OBJECTIVE: Recent studies have overturned the traditional concept of the lung as a "sterile organ" revealing that pulmonary microbiota dysbiosis and abnormal surfactant proteins (SPs) expression are involved in the progression of silicosis. This study aimed to investigate the relationship between abnormal SPs expression and dysbiosis of lung microbiota in silica-induced lung fibrosis, providing insights into mechanisms of silicosis. METHODS: Lung pathology, SPs expression, and microbiota composition were evaluated in silica-exposed mice. A mouse model of antibiotic-induced microbiota depletion was established, and alveolar structure and SPs expression were assessed. The roles of the lung microbiota and SPs in silicosis progression were further evaluated in mice with antibiotic-induced microbiota depletion, both with and without silica exposure. RESULTS: Silica exposure induced lung inflammation and fibrosis, along with increased expression of SP-A expression. Antibiotics (Abx)-induced microbiota depletion elevated SP-A and SP-D expression. Furthermore, silica exposure altered lung microbiota composition, enriching potentially pathogenic taxa. However, antibiotic-induced microbiota depletion prior to silica exposure reduced silica-mediated lung fibrosis and inflammation. CONCLUSION Lung microbiota is associated with silica-induced lung injury. Overproduction of SP-A and SP-D, induced by Abx-induced microbiota depletion, may enhance the resistance of mouse lung tissue to silica-induced injury.
Animals ; Silicosis/prevention & control* ; Lung/metabolism* ; Mice ; Anti-Bacterial Agents/pharmacology* ; Microbiota/drug effects* ; Silicon Dioxide/toxicity* ; Mice, Inbred C57BL ; Male ; Pulmonary Surfactant-Associated Proteins/genetics*

Microbiomes in natural environments have diverse functions and harbor vast exploitable potential of modifying the nature and hosts, being significant resources for development. The inherent high complexity and uncontrollability of natural microbiomes, as well as the selection by the nature and hosts, impose significant constraints on practical applications. Synthetic microbiomes, serving as precisely defined engineered microbiomes, demonstrate enhanced functionality, stability, and controllability compared with natural microbiomes. These engineered microbiomes emerge as a prominent research focus and are potentially having applications across various fields including environmental bioremediation and host health management. Nevertheless, substantial challenges persist in both fundamental research and practical application of synthetic microbiomes. This review systematically summarizes three core design principles for synthetic microbiomes, introduces current construction strategies including top-down, bottom-up, and integrated approaches, and comprehensively lists their applications in environmental remediation, agricultural innovation, industrial biotechnology, and healthcare. Furthermore, it critically examines existing technical and conceptual challenges while proposing strategic recommendations, thereby providing theoretical guidance for future advancements in the design, engineering, and application of synthetic microbiomes.
Microbiota/genetics* ; Synthetic Biology/methods* ; Biotechnology/methods* ; Biodegradation, Environmental ; Humans

Small urban wetlands are widely distributed and susceptible to human activities, serving as important sources and sinks of carbon. Microorganisms play a crucial role in carbon cycle, while limited studies have been conducted on the microbial diversity in small urban wetlands and the functions of microbiome in carbon fixation and metabolism. To probe into the microbiome-driven carbon cycling in small urban wetlands and dissect the composition and functional groups of microbiome, we analyzed the relationships between the microbiome structure, element metabolism pathways, and habitat physicochemical properties in sediment samples across three small wetlands in Huzhou City, and compared them with natural wetlands in the Zoige wetland. High-throughput sequencing of 16S rRNA gene amplicons and metagenomics was employed to determine the species and functional groups. Sixty medium to high-quality metagenome-assembled genomes (MAGs) were constructed, including 55 bacterial and 5 archaeal taxa, and their potential in driving elemental cycles were analyzed, with a focus on carbon fixation. Several bacterial species were found to encode a nearly complete carbon fixation pathway, including the Calvin cycle, the reductive tricarboxylic acid cycle, the Wood-Ljungdahl pathway, and the reductive glycine pathway. There were several potential novel carbon-fixing bacterial members, such as those belonging to Syntrophorhabdus (Desulfobacterota) and UBA4417 (Bacteroidetes), which had high relative abundance in the wetland microbiome. Unveiling the genetic potential of these functional groups to facilitate element cycling is of great scientific importance for enhancing the carbon sequestration capacity of small urban wetlands.
Wetlands ; Microbiota/genetics* ; Carbon Cycle/genetics* ; Bacteria/classification* ; RNA, Ribosomal, 16S/genetics* ; China ; Cities ; Geologic Sediments/microbiology* ; Archaea/classification* ; Metagenomics ; Metagenome

Objective:To explore the hypothesis of "pathogen storage pool" by analyzing the local microbial community of adenoids. Methods:Under the guidance of a 70° nasal endoscope, sterile swabs were used to collect secretions from the adenoid crypts of the subjects. The samples were sent to the laboratory for DNA extraction and standard bacterial 16S full-length sequencing analysis. Results:At the species level, the top three microbial communities in adenoid crypts were Bacillus subtilis（18.78%）, Fusobacterium pyogenes（11.42%）, and Streptococcus pneumoniae（9.38%）. Conclusion:The local microbial community of adenoids exhibits a high degree of diversity, including microbial communities from the oral cavity and gastrointestinal tract. Our research results support the hypothesis that adenoids act as a " pathogen reservoir".
Humans ; Adenoids/microbiology* ; RNA, Ribosomal, 16S/genetics* ; Microbiota/genetics* ; Streptococcus pneumoniae/isolation & purification* ; Bacillus subtilis/genetics* ; DNA, Bacterial/analysis*

BACKGROUND: The profile and clinical significance of the oral microbiome in patients with non-obstructive hypertrophic cardiomyopathy (noHCM) and obstructive hypertrophic cardiomyopathy (oHCM) remain unexplored. The objective of this study was to evaluate the difference of oral microbiome between noHCM and oHCM patients. METHODS: This cross-sectional study enrolled 18 noHCM patients and 26 oHCM patients from Fuwai Hospital, Chinese Academy of Medical Sciences between 2020 and 2021. Clinical and periodontal evaluations were conducted, and subgingival plaque samples were collected. Metagenomic sequencing and subsequent microbial composition and functional analyses were performed. RESULTS: Compared to oHCM patients, those with noHCM had higher systolic blood pressure (138.1 ± 18.8 mmHg vs . 124.2 ± 13.8 mmHg, P = 0.007), a larger body circumference (neck circumference: 39.2 ± 4.0 cm vs . 35.1 ± 3.7 cm, P = 0.001; waist circumference: 99.7 ± 10.5 cm vs . 92.2 ± 10.8 cm, P = 0.027; hip circumference: 102.5 ± 5.6 cm vs . 97.5 ± 9.1 cm, P = 0.030), a greater left ventricular end-diastolic diameter (46.6 ± 4.9 mm vs . 43.1 ± 4.9 mm, P = 0.026), and a lower left ventricular ejection fraction (64.1 ± 5.7 % vs . 68.5 ± 7.8%, P = 0.048). While overall biodiversity and general microbial composition were similar between the noHCM and oHCM groups, ten taxa displayed significant differences at the genus and species levels, with Porphyromonas gingivalis showing the highest abundance and greater enrichment in noHCM (relative abundance: 7.79535 vs . 4.87697, P = 0.043). Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis identified ten distinct pathways, with pathways related to energy and amino acid metabolism being enriched in oHCM patients, and those associated with genetic information processing less abundant in the oHCM group. Metabolic potential analysis revealed ten significantly altered metabolites primarily associated with amino sugar and nucleotide sugar metabolism, porphyrin metabolism, pentose and glucuronate interconversion, and lysine degradation. CONCLUSIONS The higher abundance of Porphyromonas gingivalis , which is known to impact cardiovascular health, in noHCM patients may partially account for clinical differences between the groups. Pathway enrichment and metabolic potential analyses suggest microbial functional shifts between noHCM and oHCM patients, potentially reflecting inherent metabolic changes in HCM.
Humans ; Cardiomyopathy, Hypertrophic/microbiology* ; Female ; Male ; Microbiota/genetics* ; Middle Aged ; Cross-Sectional Studies ; Adult ; Mouth/microbiology* ; Aged

Due to the advancement of 16S rRNA sequencing technology, the lower respiratory tract microbiota, which was considered non-existent, has been revealed. The correlation between these microorganisms and diseases such as tumor has been a hot topic in recent years. As the bacteria in the surrounding can infiltrate the tumors, researchers have also begun to pay attention to the biological behavior of tumor bacteria and their interaction with tumors. In this review, we present the characteristic of the lower respiratory tract bacteria and summarize recent research findings on the relationship between these microbiota and lung cancer. On top of that, we also summarize the basic feature of bacteria in tumors and focus on the characteristic of the bacteria in lung cancer. The relationship between bacteria in lung cancer and tumor development is also been discussed. Finally, we review the potential clinical applications of bacterial communities in the lower respiratory tract and lung cancer, and summarize key points of sample collection, sequencing, and contamination control, hoping to provide new ideas for the screening and treatment of tumors.
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Humans ; Lung Neoplasms ; RNA, Ribosomal, 16S/genetics* ; Bacteria/genetics* ; Microbiota ; Respiratory System ; Lung/microbiology*

The reduction of nitrate to nitrite by the oral microbiota has been proposed to be important for oral health and results in nitric oxide formation that can improve cardiometabolic conditions. Studies of bacterial composition in subgingival plaque suggest that nitrate-reducing bacteria are associated with periodontal health, but the impact of periodontitis on nitrate-reducing capacity (NRC) and, therefore, nitric oxide availability has not been evaluated. The current study aimed to evaluate how periodontitis affects the NRC of the oral microbiota. First, 16S rRNA sequencing data from five different countries were analyzed, revealing that nitrate-reducing bacteria were significantly lower in subgingival plaque of periodontitis patients compared with healthy individuals (P < 0.05 in all five datasets with n = 20-82 samples per dataset). Secondly, subgingival plaque, saliva, and plasma samples were obtained from 42 periodontitis patients before and after periodontal treatment. The oral NRC was determined in vitro by incubating saliva with 8 mmol/L nitrate (a concentration found in saliva after nitrate-rich vegetable intake) and compared with the NRC of 15 healthy individuals. Salivary NRC was found to be diminished in periodontal patients before treatment (P < 0.05) but recovered to healthy levels 90 days post-treatment. Additionally, the subgingival levels of nitrate-reducing bacteria increased after treatment and correlated negatively with periodontitis-associated bacteria (P < 0.01). No significant effect of periodontal treatment on the baseline saliva and plasma nitrate and nitrite levels was found, indicating that differences in the NRC may only be revealed after nitrate intake. Our results suggest that an impaired NRC in periodontitis could limit dietary nitrate-derived nitric oxide levels, and the effect on systemic health should be explored in future studies.
Humans ; Nitrates ; Nitric Oxide ; Nitrites ; RNA, Ribosomal, 16S/genetics* ; Periodontitis/microbiology* ; Bacteria ; Dental Plaque/microbiology* ; Saliva/microbiology* ; Microbiota/genetics*

Objective:This study aimed to explore the possible pathogenesis of OSA from the perspective of microbiology by evaluate the change in pharyngeal microbiome of OSA children, and provide new ideas for clinical prevention, diagnosis and treatment. Methods:Randomly enrolled 20 children with OSA as OSA group and 20 children without OSA as control group. The swallow swab of each children been collected. Using 16srDNA sequencing to investigate the characteristics of pharyngeal microbiome. Results:The α-diversity showed that the Chao1and Observe-Otus index has significantly increased in the OSA group, and the β-diversity was significantly different between the two groups. The relative abundance of Haemophilus（Proteobacteria） increased but that of Veillonella（member of Firmicutes） and Prevotella-7 and Prevotella（member of Bacteroidota） decreased in the OSA group compared to control group. Conclusion:The pharyngeal microbial richness are decreased significantly and composition are disrupted in children with OSA. This microbiome analysis provides a new understanding about the pathogenesis of OSA in children.
Humans ; Sleep Apnea, Obstructive/microbiology* ; Microbiota ; Child ; Pharynx/microbiology* ; Male ; Female ; Prevotella/isolation & purification* ; Haemophilus/isolation & purification* ; Veillonella/isolation & purification* ; RNA, Ribosomal, 16S/genetics* ; Child, Preschool ; Proteobacteria/isolation & purification*

OBJECTIVES: To investigate the distribution characteristics and correlation of intestinal and pharyngeal microbiota in early neonates. METHODS: Full-term healthy neonates who were born in Shanghai Pudong New Area Maternal and Child Health Hospital from September 2021 to January 2022 and were given mixed feeding were enrolled. The 16S rRNA sequencing technique was used to analyze the stool and pharyngeal swab samples collected on the day of birth and days 5-7 after birth, and the composition and function of intestinal and pharyngeal microbiota were analyzed and compared. RESULTS: The diversity analysis showed that the diversity of pharyngeal microbiota was higher than that of intestinal microbiota in early neonates, but the difference was not statistically significant (P>0.05). On the day of birth, the relative abundance of Proteobacteria in the intestine was significantly higher than that in the pharynx (P<0.05). On days 5-7 after birth, the relative abundance of Actinobacteria and Proteobacteria in the intestine was significantly higher than that in the pharynx (P<0.05), and the relative abundance of Firmicutes in the intestine was significantly lower than that in the pharynx (P<0.05). At the genus level, there was no significant difference in the composition of dominant bacteria between the intestine and the pharynx on the day of birth (P>0.05), while on days 5-7 after birth, there were significant differences in the symbiotic bacteria of Streptococcus, Staphylococcus, Rothia, Bifidobacterium, and Escherichia-Shigella between the intestine and the pharynx (P<0.05). The analysis based on the database of Clusters of Orthologous Groups of proteins showed that pharyngeal microbiota was more concentrated on chromatin structure and dynamics and cytoskeleton, while intestinal microbiota was more abundant in RNA processing and modification, energy production and conversion, amino acid transport and metabolism, carbohydrate transport and metabolism, coenzyme transport and metabolism, and others (P<0.05). The Kyoto Encyclopedia of Genes and Genomes analysis showed that compared with pharyngeal microbiota, intestinal microbiota was more predictive of cell motility, cellular processes and signal transduction, endocrine system, excretory system, immune system, metabolic diseases, nervous system, and transcription parameters (P<0.05). CONCLUSIONS The composition and diversity of intestinal and pharyngeal microbiota of neonates are not significantly different at birth. The microbiota of these two ecological niches begin to differentiate and gradually exhibit distinct functions over time.
Humans ; Infant, Newborn ; Bacteria ; China ; High-Throughput Nucleotide Sequencing ; Intestines ; Microbiota ; Pharynx/microbiology* ; RNA, Ribosomal, 16S/genetics*

In recent years, many studies have found that vaginal microbiota is closely related to female reproductive tract diseases. However, traditional microbial culture technology has the defects of long culture cycle and most microorganisms cannot be cultured. The development of metagenomics technique has broken the limitations of culture technology, and has been gradually applied to the study of vaginal microorganisms with the characteristics of high throughput, short time, identification of microbial population structure and gene function. It also provides technical support for elucidating the relationship between vaginal microbiota and female reproductive tract diseases. This article mainly introduces the metagenomics techniques and their applications in prevention, screening and diagnosis of common female reproductive tract diseases, and discusses their promising development and limitations to be overcome.
Female ; Humans ; Microbiota/genetics* ; Vagina ; Metagenomics/methods*