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*

Humans ; Gastrointestinal Microbiome ; Constipation/therapy* ; Probiotics/therapeutic use* ; Patients

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*

Routine intimate hygiene care has a major contribution in maintaining overall urogenital and perineal health in women. However, Filipino women continue to experience a major surge in vulvar and vaginal symptoms across all age groups, in a context of major changes in lifestyles and risk factors impacting their genital health. Personal beliefs, preferences, apprehensions to discuss intimate topics with health care practitioners (HCPs), availability of cleansing products in the market, and their affordability prevent many women from discussing the role of intimate hygiene care with their HCPs. Communication difficulties and lack of robust evidence, supporting optimal hygiene recommendations are some of the challenges experienced by HCPs. Through this review, the authors discuss the following factors: (i) Differing physiological needs and pathological effects that result from changing dynamics of microflora in the vulvar, perineal, and vaginal region across all age groups of women, (ii) Importance of focusing on perianal and perineal hygiene, and bowel habits, to improve the quality of vulvar hygiene and genital health, (iii) Designing approaches for HCPs to maintain genital health in the light of intimate hygiene, (iv) Recommending improvements in HCP-patient communications to help HCPs dispel the misconceptions pertaining to intimate hygiene practices, and (v) Highlighting the antimicrobial efficacy of feminine hygiene cleansers that preserve the natural microbiome and help maintain the vaginal pH within the normal range. These strategies can fill the knowledge gaps among HCPs, women, and their caregivers’ perspectives and help achieve optimal intimate hygiene.

Bacillus cereus is a common foodborne pathogen. Accidently eating food contaminated by B. cereus will cause vomiting or diarrhea, and even death in severe cases. In the present study, a B. cereus strain was isolated from spoiled rice by streak culture. The pathogenicity and drug resistance of the isolated strain were analyzed by drug sensitivity test and PCR amplification of virulence-associated gene respectively. Cultures of the purified strain were injected intraperitoneally into mice to examine their effects on intestinal immunity-associated factors and gut microbial communities, to provide references for the pathogenic mechanism and medication guidance of these spoilage microorganisms. The results showed that the isolated B. cereus strain was sensitive to norfloxacin, nitrofurantoin, tetracycline, minocycline, ciprofloxacin, spectinomycin, clindamycin, erythrocin, clarithromycin, chloramphenicol, levofloxacin, and vancomycin, but resistant to bactrim, oxacillin and penicillin G. The strain carries seven virulence-associated genes including hblA, hblC, hblD, nheA, nheB, nheC and entFM, which are involved in diarrhea-causing toxins production. After infecting mice, the isolated B. cereus strain was found to cause diarrhea in mice, and the expression levels of immunoglobulins and inflammatory factors in the intestinal mucosae of the challenged mice were significantly up-regulated. Gut microbiome analysis showed that the composition of gut microbial community in mice changed after infection with B. cereus. The abundance of the uncultured_bacterium_f_Muribaculaceae in Bacteroidetes, which is a marker of body health, was significantly decreased. On the other hand, the abundance of uncultured_bacterium_f_Enterobacteriaceae, which is an opportunistic pathogen in Proteobacteria and a marker of dysbacteriosis, was significantly increased and was significantly positively correlated with the concentrations of IgM and IgG. These results showed that the pathogenic B. cereus carrying diarrhea type virulence-associated gene can activate the immune system by altering the composition of gut microbiota upon infection.
Animals ; Mice ; Bacillus cereus/metabolism* ; Food Microbiology ; Immunity, Mucosal ; Diarrhea ; Microbiota ; Enterotoxins/genetics*

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.
Polyethylene/metabolism* ; Bacteria/metabolism* ; Plastics/metabolism* ; Biodegradation, Environmental ; Microbial Consortia

There are a large number of natural microbial communities in nature. Different populations inside the consortia expand the performance boundary of a single microbial population through communication and division of labor, reducing the overall metabolic burden and increasing the environmental adaptability. Based on engineering principles, synthetic biology designs or modifies basic functional components, gene circuits, and chassis cells to purposefully reprogram the operational processes of the living cells, achieving rich and controllable biological functions. Introducing this engineering design principle to obtain structurally well-defined synthetic microbial communities can provide ideas for theoretical studies and shed light on versatile applications. This review discussed recent progresses on synthetic microbial consortia with regard to design principles, construction methods and applications, and prospected future perspectives.
Microbial Consortia/genetics* ; Synthetic Biology ; Microbiota ; Models, Theoretical

To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.
Denitrification ; Wastewater ; Anaerobic Ammonia Oxidation ; Nitrogen ; Oxidation-Reduction ; Bioreactors/microbiology* ; Ammonium Compounds ; Bacteria/genetics* ; Microbiota ; Sewage

Objective To analyze the genetic subtypes of human immunodeficiency virus (HIV) and the prevalence of pretreatment drug resistance in the newly reported HIV-infected men in Guangxi. Methods The stratified random sampling method was employed to select the newly reported HIV-infected men aged≥50 years old in 14 cities of Guangxi from January to June in 2020.The pol gene of HIV-1 was amplified by nested reverse transcription polymerase chain reaction and then sequenced.The mutation sites associated with drug resistance and the degree of drug resistance were then analyzed. Results A total of 615 HIV-infected men were included in the study.The genetic subtypes of CRF01_AE,CRF07_BC,and CRF08_BC accounted for 57.4% (353/615),17.1% (105/615),and 22.4% (138/615),respectively.The mutations associated with the resistance to nucleoside reverse transcriptase inhibitors (NRTI),non-nucleoside reverse transcriptase inhibitors (NNRTI),and protease inhibitors occurred in 8 (1.3%),18 (2.9%),and 0 patients,respectively.M184V (0.7%) and K103N (1.8%) were the mutations with the highest occurrence rates for the resistance to NRTIs and NNRTIs,respectively.Twenty-two (3.6%) patients were resistant to at least one type of inhibitors.Specifically,4 (0.7%),14 (2.3%),4 (0.7%),and 0 patients were resistant to NRTIs,NNRTIs,both NRTIs and NNRTIs,and protease inhibitors,respectively.The pretreatment resistance to NNRTIs had much higher frequency than that to NRTIs (2.9% vs.1.3%;χ²=3.929,P=0.047).The prevalence of pretreatment resistance to lamivudine,zidovudine,tenofovir,abacavir,rilpivirine,efavirenz,nevirapine,and lopinavir/ritonavir was 0.8%, 0.3%, 0.7%, 1.0%, 1.3%, 2.8%, 2.9%, and 0, respectively. Conclusions CRF01_AE,CRF07_BC,and CRF08_BC are the three major strains of HIV-infected men≥50 years old newly reported in Guangxi,2020,and the pretreatment drug resistance demonstrates low prevalence.
Male ; Humans ; Middle Aged ; Reverse Transcriptase Inhibitors/therapeutic use* ; HIV Infections/drug therapy* ; Drug Resistance, Viral/genetics* ; China/epidemiology* ; Mutation ; HIV-1/genetics* ; Protease Inhibitors/therapeutic use* ; Genotype

Genkwa Fols, Kansui Radix, and Euphorbiae Pekinensis Radix in Shizao Decoction(SZD) are toxic to intestinal tract. Jujubae Fructus in this prescription can alleviate the toxicity, but the mechanism is still unclear. Therefore, this study aims to explore the mechanism. To be specific, 40 normal Sprague-Dawley(SD) rats were classified into the normal group, high-dose and low-dose SZD groups, and high-dose and low-dose SZD without Jujubae Fructus(SZD-JF) groups. The SZD groups were given(ig) SZD, while SZD-JF groups received the decoction without Jujubae Fructus. The variation of body weight and spleen index were recorded. The patho-logical changes of intestinal tissue were observed based on hematoxylin and eosin(HE) staining. The content of malondialdehyde(MDA) and glutathione(GSH) and activity of superoxide dismutase(SOD) in intestinal tissue were measured to evaluate the intestinal injury. Fresh feces of rats were collected to detect intestinal flora structure by 16S ribosomal RNA gene(16S rDNA) sequencing technology. The content of fecal short chain fatty acids and fecal metabolites was determined by gas chromatography-mass spectrometer(GC-MS) and liquid chromatography-mass spectrometer ultra-fast liquid chromatography-quadrupole-time-of-flight mass spectrometer(UFLC-Q-TOF-MS), separately. Spearman's correlation analysis was employed to analyze the differential bacteria genera and differential metabolites. RESULTS:: showed that high-dose and low-dose SZD-JF groups had high content of MDA in intestinal tissue, low GSH content and SOD activity, short intestinal villi(P<0.05), low diversity and abundance of intestinal flora, variation in the intestinal flora structure, and low content of short chain fatty acids(P<0.05) compared with the normal group. Compared with high-dose and low-dose SZD-JF groups, high-dose and low-dose SZD groups displayed low content of MDA in intestinal tissue, high GSH content and SOD activity, recovery of the length of intestinal villi, increased abundance and diversity of intestinal flora, alleviation of dysbacteria, and recovery of the content of short chain fatty acids(P<0.05). According to the variation of intestinal flora and fecal metabolites after the addition of Jujubae Fructus, 6 differential bacterial genera(Lactobacillus, Butyricimonas, Clostridia＿UCG-014, Prevotella, Escherichia-Shigella, Alistipes),4 differential short chain fatty acids(such as acetic acid, propionic acid, butyric acid, valeric acid) and 18 differential metabolites(such as urolithin A, lithocholic acid, and creatinine) were screened out. Beneficial bacteria such as Lactobacillus were in positive correlation with butyric acid and urolithin A(P<0.05). The pathogenic bacteria such as Escherichia-Shigella were in negative correlation with propionic acid and urolithin A(P<0.05). In summary, SZD-JF caused obvious intestinal injury to normal rats, which could lead to intestinal flora disorder. The addition of Jujubae Fructus can alleviate the disorder and relieve the injury by regulating intestinal flora and the metabolites. This study discusses the effect of Jujubae Fructus in relieving the intestinal injury caused by SZD and the mechanism from the perspective of intestinal flora-host metabolism, which is expected to serve as a reference for clinical application of this prescription.
Rats ; Animals ; Rats, Sprague-Dawley ; Propionates/pharmacology* ; Gastrointestinal Microbiome ; Fatty Acids, Volatile/pharmacology* ; Butyrates/pharmacology*