Sterile Diet Causes Gut Microbiome Collapse of Cancer Patients Post Hematopoietic Cell Transplantation, But Normal Diet Recovers Them.

Though sterile diet, post-transplantation surgery is a clinical strategy for patient care to prevent the infiltration of gut pathogens, less is known about its effects on the gut microbiome. Here, the gut microbiome dynamics of leukemia patients following a 120-day "sterile-normal" diet strategy posthematopoietic cell transplantation are examined. In contrast to the traditional idea, a sterile diet leads to the lowest gut microbiota diversity (p < 0.05) and short-chain fatty acids, promoted the proliferation of potential pathogens such as Streptococcus (up by 16.93%) and Lactobacillus (up by 40.30%), and 43.32% reduction in nodes and an 85.33% reduction in edges within the microbial interaction's network. Interestingly, a normal diet allows the gut microbiome recovery and significantly promotes the abundance of beneficial bacteria. These results indicate that a sterile diet leads to a collapse of the patient's gut microbiome and promoted the proliferation of potential pathogens. This assay is a starting point for a more sophisticated assessment of the effects of a sterile diet. The work also suggests a basic principle for the re-establishment of microbial equilibrium that supplementation of microbial taxa may be the key to the restoration of the degraded ecosystem.

Different effects of seasonal impoundment and land use change on microbiome in a tributary sediment of the three gorgers reservoir.

Anthropogenic activities significantly impact river ecosystem nutrient fluxes and microbial metabolism. Here, we examined the seasonal and spatial variation of sediments physicochemical parameters and the associated microbiome in the Pengxi river, a representative tributary of Three Gorges Reservoir, in response to seasonal impoundment and land use change by human activities. Results revealed that seasonal impoundment and land use change enhanced total organic carbon (TOC), total nitrogen (TN) and ammonium nitrogen (NH4+-N) concentration in the sediment, but have different effects on sediment microbiome. Sediment microbiota showed higher similarity during the seasonal high-water level (HWL) in consecutive two years. The abundant phyla Acidobacteria, Gemmatimonadetes, Cyanobacteria, Actinobacteria and Planctomycetes significantly increased as water level increased. Along the changes in bacterial taxa, we also observed changes in predicted carbon fixation functions and nitrogen-related functions, including the significantly higher levels of Calvin cycle, 4HB/3HP cycle, 3HP cycle and assimilatory nitrate reduction, while significantly lower level of denitrification. Though land use change significantly increased TOC, TN and NH4+-N concentration, its effects on spatial variation of bacterial community composition and predicted functions was not significant. The finding indicates that TGR hydrologic changes and land use change have different influences on the carbon and nitrogen fluxes and their associated microbiome in TGR sediments. A focus of future research will be on assessing on carbon and nitrogen flux balance and the associated carbon and nitrogen microbial cycling in TGR sediment.

Viral community distribution, assembly mechanism, and associated hosts in an industrial park wastewater treatment plant.

Viruses manipulate bacterial community composition and impact wastewater treatment efficiency. Some viruses pose threats to the environment and human populations through infection. Improving the efficiency of wastewater treatment and ensuring the health of the effluent and receptor pools requires an understanding of how viral communities assemble and interact with hosts in wastewater treatment plants (WWTPs). We used metagenomic analysis to study the distribution, assembly mechanism, and sensitive hosts for the viral communities in raw water, anaerobic tanks, and returned activated sludge units of a large-scale industrial park WWTP. Uroviricota (53.42% ± 0.14%) and Nucleocytoviricota (26.1% ± 0.19%) were dominant in all units. Viral community composition significantly differed between units, as measured by ß diversity (P = 0.005). Compared to raw water, the relative viral abundance decreased by 29.8% in the anaerobic tank but increased by 9.9% in the activated sludge. Viral community assembly in raw water and anaerobic tanks was predominantly driven by deterministic processes (MST <0.5) versus stochastic processes (MST >0.5) in the activated sludge, indicating that differences in diffusion limits may fundamentally alter the assembly mechanisms of viral communities between the solid and liquid-phase environments. Acidobacteria was identified as the sensitive host contributing to viral abundance, exhibiting strong interactions and a mutual dependence (degree = 59). These results demonstrate the occurrence and prevalence of viruses in WWTPs, their different assembly mechanism, and sensitive hosts. These observations require further study of the mechanisms of viral community succession, ecological function, and roles in the successive wastewater treatment units.

Response of denitrification microbiome to the nitrogen flux in three Gorges reservoir (TGR) sediments during two seasonal water fluctuation events.

Three Gorges Reservoir (TGR) water fluctuation creates high water level (HWL) and low water level (LWL) condition in TGR aquatic ecosystem. HWL fluies significant nutrients, mainly introducing carbon and nitrogen into the ecosystem. The nitrogen input is a concern for water quality management of TGR since the possible eutrophication caused by nitrogen spike. Sediment denitrification is widely recognized as the dominant nitrogen removal process in freshwater ecosystem. Therefore, the response of TGR sediments microbiome to the input nitrogen flucatution is crucial for both nitrogen balance and the eutrophication status of the ecosystem. Using high throughout sequencing of 16S rRNA gene and the predicted denitrification enzyme, and qualitative PCR of denitrification functional genes, we investigated how TGR sediments denitrification microbiome respond to the input nitrogen flux during two seasonal water fluctuation events. Concomitant to expected input carbon and nitrogen, we observed distinct microbial community structure and denitrification microbiota in HWL and LWL, and also in seasonal sampling events. Sediments pH, total nitrogen and nitrate were the significant impact factors in shaping the microbial community structure. Important denitrification microbiota (e.g., Saprospiraceae, Gemmatimonadaceae, Pseudomonas) are the main taxa of the microbial community and also showed water level and seasonal variation. The relative abundance of denitrification enzyme (nar, nir, nor, nos) and function genes (nirS, nirK, nosZ) were higher in LWL than HWL. Denitrification enzyme were significantly (p < 0.05) correlated with the nitrate concentration. In addition, the relative abundance of denitrification enzyme and function genes increased during the transition from 2014 HWL to 2015 LWL. Results suggested that TGR sediments denitrification is nitrate concentration dependent. The denitrification microbiome is initially inhibited due to high nitrate input, then they developed denitrification ability in response to high nitrate concentration.

Antibiotics inhibit methanogenesis during municipal solid waste decomposition.

Municipal solid waste (MSW) landfills are significant sources of antibiotics. However, the effects of antibiotics on MSW decomposition process and methanogenesis during solid waste decomposition remain insufficiently characterized. This study investigated the effects of environmentally relevant concentrations (ERCs) of antibiotics (200 µg/kg for each antibiotic) on MSW decomposition and methanogenesis in bioreactors treated with and without eight antibiotics (three tetracyclines, three sulfonamides, and two macrolides). The key phases of MSW decomposition, namely the aerobic, anaerobic acid, and methanogenic phases, were determined by analyzing the key physiochemical parameters of the leachate, including pH, chemical oxygen demand, and biochemical oxygen demand. We assessed the bacterial and archaeal compositions, along with the abundance of the gene encoding the alpha subunit of methyl-coenzyme M reductase (mcrA), during MSW decomposition using high throughput 16S ribosomal RNA (rRNA) gene sequencing and quantitative polymerase chain reactions, respectively. Our results revealed that antibiotics significantly altered the compositions of bacteria and methanogens, leading to decreased mcrA abundance and methanogenesis. Specifically, antibiotics inhibited cellulose-degrading bacteria (Firmicutes) and archaea (E2) in the anaerobic acid phase and hydrolytic bacteria (Proteobacteria) in the methanogenic phase, resulting in lower degradation of biodegradable matter than that of the biodegradation without antibiotics treatment. However, the typical MSW decomposition process indicated by the key decomposition phases was successfully separated in both bioreactors, suggesting that antibiotics did not affect overall MSW decomposition process development or the associated individual decomposition phases establishment. These findings suggest that antibiotics at ERCs may inhibit methanogenesis during MSW decomposition, thereby providing fundamental information for methane management and climate change studies.

New insights on municipal solid waste (MSW) landfill plastisphere structure and function.

Plastisphere plays crucial role in global carbon and nitrogen cycles and microplastics formation. Global Municipal Solid Waste (MSW) landfills contain 42 % plastic waste, therefore representing one of the most significant plastispheres. MSW landfills are also the third largest anthropogenic methane sources and the important anthropogenic N2O source. Surprisingly, knowledge of microbiota and the associated microbial carbon and nitrogen cycles of landfill plastispheres is very limited. In this study, we characterized and compared the organic chemicals profile, bacterial community structure and metabolic pathway on plastisphere and the surrounding refuse in a large-scale landfill using GC/MS and 16S rRNA genes high-throughput sequencing, respectively. Landfill plastisphere and the surrounding refuse differed in organic chemicals composition. However, abundant phthalate-like chemicals were determined in both environments, implying the plastics additives leaching. Bacterial colonizing on the plastics surface had significantly higher richness than that in the surrounding refuse. Plastic surface and the surrounding refuse had distinct bacterial community composition. Genera of Sporosarcina, Oceanobacillus and Pelagibacterium were detected on the plastic surface with high abundance, while Ignatzschineria, Paenalcaligenes and Oblitimonas were rich in the surrounding refuse. Typical plastics biodegradation genus Bacillus, Pseudomonas and Paenibacillus were detected in both environments. However, Pseudomonas was dominant in plastic surface (up to 88.73 %), whereas Bacillus was rich in the surrounding refuse (up to 45.19 %). For the carbon and nitrogen cycle, plastisphere was predicted to had significant (P < 0.05) higher functional genes involved in carbon metabolism and nitrification, indicating more activated carbon and nitrogen microbial activity on the plastics surface. Additionally, pH was the main driver in shaping the bacterial community composition on plastic surface. These results indicate that landfill plastispheres serve as unique niches for microbial community habitation and function on microbial carbon and nitrogen cycles. These observations invite further study of the landfill plastispheres ecological effect.

Viral community in landfill leachate: Occurrence, bacterial hosts, mediation antibiotic resistance gene dissemination, and function in municipal solid waste decomposition.

A municipal solid waste (MSW) landfill is a significant source of antibiotic resistance, pathogens and viruses and also a habitat for microbial consortia that perform MSW decomposition. Viruses are of great significance in ecological interactions such as MSW decomposition and antibiotic resistance gene (ARG) transmission. In this study, the viral community structure and the associated driver, the linkage of viruses and their bacterial hosts, the virus-associated ARG dissemination and virtual community function on MSW decomposition were investigated in landfill leachate from seven cities, China. The seven cities include four megacities, two large-scale cities and one small-scale city, representing the leachate characters of China. The results showed that the leachates were dominated by the phage families Siphoviridae, Myoviridae and Podoviridae (91.7 ± 3.6) %. Their putative hosts were the important MSW decomposers Lactobacillus, Pseudomonas, Clostridium, Proteiniphilum, and Bacteroides. The structure of the viral community was significantly affected by pH (P = 0.007, analyzed by RDA) and the bacterial community (R = 0.83, P < 0.001, analyzed by Mantel test). The relative abundance of ARGs showed a strong correlation (R > 0.8, P < 0.01) with viral family, suggesting that viruses play an important role in ARGs dissemination. Phage regulate bacterial population abundance through top-down effects, thus participating in MSW decomposition. These results demonstrate that viral community are involve in ARGs transmission and dissemination and mediate MSW decomposition in landfill.

Medical image encryption based on biometric keys and lower-upper decomposition with partial pivoting.

The security of medical image transmission in telemedicine is very important to patients' privacy and health. A new asymmetric medical image encryption scheme is proposed. The medical image is encrypted by two spiral phase masks (SPM) and the lower-upper decomposition with partial pivoting, where the SPM is generated from the iris, chaotic random phase mask, and amplitude truncated spiral phase transformation. The proposed scheme has the following advantages: First, the iris is used for medical image encryption, which improves the security of the encryption scheme. Second, the combination of asymmetric optical encryption and three-dimensional Lorenz chaos improves the key space and solves the linear problem based on double-random phase encoding. Third, compared with other encryption schemes, the proposed scheme has advantages in occlusion attacks, key space, correlation, and information entropy. Numerical simulation and optical results verify the feasibility and robustness of the encryption scheme.

A miR-205-LPCAT1 axis contributes to proliferation and progression in multiple cancers.

In the past two decades, miRNAs have been demonstrated to play critical roles in development and progression of malignant diseases. To identify the role and mechanism of miRNA are urgent for the application of miRNA-based therapeutics in cancers. MiR-205 is a conserved miRNA from the invertebrate to mammalian species. Previous studies showed a large body of evidence to demonstrate the oncogenic or tumor suppressive role of it in different types of cancers. Our aim here is to clarify the role and novel mechanism of miR-205 in solid tumors. In the present study, we found that a high level of miR-205 is an independent biomarker for favorable prognosis in LIHC, HNSCC and LUSC. In the functional experiment, we stably expressed miR-205 in tumor cell lines derived from above mentioned cancers. The result showed that overexpression of miR-205 significantly inhibits cancer cell proliferation. Mechanistically, we identified that the lysophosphatidylcholine acyltransferase-1 (LPCAT1) is a novel target of miR-205 in multiple cancer cells. Furthermore, we found that LPCAT1 is required for sustained proliferation of cancer cells and a high level of it is closely associated with poor prognosis in clinical patients. Collectively, we revealed the important prognostic value of a miR-205-LPCAT1 axis in multiple cancers and highlighted an essential role of LPCAT1 in miR-205-regulated cancer cell proliferation. All these discoveries make a miR-205-LPCAT1 axis to shed light upon a potential therapeutic target in cancer treatment.