. Convergence of peak physiological, immunological, and microbial responses on day 3 after MI reveals coordinated responses across the gut-heart axis that are fundamentally influenced by sex. Our findings highlight the need for personalized, sex-specific perioperative strategies and identify the gut microbiome as a potential therapeutic target to improve outcomes after MI.
Non-Western diets are increasingly studied for their relationship to gut microbiota composition and diversity, although most research in this area has focused on plant-based, fiber-rich diets. Here, we present a single-participant longitudinal study investigating gut microbiota dynamics during a transition from a Western diet to a 12-week Indigenous Arctic animal-based diet composed of minimally processed raw, dried, and fermented animal-source foods. During one month of this period, the participant consumed dried whole fish (ammassak), including intestinal contents, representing a form of gastrophagy, a practice common to the Arctic diet, that may increase exposure to food-associated microbes. Fecal samples (n = 29) were collected before, during, and after the Arctic diet phase. 16S rRNA gene sequencing of the V3-V4 region was used to profile bacterial communities. Diversity metrics, Firmicutes/Bacteroidota (F/B) ratios, and taxonomic composition analyses were performed to assess compositional shifts across diet phases. Alpha diversity remained relatively steady throughout the study, with a tendency toward higher values during the Arctic diet. The F/B ratio increased from 1.31 to 2.12 during the Arctic diet phase and remained elevated (2.38) after returning to a Western diet. Beta diversity analysis revealed significant restructuring of the gut microbiota at the onset of the Arctic diet, followed by partial reversibility upon returning to a Western diet. Fiber-associated taxa like Prevotella 9 disappeared, and Bifidobacterium declined, while protein- and fat-associated taxa, including Bacteroides, Lachnoclostridium, and Alistipes, increased. Several genera appeared during the Arctic diet phase that were absent during the preceding Western diet phase, consistent with altered microbial exposure. Among those, Photobacterium was also detected in the ammassak, suggesting potential microbial exposure during the gastrophagy period. These results provide preliminary evidence that the gut microbiota can shift substantially during an Indigenous Arctic dietary transition. Because the Arctic diet also substantially overlapped with sustained high physical activity, the observed changes should be interpreted in the context of a combined dietary and lifestyle transition. These findings highlight the need for a better understanding of underrepresented dietary patterns, such as those of Arctic Indigenous communities, and their relationship with the gut microbiota.
The human milk microbiota significantly contributes to the shaping of the infant gut microbiota during early life. Influenced by maternal factors such as birth mode, diet, and breastfeeding practices, these microbial communities are critical for infant health. We explored the effect of maternal human immunodeficiency virus (HIV) status and breastfeeding practices on breast milk microbiota composition and its correlation with infant gut microbiota between 7 and 14 days postpartum. Breast milk and stool microbiota from 68 lactating HIV-infected and uninfected women and their 69 infants (including one set of twins) were characterized using 16S rRNA gene sequencing. Sociodemographic and clinical data were also collected. Breast milk microbiota was dominated by Streptococcus and Gemella, whereas the infant gut microbiota showed a co-occurrence of early colonizers such as Enterobacteriaceae_unclassified, Bifidobacterium, and Streptococcus. In contrast, maternal stool exhibited greater microbial diversity, enriched in Romboutsia and Clostridium_sensu_stricto_1. Small, non-significant differences were observed in alpha diversity by maternal HIV status (Cohen's d ≈ -0.38; 95% CI: -3.88 to 0.07), suggesting possible modest to no effects, even though p-values were not significant. Clostridium_sensu_stricto_1 was more abundant in HIV-uninfected mothers. Infant HIV exposure and maternal antibiotic prophylaxis had no detectable effect on gut microbiota diversity or composition. Notably, positive correlations were observed between breast milk and infant gut taxa abundances, including Gemella (ρ = 0.33, p = 0.010) and Enterobacteriaceae_unclassified (ρ = 0.31, p = 0.016). SourceTracker analysis indicated that 31.5% of infant gut taxa were traceable to breast milk, with higher contributions in HIV-exposed infants (41%) compared with HIV-unexposed infants (25.6%). This study is among the first to investigate breast milk microbiota in the context of HIV infection in Zimbabwe. We demonstrated that maternal HIV infection and cotrimoxazole prophylaxis did not measurably alter breast milk or early infant gut microbiota composition. Despite limited statistical power to detect small-to-moderate effects, taxa-level correlations and microbial source tracking supported breast milk as a major contributor to early gut colonization. These results underscore breast milk-mediated microbial seeding in early life, while highlighting the need for larger longitudinal studies to define how maternal HIV status may subtly influence vertical microbial transfer.
Alzheimer's disease (AD) is one of the most diagnosed neurodegenerative disorders worldwide and presents a significant challenge for both affected individuals and their caregivers. Alzheimer's disease is characterized by the accumulation of amyloid plaques and dysfunctional tau protein in the brain, along with the final development of dementia. Recently, in addition to the strongly developing ischemic etiology of AD, it is suggested that the gut and oral microbiota may also participate in the development of this disease. This involvement may stem from an unbalanced diet and the consumption of foods containing harmful chemical additives. An unhealthy diet can compromise the integrity of the gut barrier, facilitating the translocation of bacterial pathogens and leading to a pro-inflammatory T-cell response mediated by innate immune cells. This inflammatory response can disrupt systemic homeostasis and may contribute to neuroinflammation. The brain and gut interact through a complex network known as the "gut-brain-microbiota axis," and emerging studies suggest that the intestinal microbiota and their metabolites may play a significant role in the pathogenesis of Alzheimer's disease. Moreover, these inflammatory mediators and microbial metabolites can reach the brain via the gut-brain axis, potentially exacerbating neurodegenerative processes. Preclinical and limited clinical evidence indicates that low-fiber diets are associated with alterations in intestinal microbiota composition, which may contribute to the onset and progression of Alzheimer's disease. This review aims to explore the potential connections between AD and the gut microbiome, emphasizing the significance of dietary factors in shaping these relationships. A comprehensive understanding of the interactions between the human microbiome and the brain, particularly in the context of diet and its ingredients, may enhance our understanding of AD etiology and inform the development of preventative strategies, through dietary modifications or therapeutic interventions. This area of research holds promise for identifying novel approaches to prevent or slow the progression of AD.
Endophytic bacteria contribute to plant growth, stress tolerance, and pathogen resistance. Their effective use in agriculture requires the identification of strains that combine multiple beneficial traits with consistent performance across different field conditions. Accordingly, this study examines Bacillus and Pseudomonas endophytes isolated from Cannabis sativa L. and Chelidonium majus L. for plant growth promotion, abiotic stress tolerance, and biocontrol properties. Plant growth-promotion traits included indole, siderophore, and organic acid production, phosphate and zinc solubilization, and biofilm formation. Results showed that all the tested bacterial isolates produced indoles, with the highest levels recorded in Pseudomonas strain PPW-26, whereas several Pseudomonas strains exhibited strong siderophore production. Strain PPW-26 tested positive for methyl-red, indicating organic acid production, whereas other Pseudomonas strains tested negative. Moderate to high nutrient solubilization profiles were observed across all Pseudomonas strains. Bacillus strains, particularly BS-114, exhibited higher biofilm formation relative to Pseudomonas. Assessment of abiotic stress tolerance included proline accumulation, superoxide dismutase activity, and growth under varying temperature, salinity, and drought conditions. All strains displayed tolerance to the tested stresses, with Bacillus strains showing stronger resilience to high temperature and salinity, accompanied by elevated proline accumulation and superoxide dismutase activity in selected strains. Biocontrol potential was evaluated through biosurfactant production and antifungal activity. Bacillus strains showed high biosurfactant activity and strong inhibition of fungal pathogens. Strain BS-120 exhibited broad-spectrum inhibition against Fusarium oxysporum, Fusarium graminearum, and Rhizoctonia solani-AG3. Analysis of genome sequences identified biosynthetic gene clusters encoding antifungal metabolites, including fengycin and surfactin, consistent with the observed inhibition. Genome-wide similarity analysis and ANI-based clustering revealed the presence of highly similar and genetically distant strains within each genus. For Bacillus spp., ANI values ranged from 87.62% to 98.83%, whereas for Pseudomonas spp. they ranged between 83.91% and 99.99%, confirming the presence of substantial intra-genus diversity. Phylogenetic analysis showed well-supported clades consistent with ANI clustering. Overall, this study demonstrates that endophytic Bacillus and Pseudomonas strains exhibit complementary and strain-dependent traits associated with plant growth promotion, stress tolerance, and pathogen suppression, supporting their further evaluation as potential bioinoculants for sustainable agriculture.
As climate change increases global water temperatures, ecologists expect intestinal helminth infection ranges to expand and increase the health burden on aquatic organisms. However, the gut microbiome can interact with these parasites to influence infection outcomes, raising the possibility that its response to increasing temperatures may help buffer against increased infection burden or worsen infection outcomes (e.g., inflammatory bowel disease). To evaluate this hypothesis, we sought to determine if the microbiome is resistant or resilient to the stressors of increased water temperature, helminth exposure, and their combination, and whether this variation linked to infection outcomes. We leveraged the zebrafish (Danio rerio) model organism to measure how these variables relate to the temporal dynamics of the gut microbiome. In particular, we exposed adult zebrafish to Pseudocapillaria tomentosa, parasitic capillarid with a direct life cycle, across three different water temperatures (28°C, 32°C, 35°C), and analyzed fecal microbiome samples at five time points across 42 days. Our findings show that parasite exposure and water temperature independently alter gut-microbiome diversity. Moreover, water temperature moderates the association between parasite infection and the gut microbiome. Consistent with this observation, yet counter to prevailing expectations, we find that increasing water temperature reduces P. tomentosa infection worm development and overall abundance in zebrafish. The decline in worm burden at 35°C may be due to either direct thermal inhibition of P. tomentosa development or temperature-mediated interactions with the host microbiome and immune response. Overall, our results indicate that water temperature alters the contextual landscape of the gut microbiome and shapes its response to an intestinal parasite in zebrafish. To our knowledge, this represents the first report of elevated temperature constraining nematode development in a fish host, underscoring that climate change may impose unanticipated, context-dependent impacts on vertebrate gut microbiomes and health outcomes.
Soil microbiome research has been revolutionized by advances in high-throughput sequencing and multi-omics technologies, generating massive datasets that capture the taxonomic, functional, and metabolic diversity of microbial communities in agricultural soils; however, interpreting these complex datasets and translating them into practical agronomic insights remains challenging. To critically assess the role of artificial intelligence (AI) in soil microbiome-driven agriculture, focusing on methodological developments, prediction performance, existing limitations, and translational opportunities. A narrative review was conducted to evaluate commonly used AI approaches, including random forest, gradient boosting, support vector machines, and deep learning architectures, alongside key microbiome data types such as amplicon sequencing, metagenomics, and functional gene profiling, with integration of environmental, agronomic, and meteorological datasets. The prediction of crop productivity, disease risk, nutrient cycling dynamics, and soil health indicators may be enhanced by AI-assisted integration of microbiome, soil physicochemical, and meteorological data, according to several studies. However, broad generalizations about predictive robustness and generalizability are limited by significant diversity in datasets, validation methods, and model architectures. To address these limitations, a five-phase implementation framework integrating centralized data systems, AI-driven analytics, multi-omics profiling, standardized soil sampling, and feedback-based model retraining within precision agriculture systems is proposed, providing a pathway for translating microbiome insights into field-scale decision support. AI-enabled soil microbiome applications hold significant potential for sustainable agriculture, but future advancements will require large, multisite datasets, improved validation strategies, interpretable modeling approaches, and integration with digital agriculture technologies, highlighting both opportunities and practical constraints.
The gut microbiota and bile acids (BAs) exist in a tightly regulated, bidirectional relationship that influences host metabolism, immune function, and disease. Primary BAs synthesized in the liver are chemically transformed by intestinal microbes into a diverse pool of secondary BAs, which exert antimicrobial effects and activate host signaling pathways including Farnesoid X Receptor (FXR), Takeda G protein-coupled receptor 5 (TGR5), and sphingosine-1-phosphate receptor 2 (S1PR2). These pathways regulate BA homeostasis, epithelial barrier integrity, inflammation, and carcinogenesis. Disruption of this BA-microbiome axis has been implicated in biliary tract cancers (BTCs), a group of aggressive malignancies with rising global incidence and limited therapeutic options. Secondary BAs and BA receptor signaling contribute to tumor initiation and progression through NF-κB activation, oxidative stress, and altered cell survival, whereas reduced FXR signaling and obstructed enterohepatic circulation further promote inflammatory dysregulation. Emerging evidence demonstrates that microbial dysbiosis and altered BA metabolism are associated with distinct BTC microbial profiles, enriched in taxa such as Fusobacterium, Salmonella, Prevotella, and Actinomyces, alongside depletion of commensals including Lactobacillus. These taxa influence inflammatory signaling, BA transformation, and epithelial injury, contributing to carcinogenesis. Microbiome-BA interactions also shape anti-tumor immunity and responses to immune checkpoint inhibitors (ICIs). Specific microbial signatures-particularly enrichment of Lachnospiraceae, Erysipelotrichaceae, Bacteroidetes, and Alistipes-correlate with enhanced immune activation and improved clinical outcomes in hepatobiliary cancers. Modulation of gut microbiota through antibiotics, probiotics, or fecal microbiota transplantation can influence BA composition, immune surveillance, and therapeutic efficacy. Collectively, these data highlight the central role of the BA-microbiome axis in BTC pathogenesis and treatment response. Microbial and BA metabolite profiling represent promising avenues for biomarker development, while targeted manipulation of BA signaling and microbial ecology offers potential therapeutic strategies to improve BTC outcomes.
The human gut microbiome represents a complex and dynamic therapeutic target whose effective interrogation requires system-level analytical approaches beyond single-omics or reductive methods. This mini-review synthesizes recent advances in computational modeling and multi-omics integration relevant to the development of predictive, patient-tailored microbiome therapies. We critically assess the analytical strengths and limitations of genome-scale metabolic models (GEMs); generalized Lotka-Volterra and ODE-based community models; agent-based simulations; and statistical machine-learning frameworks and examine how their integration with metagenomics, metatranscriptomics, metaproteomics, and metabolomics can help bridge microbial functional potential with clinically relevant phenotypes. Representative applications-including MintTea for disease module identification, gNOMO2 for integrative microbiome profiling, and AGORA-based community metabolic modeling-illustrate the translational scope of these frameworks across inflammatory, metabolic, and infectious disease contexts. Hybrid ML-GEM frameworks have not yet been directly applied to FMT outcome prediction; however, the mechanistic principles underlying both approaches - metabolic compatibility modeling and data-driven responder stratification - suggest a compelling direction for future investigation, contingent on prospective validation in adequately powered and independent clinical cohorts. Persistent methodological challenges-such as data heterogeneity, batch effects across sequencing platforms, incomplete multi-omics coverage, and limited interpretability of complex machine-learning models-are being actively addressed through standardized preprocessing pipelines, explainable Artificial intelligence (AI) strategies, and federated analytics. While federated approaches enable privacy-preserving, multi-institutional model training, they introduce additional constraints related to non-identically distributed data, communication overhead, and uneven computational capacity. Overall, the convergence of mechanistic modeling, data-driven learning, and distributed analytical infrastructures may assist in advancing microbiome research from a largely correlational perspective toward mechanistic and ultimately prescriptive frameworks for precision microbiome medicine.
Although microbial community compositions vary throughout the healthy human body, some taxa can be found to reside in multiple anatomical sites. Moreover, some microbiota that have been found to be interconnected, e.g., the gastrointestinal tract and the oral cavity, the female urinary tract and the vagina, the nose (specifically the nares) and the skin. Previously, the urinary microbiome has only been compared to proximal sites; however, several species that inhabit the asymptomatic female urinary tract are also found in distant communities, e.g., Streptococcus mitis, also found in the oral cavity, and Staphylococcus epidermidis, also found in the nares. This prompted our investigation of communities of the oral cavity, nares, and urinary tract, collected from the same individual. In this study, we profiled the oral, nasal, and urinary microbiomes of 26 self-identified "healthy" female participants using 16S rRNA amplicon sequencing. The urinary microbiome was found to be distinct from the oral and nasal communities. Nevertheless, Actinomyces, Corynebacterium, Escherichia + Shigella, Lawsonella, Staphylococcus, and Streptococcus were found to be present within communities of all three anatomical sites. Genera predominant within the oral and nasal communities were often low-abundant taxa within the urinary microbiome. To date, comparisons of the urinary microbiome to microbiomes of other anatomical sites is limited. The distinction between the urinary microbiome and that of the more distant oral and nasal site highlights the role that the environment plays in shaping these communities.
Ocean Alkalinity Enhancement (OAE) is a proposed marine carbon dioxide removal strategy that increases seawater buffering capacity and CO2 uptake through the addition of alkaline substances. While OAE shows promise as a climate mitigation tool, its ecological implications remain poorly understood, particularly regarding microbial communities. This paper provides a risk assessment of two different OAE strategies: alkalization with olivine and alkalization with addition of dissolved sodium hydroxide (NaOH). With a mesocosm experiment designed to simulate coastal OAE application, European flat oysters (Ostrea edulis) were chronically exposed to alkalinity-enhanced seawater at two concentrations (250 and 500 µmol·L-¹) derived either from olivine weathering or addition with NaOH. The bacterial community composition of both alkalization types was assessed with amplicon sequencing of the 16S rRNA gene and ecotoxicological impacts were compared to a non-alkalized control. The sampling strategy included samples of the treated waters and the gill microbiome of Ostrea edulis. Our results show that the alkalization type was the primary driver of microbial shifts in the bacterial community of the water samples. Olivine treatments caused distinct taxonomic changes, including an increase in Gammaproteobacteria and Flavobacteriales and a marked decline in Alphaproteobacteria and SAR11 clade. Olivine-treated waters showed reduced richness and evenness. In contrast, dissolved alkalinity treatments produced minimal changes compared to untreated controls. The analysis of the oyster gill microbiome detected a response that was stronger influenced by alkalinity concentration than by alkalization type. Notably, high-alkalinity olivine treatments favored potentially pathogenic Vibrios. Together, these findings highlight that OAE method selection significantly influences bacterial community composition in both marine and host-associated microbiomes. In our experiment, olivine-based OAE posed a greater environmental risk than dissolved OAE. Our study provides insights on the impact of different OAE scenarios, representing a first step toward future field trials and applications.
Integrating perennial forage seed crops into annual cropping sequences can diversify the rotations and improve soil health, yet their effects on the soil microbial communities and functions are not yet fully elucidated on the Canadian prairies. Using a 10-year field experiment with eight cropping sequences under varying supplemental nitrogen (N) fertilization levels, we evaluated the impacts of integrating perennial seed crops and annual crops on soil microbial biomass carbon (MBC), the composition and diversity of prokaryotic and fungal communities, and the activities of key enzymes involved in carbon (C), N, phosphorus (P), and sulfur (S) cycling, namely β-glucosidase, N-acetyl-β-glucosaminidase, acid phosphomonoesterase and arylsulfatase. The crop sequences containing intermittent succession of perennial and annual crops had 17% greater soil MBC, higher fungal richness (e.g., Chao1 indices of 92.8 vs. 87.6) and 22% greater β-glucosidase activity than annual-only sequences. The relative abundances of the two most abundant prokaryotic phyla - Actinobacteriota and Proteobacteria - as well as the second most abundant fungal class, Dothideomycetes, followed the same trend. The soils with more frequent recurrence of grassy perennials in the sequences exhibited greater MBC (34%), higher prokaryotic Shannon diversity, greater fungal richness, and higher arylsulfatase activity (68%) than soils with more frequent recurrence of perennial legumes, although the predominant prokaryotic phylum, Actinobacteriota was more abundant in legume-based systems. The cropping sequences dominated by creeping red fescue grass seed crops exhibited the greatest improvement in most of the soil microbial metrics studied. Nitrogen fertilizer increased the relative abundance of the copiotrophic Actinobacteriota but decreased that of the oligotrophic Acidobacteriota. Prokaryotes were associated with C, N, P and S cycling, whereas fungi were primarily linked to C cycling. Overall, diversifying annual grain cropping systems with perennial forage seed crops, particularly creeping red fescue, enhanced key indicators of biological soil health.
Humans have used wood as a construction material throughout history. Currently, mass timber products, such as cross-laminated timber (CLT), are becoming more popular as a structural material, since they are renewable and have a lower carbon footprint than concrete or steel. Nonetheless, some building types, such as healthcare, veterinary, and food manufacturing, avoid using structural mass timber due to concerns about microbial growth in the event of wetting. One solution is to use protective coatings on mass timber products to increase moisture resistance, although the coatings themselves may generate concerns about volatile organic compound (VOC) emissions. Natural uncoated wood also produces VOCs, some of which may have intrinsic antimicrobial effects. In this study, we inoculated coated and uncoated cross- laminated timber (CLT) blocks with a mock microbial community and isolated each block within individual sealed microcosms. We characterized VOCs and surface microbial communities from the CLT blocks before, during, and after wetting periods of varying durations. VOC concentration and emission rate were analyzed with chromatography-mass spectrometry (GC-MS), while microbial community abundance, diversity, and composition were analyzed through qPCR and shotgun metagenomics. VOC emissions were elevated immediately after inoculation, then decreased through the remainder of the experiment, except for a plateau during the wetting period. VOCs from uncoated CLT blocks were primarily terpenes, while coated blocks emitted VOCs associated with coatings, plastics, and industrial solvents, as well as terpenes. One VOC-acetoin (3-hydroxy, 2-butanone)-was present at high levels across all samples immediately after microbial inoculation. Bacteria comprised 99.54% of the identified microbial sequences. The plastic control microcosm (not containing a CLT block) had higher abundance of viable bacteria for the majority of the study, but there was no difference in abundance between coated and uncoated blocks. Prior to wetting periods, microbial composition was driven primarily by sampling day, whereas surface type played a larger role during and after wetting periods.
Whether domestication, post-domestication spread, and breeding affected the maize leaf endosphere microbiota is poorly understood despite the well-known effects of those processes on the crop's genetics and responses to the environment. We examined the leaf endosphere microbial communities associated with three plant groups (Zea mays): teosintes, maize landraces, and maize elite inbreds. The teosintes group included Balsas (Z. mays parviglumis) and perennial (Zea diploperennis) teosinte, and each maize (Z. mays mays) group included genotypes from Mexico and USA. We used 16S-V4 region amplicon sequencing of the leaf endophytic microbiota to infer how the microbial communities of inbred maize may have been shaped by the crop's evolution, and whether they were affected by: (i) the transition from a perennial life history to an annual life history in the teosintes; (ii) domestication of maize from Balsas teosinte; (iii) northward spread of landrace maize from Mexico to the US; and (iii) breeding of landrace maizes to produce elite inbreds. The leaf endophytic microbial community differed among the plant groups and genotypes, and was affected by domestication, as indicated by a decline in bacterial diversity and changes in microbial community structure between wild (teosinte) and domesticated (maize) Zea. While the microbial community structure was stringent and regulated in the teosintes, it was variable in the maize landraces and inbreds, as evidenced by greater distances to centroid based on Euclidean dissimilarity metric. This pattern was suggestive of microbial dysbiosis in the leaf endosphere associated with domestication and is consistent with predictions of the Anna Karenina principle. This finding marks the first evidence of dysbiosis associated with domestication. FAPROTAX predictions suggested that the teosintes may harbor microbial communities enriched in taxa associated with cellulolytic, chitinolytic, and nitrate respiration functions, while the maizes showed higher fermentation and nitrate reduction functions. Our results showed that the leaf endosphere microbial community structures in maize are consistent with alterations associated with dysbiosis. Our findings enhanced our understanding of the effects of anthropogenic processes including crop domestication, spread, and breeding on the leaf endosphere of elite maize cultivars, and may guide the development of evolutionarily-and ecologically sustainable biofertilizers and biocontrol agents.
The function of the respiratory microbiome during an active infection is not well characterized. Studies from the gut microbiome suggest a diverse community can aid in modulating the immune system to control infectious pathogens. To determine if there are microbial community compositional changes in the human lung during an infection, we conducted an analysis of both the 16S rDNA and the Internal Transcribed Spacer (ITS) region of DNA from bronchoalveolar lavage fluid (BALF) of patients from Mayo Clinic Arizona. In addition to general classification, we assessed differences in the lung microbiome of patients with different infections including coccidioidomycosis, a common fungal pneumonia in Arizona. We observed patterns of dysbiosis in the lung microbiome during active fungal infection. Patients with active coccidioidomycosis infections had an overabundance of Malassezia, Epicoccum, and Penicillium species in the fungal communities and bacteria in the classes Bacilli, Bacteroidia, Clostridia, and Gammaproteobacteria. Patients with disseminated coccidioidomycosis showed evidence of extreme dysbiosis in the lung microbiome with a significant overabundance of Malassezia and Bacilli. We also observed differences in the fungal communities of patients with an active Candida albicans infection, with an overabundance of the genera Candida and Nakaseomyces. Additionally, we observed a decrease in diversity in the lung fungal communities in patients with an active Coccidioides or Candida infection but no difference in the bacterial community. These compositional changes in the lung microbiome during an active Coccidioides spp. infection associated with shifts in the fungal community. This is the first study to examine how these fungal pathogens affect the lung microbial community of humans.
The cloacal microbiota of birds is shaped by host factors, diet, environmental exposure, and increasing overlap between wild bird habitats and human development may influence these communities. However, the effects of urbanization on herbivorous waterfowl in Illinois remain poorly understood. In this study, we characterized the cloacal microbiota of 106 Canada goose (Branta canadensis) sampled from rural and urban areas in Illinois using 16S rRNA gene V4 amplicon sequencing, and evaluated associations between host age, host sex, and human population density and microbial community structure. The cloacal microbiota included 29 phyla, 56 classes, and at least 131 orders, and was dominated by Bacillota, Actinomycetota, Pseudomonadota, and Bacteroidota. Common gutassociated taxa included Clostridium, Ruminococcus, and Eubacterium, whereas plant- and soil-associated bacteria, including nitrogen-fixing members of the Rhizobiaceae, likely reflect dietary and environmental acquisition during foraging. Alpha diversity metrics did not differ significantly across host age or sex, although ASV richness was significantly higher in rural compared to urban samples. In contrast, beta-diversity analyses indicated that host age was the strongest factor associated with differences in microbial community composition, with additional but weaker effects of human population density, while host sex had comparatively little influence. Overall, these results suggest that ecological context, including habitat type and environmental exposure, were associated with variation in the cloacal microbiota of Canada goose, although additional unmeasured environmental and spatial factors may also contribute to observed patterns. This study provides a baseline characterization of microbiota variation across age classes and habitats in Illinois Canada goose and highlights the importance of considering ecological context when interpreting wildlife-associated microbial communities.
Oil palm (Elaeis guineensis) contributes up to 3% of gross domestic product (GDP) in Malaysia. Long-term monoculture production reduced natural biodiversity and increased severe threat by Ganoderma boninense, a causal agent of basal stem rot (BSR) disease. BSR recorded projections of 860,610 hectares of plantations to be devastated by BSR by 2040. While disease management has prioritised good sanitation practices, Trichoderma spp. is a potential solution to combatting G. boninense. In this study, we determined the efficacy of Trichoderma spp. isolate 4A added to palm kernel shell (PKS) biochar (T-mix) to improve oil palm root health. Three-month-old seedlings were observed in control treatments, T1 to T4 and Trichoderma sp. treatments, T5 to 12 with Ganoderma added in T7,8, 11 and 12. Root development parameters such as root architecture, length, diameter, and surface area were observed every two months for six months. Root length of T5 (3.3 m) and T9 (4.4 m) was higher than no-treatment control, T1 (2.5 m) indicating Trichoderma sp. support of root health. T9 (T-mix) has significantly improved root architecture in root scan with denser and multiple root branches as while all other diseased oil palms exhibit stunted roots. The diameter of roots shows similar trend to root length of T9 roots with the highest reading at 5.4 mm. T11 showed the overall improved fungal biodiversity at 6 months post inoculation with potential disease suppressive effects against other common pathogens such as Fusarium sp. This study highlights a new perspective of Trichoderma spp. treatment with biochar to provide protection to growing young oil palm root health, beyond disease control, indicating a beneficial role for early application at seedling stage. For long term application, Trichoderma spp. combined with biochar support healthy fungal dynamics without over-dominating indigenous fungal inhabitants. This is the first study to highlight the role of combined Trichoderma spp. and biochar in influencing the root architecture and rhizosphere dynamics of a perennial oil palm at the seedling stage. Overall, this study presents an exciting opportunity to use a new Trichoderma sp.-biochar solution in the battle against G. boninense.
The increasing incidence of early-age-onset colorectal neoplasia (EAO-CRN) in individuals under 50 years old poses a global health concern. This study aimed to investigate the variations in the microbiota in individuals with EAO-CRN compared with a control group, utilizing stool, oral swab, and saliva samples. Participants under 50 years of age provided stool, oral swab, and saliva samples. Colorectal neoplasia was classified into the serrated lesions and adenoma-carcinoma groups based on histology and compared with a control group without polyps. The alpha diversity and the taxonomic abundance differences were assessed using amplicon sequence variants obtained through 16S rRNA sequencing and matched taxonomy data. A total of 45 participants were included: 14 in the control, 13 in the serrated lesions, and 18 in the adenoma-carcinoma groups. Microbial analysis revealed no significant differences in the alpha diversity among the groups. However, the stool samples from the serrated lesions group had higher levels of the families Erysipelotrichaceae and Lachnospiraceae compared with the control group. Analysis of the oral swabs indicated relatively elevated levels of the family Streptococcaceae in both the serrated lesions and adenoma-carcinoma groups. In the saliva samples, the serrated lesions and adenoma-carcinoma groups showed higher levels of the family Lactobacillaceae, with the serrated lesions group also exhibiting elevated levels of the family Bifidobacteriaceae. This study elucidates the microbiota changes associated with EAO-CRN, distinguishing between serrated lesions and adenoma-carcinoma groups using stool, oral swab, and saliva samples. These findings contribute to the understanding of the relationship between microbiota and colorectal neoplasia in the early-onset population.
The best way to fight harmful microbes may not lie in new antibiotics, but rather in leveraging the power of microbes themselves. Antimicrobial resistance (AMR) is a growing global concern, where the overuse of antibiotics has led to the emergence of resistant strains. This paper explores the potential of increasing diversity in gut microbiomes as natural approaches to fight AMR. The promotion microbial diversity is proposed as a promising strategy to reduce dependency on antibiotics by fostering a resilient microbial community. Strategies are discussed to address the loss of diversity caused by antibiotics including diet, probiotics, fecal transplants (FMT) and fermentation of animal/plant products. Preliminary findings from an experiment with camel milk fermentation suggest that fermentation can increase microbial diversity, potentially affecting resistance to common antibiotics such as tetracycline, streptomycin, penicillin, and chloramphenicol, and enhancing microbiome resilience, allowing it to naturally resist pathogens without additional antibiotic use. The results highlight both the benefits and potential risks fermented products. Additionally, FMT, naturally occurring in the animal world, is a promising method to restore microbiome balance and mitigating the impact of AMR. A mechanistic model is discussed to underscore the importance of maintaining microbial balance as an effective strategy for mitigating AMR and promoting long-term health. Further research are needed to better understand the mechanisms behind these changes and their implications for public health. This perspective paper calls for a shift in the approach to AMR, advocating for microbiome-based solutions as a sustainable alternative to traditional pharmaceutical interventions.