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Introduction: The oropharyngeal microbiome plays an important role in protection against infectious agents when in balance. Despite use of vaccines and antibiotic therapy to prevent respiratory tract infections, they remain one of the major causes of mortality and morbidity in Low- and middleincome countries. Hence the need to explore other approaches to prevention by identifying microbial biomarkers that could be leveraged to modify the microbiota in order to enhance protection against pathogenic bacteria. The aim of this study was to analyze the oropharyngeal microbiome (OPM) of schoolchildren in Côte d’Ivoire presenting symptoms of upper respiratory tract infections (URTI) for better prevention strategy. Methods: Primary schools’ children in Korhogo (n = 37) and Abidjan (n = 39) were followed for six months with monthly oropharyngeal sampling. Clinical diagnostic of URT infection was performed and nucleic acid extracted from oropharyngeal swabs were used for 16S rRNA metagenomic analysis and RT-PCR. Results: The clinical examination of children’s throat in Abidjan and Korhogo identified respectively 17 (43.59%) and 15 (40.54%) participants with visible symptoms of URTIs, with 26 episodes of infection in Abidjan and 24 in Korhogo. Carriage of Haemophilus influenzae (12%), Streptococcus pneumoniae (6%) and SARS-CoV-2 (6%) was confirmed by PCR. A significant difference in alpha diversity was found between children colonized by S. pneumoniae and those that were not (p = 0.022). There was also a significant difference in alpha diversity between children colonised with H. influenzae and those who were not (p = 0.017). No significant difference was found for SARS-CoV-2. Sphingomonas, Ralstonia and Rothia were significantly enriched in non-carriers of S. pneumoniae; Actinobacillus was significantly enriched in non-carriers of H. influenzae; Actinobacillus and Porphyromonas were significantly enriched in non-carriers of SARS-CoV-2 (p < 0.001). Discussion: Nearly 40% of children showed clinical symptoms of infection not related to geographical location. The OPM showed an imbalance during H. influenzae and S. pneumoniae carriage. This study provides a baseline understanding of microbiome markers in URTIs in children for future research, to develop targeted interventions aimed at restoring the microbial balance and reducing the symptoms associated with RTIs. [ABSTRACT FROM AUTHOR]

River estuaries are dynamic and complex ecosystems influenced by various natural processes, including climatic fluctuations and anthropogenic activities. The Pearl River Estuary (PRE), one of the largest in China, receives significant land-based pollutants due to its proximity to densely populated areas and urban development. This study aimed to characterize the composition, diversity, and distribution patterns of sediment microbial communities (bacteria, archaea, and eukaryotes) and investigated the connection with environmental parameters within the PRE and adjacent shelf. Physicochemical conditions, such as oxygen levels, nitrogen compounds, and carbon content, were analyzed. The study found that the microbial community structure was mainly influenced by site location and core depth, which explained approximately 67% of the variation in each kingdom. Sites and core depths varied in sediment properties such as organic matter content and redox conditions, leading to distinct microbial groups associated with specific chemical properties of the sediment, notably C/N ratio and NH4+ concentration. Despite these differences, certain dominant taxonomic groups were consistently present across all sites: Gammaproteobacteria in bacteria; Bathyarchaeia, Nitrososphaeria, and Thermoplasmata in archaea; and SAR in Eukaryota. The community diversity index was the highest in the bacteria kingdom, while the lowest values were observed at site P03 across the three kingdoms and were significantly different from all other sites. Overall, this study highlights the effect of depth, core depth, and chemical properties on sediment microbiota composition. The sensitivity and dynamism of the microbiota, along with the possibility of identifying specific markers for changes in environmental conditions, is valuable for managing and preserving the health of estuaries and coastal ecosystems. [ABSTRACT FROM AUTHOR]

Background. Routine application of the GC-MS method to assess the URT microbiota can potentially improve the efficacy and safety of treatment for chronic respiratory diseases. Aim. To perform a comparative analysis of the microbiota from the surface of the pharyngeal tonsil, from the deep parts of the nose, and saliva in children with chronic adenoiditis. Materials and methods. The study included 90 patients with chronic adenoiditis (CA) and/or pharyngeal tonsil hypertrophy (PTH). All study participants had swabs taken from the surface of the pharyngeal tonsil, from the deep parts of the nasal cavity, and saliva as a biological fluid of the oral cavity. Microorganisms were identified by specific fatty acids using GC-MS to assess the composition of the microbial community on the surface of the pharyngeal tonsil. Results. The study showed that the microbiota of the nasopharynx is identical in its qualitative composition to microorganisms from the deep parts of the nose. However, according to the results of the analysis of microbial markers of saliva, the oral microbiota showed significant differences in the quantitative and qualitative composition of microorganisms compared with the nasopharyngeal microbiota. Conclusion. The introduction of the GC-MS method for assessing the URT microbiota enables its monitoring in clinical practice for the treatment of chronic respiratory system diseases without disturbing the ecology of the mucous membranes and the whole body.

IntroductionThe oropharyngeal microbiome plays an important role in protection against infectious agents when in balance. Despite use of vaccines and antibiotic therapy to prevent respiratory tract infections, they remain one of the major causes of mortality and morbidity in Low- and middle-income countries. Hence the need to explore other approaches to prevention by identifying microbial biomarkers that could be leveraged to modify the microbiota in order to enhance protection against pathogenic bacteria. The aim of this study was to analyze the oropharyngeal microbiome (OPM) of schoolchildren in Côte d’Ivoire presenting symptoms of upper respiratory tract infections (URTI) for better prevention strategy.MethodsPrimary schools’ children in Korhogo (n = 37) and Abidjan (n = 39) were followed for six months with monthly oropharyngeal sampling. Clinical diagnostic of URT infection was performed and nucleic acid extracted from oropharyngeal swabs were used for 16S rRNA metagenomic analysis and RT-PCR.ResultsThe clinical examination of children’s throat in Abidjan and Korhogo identified respectively 17 (43.59%) and 15 (40.54%) participants with visible symptoms of URTIs, with 26 episodes of infection in Abidjan and 24 in Korhogo. Carriage of Haemophilus influenzae (12%), Streptococcus pneumoniae (6%) and SARS-CoV-2 (6%) was confirmed by PCR. A significant difference in alpha diversity was found between children colonized by S. pneumoniae and those that were not (p = 0.022). There was also a significant difference in alpha diversity between children colonised with H. influenzae and those who were not (p = 0.017). No significant difference was found for SARS-CoV-2. Sphingomonas, Ralstonia and Rothia were significantly enriched in non-carriers of S. pneumoniae; Actinobacillus was significantly enriched in non-carriers of H. influenzae; Actinobacillus and Porphyromonas were significantly enriched in non-carriers of SARS-CoV-2 (p < 0.001).DiscussionNearly 40% of children showed clinical symptoms of infection not related to geographical location. The OPM showed an imbalance during H. influenzae and S. pneumoniae carriage. This study provides a baseline understanding of microbiome markers in URTIs in children for future research, to develop targeted interventions aimed at restoring the microbial balance and reducing the symptoms associated with RTIs.

River estuaries are dynamic and complex ecosystems influenced by various natural processes, including climatic fluctuations and anthropogenic activities. The Pearl River Estuary (PRE), one of the largest in China, receives significant land-based pollutants due to its proximity to densely populated areas and urban development. This study aimed to characterize the composition, diversity, and distribution patterns of sediment microbial communities (bacteria, archaea, and eukaryotes) and investigated the connection with environmental parameters within the PRE and adjacent shelf. Physicochemical conditions, such as oxygen levels, nitrogen compounds, and carbon content, were analyzed. The study found that the microbial community structure was mainly influenced by site location and core depth, which explained approximately 67% of the variation in each kingdom. Sites and core depths varied in sediment properties such as organic matter content and redox conditions, leading to distinct microbial groups associated with specific chemical properties of the sediment, notably C/N ratio and NH4+ concentration. Despite these differences, certain dominant taxonomic groups were consistently present across all sites: Gammaproteobacteria in bacteria; Bathyarchaeia, Nitrososphaeria, and Thermoplasmata in archaea; and SAR in Eukaryota. The community diversity index was the highest in the bacteria kingdom, while the lowest values were observed at site P03 across the three kingdoms and were significantly different from all other sites. Overall, this study highlights the effect of depth, core depth, and chemical properties on sediment microbiota composition. The sensitivity and dynamism of the microbiota, along with the possibility of identifying specific markers for changes in environmental conditions, is valuable for managing and preserving the health of estuaries and coastal ecosystems.

BackgroundNon-alcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic liver disease worldwide, and gut microbes are associated with the development and progression of NAFLD. Despite numerous studies exploring the changes in gut microbes associated with NAFLD, there was no consistent pattern of changes.MethodWe retrieved studies on the human fecal microbiota sequenced by 16S rRNA gene amplification associated with NAFLD from the NCBI database up to April 2023, and re-analyzed them using bioinformatic methods.ResultsWe finally screened 12 relevant studies related to NAFLD, which included a total of 1,189 study subjects (NAFLD, n = 654; healthy control, n = 398; obesity, n = 137). Our results revealed a significant decrease in gut microbial diversity with the occurrence and progression of NAFLD (SMD = −0.32; 95% CI −0.42 to −0.21; p 0.7). The occurrence and progression of NAFLD are significantly associated with higher levels of LPS biosynthesis, tryptophan metabolism, glutathione metabolism, and lipid metabolism.ConclusionThis study elucidated gut microbes relevance to disease development and identified potential risk-associated microbes and functional pathways associated with NAFLD occurrence and progression.

BackgroundPediatric solid tumor, the abnormal proliferation of solid tissues in children resulting in the formation of tumors, represent a prevailing malignant ailment among the younger population. Extensive literature highlights the inseparable association linking oral microbiome and adult tumors, but due to differences in age of onset, characteristics of onset, etc., there are many differences between Pediatric solid tumors and adult tumors, and therefore, studying the relationship between Pediatric solid tumor and the oral microbiota is also essential.MethodsTo unravel the distinct characteristics of the oral microbiota within Pediatric solid tumor patients, 43 saliva samples, encompassing 23 Pediatric solid tumor patients and 20 healthy controls, were diligently procured. A meticulous screening process ensued, and conducted microbial MiSeq sequencing after screening.ResultsWe documented the oral microbiome attributes among pediatric diagnosed with solid tumors (PST), and meanwhile, we observed a significant trend of decreased oral microbiota diversity in the pediatric solid tumor group. There were notable disparities in microbial communities observed between the two groups, 18 genera including Veillonellaceae, Firmicutes unclassified, Coriobacteriia, Atopobiaceae, Negativicutes, were significantly enriched in PST patients, while 29 genera, including Gammaproteobacteria, Proteobacteria, Burkholderiales, Neisseriaceae, were dominant in the HCs group. It was found that PST group had 16 gene functions, including Amino acid metabolism, Cysteine and methionine metabolism, Photosynthesis antenna proteins, Arginine and proline metabolism, and Aminoacyl tRNA biosynthesi, were significantly dominant, while 29 gene functions that prevailed in HCs.ConclusionThis study characterized the oral microbiota of Pediatric solid tumor patients for the first time, and importantly, targeted biomarkers of oral microbiota may serve as powerful and non-invasive diagnostic tools for pediatric solid tumor patients.

Background: Gut microbiota is the largest population of microorganisms and is closely related to health. Many studies have explored changes in gut microbiota in viral hepatitis. However, the correlation between gut microbiota and the occurrence and progression of viral hepatitis has not been fully clarified. Methods: PubMed and BioProject databases were searched for studies about viral hepatitis disease and 16S rRNA gene sequencing of gut microbiota up to January 2023. With bioinformatics analyses, we explored changes in microbial diversity of viral hepatitis, screened out crucial bacteria and microbial functions related to viral hepatitis, and identified the potential microbial markers for predicting risks for the occurrence and progression of viral hepatitis based on ROC analysis. Results: Of the 1389 records identified, 13 studies met the inclusion criteria, with 950 individuals including 656 patient samples (HBV, n = 546; HCV, n = 86; HEV, n = 24) and 294 healthy controls. Gut microbial diversity is significantly decreased as the infection and progression of viral hepatitis. Alpha diversity and microbiota including Butyricimonas, Escherichia-Shigella, Lactobacillus, and Veillonella were identified as the potential microbial markers for predicting the risk of development of viral hepatitis (AUC>0.7). Microbial functions including tryptophan metabolism, fatty acid biosynthesis, lipopolysaccharide biosynthesis, and lipid metabolism related to the microbial community increased significantly as the development of viral hepatitis. Conclusions: This study demonstrated comprehensively the gut microbiota characteristics in viral hepatitis, screened out crucial microbial functions related to viral hepatitis, and identified the potential microbial markers for predicting the risk of viral hepatitis. [ABSTRACT FROM AUTHOR]

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Introduction. Today the search and development of new methods for diagnosing organic or functional pathology of the thyroid gland with an asymptomatic or clinically nonspecific course is an urgent task of endocrinology and therapy. The functioning of the thyroid gland and the state of the human intestinal microbiome are dynamically interrelated. One of the considered promising methods is mass spectrometry of microbial markers of the human intestinal microbiota.The purpose of the study. To study the microbial spectrum and characteristics of the biotic environment of the intestine in patients with thyroid diseases.Materials and methods. 21 patients were examined (8 men and 13 women, median age 40.5 [31.75; 54] years, respectively; 15 with thyroid disease, 6 without thyroid disease). In addition to the standard clinical and laboratory-instrumental examination, patients, colon contents were examined by chromatography-mass spectrometry of microbial materials. The work used descriptive non-parametric statistics with subsequent interpretation. Mean values of indicators and their variance are presented as median, upper and lower quartiles. In relation to representatives of the fecal microbiota, in addition to absolute values, the frequency of occurrence of the microorganism within the reference range, moderate or pronounced deviations was taken into account. The determination of the statistical significance of differences in the relative frequency value was carried out using Fisher’s exact test. The presentation of the results is implemented in the form of range diagrams, compactly depicting a one-dimensional probability distribution, tables. Results. Differences in the composition of the microbiota of the control group and the experimental group for Alcaligenes spp., Staphylococcus spp., Megamonas hypermegale, Peptostreptococcus anaerobius were revealed.Conclusions. The development of thyroid gland pathology is accompanied by significant deviations in the composition of the fecal microbiota, determined by mass spectrometry of microbial markers. In persons with thyroid pathology, in the absence of clinically significant external influences on the intestinal microbiome, a pronounced decrease in the level of Alcaligenes spp., Staphylococcus spp., is detected, a tendency to a decrease in the level of Megamonas hypermegale, Peptostreptococcus anaerobius is determined. Further differentiated study of the composition of the intestinal microbiome in patients with thyroid diseases is required, depending on the nosological affiliation and the nature of the endocrine dysfunction.

The relationship between the oral microbiota and type 1 diabetes (T1D) remains unclear. We aimed to evaluate the variations in the oral microbiome in T1D and identify potentially associated bacterial factors. We performed high-throughput sequencing of the V3-V4 area of the 16S rRNA gene to profile the oral bacterial composition of 47 healthy children (CON group), 46 children with new-onset T1D in the acute phase (NT1D group), and 10 children with T1D in the chronic phase receiving insulin treatment (CT1D group). Multivariate statistical analysis of sequencing data was performed. Compared to the CON group, the NT1D group was characterized by decreased diversity and increased abundance of genera harboring opportunistic pathogens, while this trend was partially reversed in the CT1D group. Differential genera between groups could distinguish the NT1D group from the CON group (AUC = 0.933) and CT1D group (AUC = 0.846), respectively. Moreover, T1D-enriched genera were closely correlated with HbA1c, FBG and WBCs levels. Our results showed that the acute phase of T1D was characterized by oral microbiota dysbiosis, which could be partially ameliorated via glycemic control. The possible role of oral microbiota dysbiosis on oral health and systemic metabolic status in T1D warrants further mechanistic investigation. [ABSTRACT FROM AUTHOR]

Background and Aim The relationship between the oral microbiota and type 1 diabetes (T1D) remains unclear. We aimed to evaluate the variations in the oral microbiome in T1D and identify potentially associated bacterial factors.Methods We performed high-throughput sequencing of the V3-V4 area of the 16S rRNA gene to profile the oral bacterial composition of 47 healthy children (CON group), 46 children with new-onset T1D in the acute phase (NT1D group), and 10 children with T1D in the chronic phase receiving insulin treatment (CT1D group). Multivariate statistical analysis of sequencing data was performed.Results Compared to the CON group, the NT1D group was characterized by decreased diversity and increased abundance of genera harboring opportunistic pathogens, while this trend was partially reversed in the CT1D group. Differential genera between groups could distinguish the NT1D group from the CON group (AUC = 0.933) and CT1D group (AUC = 0.846), respectively. Moreover, T1D-enriched genera were closely correlated with HbA1c, FBG and WBCs levels.Conclusion Our results showed that the acute phase of T1D was characterized by oral microbiota dysbiosis, which could be partially ameliorated via glycemic control. The possible role of oral microbiota dysbiosis on oral health and systemic metabolic status in T1D warrants further mechanistic investigation.

According to numerous studies, gut microbiota plays a significant role in multiple sclerosis (MS) development. However, data on changes in the gut microbiota in MS is often contradictory. The most common approach in gut microbiota research is the 16S ribosomal RNA sequencing of fecal microbiota. However, such data do not reflect the composition of the entire body microbiota. There is also a lack of data on microbiota markers in the cerebrospinal fluid (CSF) of patients with MS and predisposing conditions.Objective: to assess the level of microbial markers in the CSF of patients with MS and radiologically isolated syndrome (RIS).Patients and methods. We used gas chromatography-mass spectrometry (GC-MS) to evaluate microbial markers levels in eight patients with MS, five patients with RIS, and seven controls.Results and discussion. We found an increase in microbial load in patients with MS, indicating a possible association of MS with polymicrobial infection. In particular, an increase in the content of Streptococcus markers was observed, as well as a tendency to a three-fold increase in the campesterol content (a marker of campesterol-producing microfungi) in the CSF of patients with MS, compared to the control group (diagnostic punctures, various diseases of the nervous system of a non-autoimmune or inflammatory nature, not acute states).Conclusion. GC-MS of microbial markers can be used to assess the presence of microbial markers in the CSF. The CSF of patients with MS contains an increased amount of various microbial markers, which may indicate a possible association of MS with polymicrobial infection.

This study aimed to evaluate the use of total odd-chain fatty acids (OCFA) as a marker to estimate microbial nitrogen flow (MicN) and calculate the efficiency of microbial nitrogen synthesis (EMNS) in Nellore steers fed high-concentrate diets supplemented with different nitrogen supplements (NS). Ruminally and duodenally cannulated Nellore steers (n = 6; 354 ± 12 kg) were used in a 6 × 6 repeated switchback design balanced for residual effects. Treatments were arranged in a 3 × 3 factorial of three nitrogen (N) supplements (urea plus soybean meal; corn gluten meal; dried distillers' grains plus solubles) and three microbial markers (OCFA; double-labeled urea, 15N; microbial nucleic acid bases, MNAB). The total mixed ration was composed of fresh chopped sugarcane as the forage source in an 83:17 concentrate: forage ratio (dry matter basis). Linear regression was used to develop predictions of MicN from OCFA using 15N and MNAB as response variables. Microbial N flow was underestimated by the MNAB marker compared to 15N. Neither NS nor their respective interactions with the marker methods (MM) affected MicN or EMNS (P > 0.05). However, MicN was different for 15N and MNAB (P > 0.001 for both treatments). Marker methods affected EMNS in all energetic bases (total digestible carbohydrates P < 0.001; rumen-fermentable carbohydrates P < 0.001; organic matter truly degradable in the rumen P < 0.001). Equations that utilized OCFA as a regressor to predict MicN under different MM resulted in good fits of the data as observed by the coefficient of determination (R 2; 15N = 0.78; MNAB = 0.69). Microbial N flow estimated from OCFA was overpredicted (15N by 7.46%; MNAB by 4.30%) compared with observed values. The OCFA model presented a small slope bias when methodological validation was applied (15N = 0.96%; MNAB = 3.90%), ensuring reliability of the proposed alternative method. Based on the conditions of this experiment, OCFA may be a suitable alternative to other methods that quantify MicN under different dietary conditions. [ABSTRACT FROM AUTHOR]

Determining the source of body fluids is crucial in forensic investigations, as it provides valuable information about suspects and the nature of the crime. Microbial markers that trace the source of tissues and body fluids based on site specificity and temporal stability are often used effectively for this purpose. In this study, a multiplex system comprising seven microbial markers (Finegoldia magna , Corynebacterium tuberculostearicum , Cutibacterium acnes , Haemophilus parainfluenzae , Streptococcus oralis , Prevotella melaninogenica and Faecalibacterium prausnitzii) was developed to distinguish between skin, saliva, and feces samples. Based on these markers, the system produces electropherograms that are specific for each sample type. We collected 492 samples from six different skin sites (palm, antecubital crease, inguinal crease, cheek, upper back, and toe web space), the buccal mucosa, and stool were collected to further test the system. Beta diversity analysis revealed distinct clustering among the three sample groups. Additionally, skin microenvironment cluster analysis was used to identify skin sites accurately. This analysis classified skin samples into four distinct microenvironments: dry, moist, oily, and foot. Finally, we established a machine learning prediction model based on random forest regression to identify the skin microenvironment, achieving an overall prediction accuracy of 79 %. The multiplex system developed in this study accurately identifies the sources of body fluids, and the skin microenvironment. These findings offer new insights into the application of microbial markers in forensic science. • The multiplex system comprising seven microbial markers was developed based on capillary electrophoresis. • The microbial markers present good specificity and sensitivity to distinguish skin, saliva and feces. • The prediction model classified skin samples into four microenvironments, achieving an overall accuracy rate of 79 %. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths globally. Nonetheless, with early detection of CRC or its precancerous lesions, mortality, and CRC incidence can be reduced. Although colonoscopy is currently the gold standard for CRC screening and diagnosis, its invasive nature, and troublesome bowel preparation deter patient participation. Therefore, there is a need to expand the use of noninvasive or minimally invasive methods to increase patient compliance. This review summarizes advances in different methods for CRC screening, including stool bacterial and metagenomic markers, fecal proteins, genetic and epigenetic markers in blood and stools, and imaging modalities. The cost-effectiveness of these methods is also discussed. FIT is more cost-effective compared to virtual colonoscopy, mSEPT9 test, and Multitarget Stool DNA test, while the cost-effectiveness of other noninvasive methods requires further evaluation. Recent evidence has well demonstrated the usefulness of gut microbiome and certain fecal bacterial markers in the noninvasive diagnosis of CRC and its precancerous lesions. Many of the fecal biomarkers, from host cells or the gut environment, show better diagnostic sensitivity than FIT. New screening tests based on these fecal biomarkers can be expected to replace FIT with higher cost-effectiveness in the near future. [ABSTRACT FROM AUTHOR]

Autoimmune hepatitis (AIH) is a common cause of liver cirrhosis. To identify the characteristics of the oral microbiome in patients with AIH, we collected 204 saliva samples including 68 AIH patients and 136 healthy controls and performed microbial MiSeq sequencing after screening. All samples were randomly divided into discovery cohorts (46 AIH and 92 HCs) and validation cohorts (22 AIH and 44 HCs). Moreover, we collected samples of 12 AIH patients from Hangzhou for cross-regional validation. We described the oral microbiome characteristics of AIH patients and established a diagnostic model. In the AIH group, the oral microbiome diversity was significantly increased. The microbial communities remarkably differed between the two groups. Seven genera, mainly Fusobacterium, Actinomyces and Capnocytophaga, were dominant in the HC group, while 51 genera, Streptococcus, Veillonella and Leptotrichia, were enriched in the AIH group. Notably, we found 23 gene functions, including Membrane Transport, Carbohydrate Metabolism, and Glycerolipid metabolism that were dominant in AIH and 31 gene functions that prevailed in HCs. We further investigated the correlation between the oral microbiome and clinical parameters. The optimal 5 microbial markers were figured out through a random forest model, and the distinguishing potential achieved 99.88% between 46 AIH and 92 HCs in the discovery cohort and 100% in the validation cohort. Importantly, the distinguishing potential reached 95.55% in the cross-regional validation cohort. In conclusion, this study is the first to characterize the oral microbiome in AIH patients and to report the successful establishment of a diagnostic model and the cross-regional validation of microbial markers for AIH. Importantly, oral microbiota-targeted biomarkers may be able to serve as powerful and noninvasive diagnostic tools for AIH.

Autoimmune hepatitis (AIH) is a common cause of liver cirrhosis. To identify the characteristics of the oral microbiome in patients with AIH, we collected 204 saliva samples including 68 AIH patients and 136 healthy controls and performed microbial MiSeq sequencing after screening. All samples were randomly divided into discovery cohorts (46 AIH and 92 HCs) and validation cohorts (22 AIH and 44 HCs). Moreover, we collected samples of 12 AIH patients from Hangzhou for cross-regional validation. We described the oral microbiome characteristics of AIH patients and established a diagnostic model. In the AIH group, the oral microbiome diversity was significantly increased. The microbial communities remarkably differed between the two groups. Seven genera, mainly Fusobacterium, Actinomyces and Capnocytophaga , were dominant in the HC group, while 51 genera, Streptococcus, Veillonella and Leptotrichia , were enriched in the AIH group. Notably, we found 23 gene functions, including Membrane Transport, Carbohydrate Metabolism, and Glycerolipid metabolism that were dominant in AIH and 31 gene functions that prevailed in HCs. We further investigated the correlation between the oral microbiome and clinical parameters. The optimal 5 microbial markers were figured out through a random forest model, and the distinguishing potential achieved 99.88% between 46 AIH and 92 HCs in the discovery cohort and 100% in the validation cohort. Importantly, the distinguishing potential reached 95.55% in the cross-regional validation cohort. In conclusion, this study is the first to characterize the oral microbiome in AIH patients and to report the successful establishment of a diagnostic model and the cross-regional validation of microbial markers for AIH. Importantly, oral microbiota-targeted biomarkers may be able to serve as powerful and noninvasive diagnostic tools for AIH. [ABSTRACT FROM AUTHOR]

Background and Aim: The gut microbiota is associated with colorectal lesions in cases of precancer and colorectal cancer (CRC). However, there are apparent differences in studies on the gut microbiota in the pathogenic sequence from precancer to cancer. Here, we characterize the gut microbiota signatures of colorectal precancer and cancer and test their utility in detecting colorectal lesions in two independent Chinese cohorts. Methods: Stool samples collected from patients with precancer and CRC were subjected to 16S ribosomal RNA gene sequencing and metagenomic shotgun sequencing analyses, which revealed the microbial signatures of the two disease stages. Results: In comparison with healthy controls, lower microbial richness and diversity were observed in precancer and intensive interbacterial associations were found in CRC. We identified 41 bacteria that showed gradual increases while 12 bacteria showed gradual decreases at the genus level gradually during the development of CRC. Novel CRC‐associated pathogenetic species were identified. Species units that contributed to altered microbial functions were identified in CRC patients and healthy controls. The microbial panel showed a comparable ability to fecal immunochemical test (FIT) in detecting CRC. However, the combination of microbes and FIT significantly improved the detection ability and sensitivity of colon lesions based on 18 genera. Microbial network analysis revealed a significant positive correlation among beneficial microbes and a negative correlation in detrimental phenotypes. Conclusions: Microbial dysbiosis was revealed in colorectal lesions. The combination of microbial markers and FIT improved the CRC detection ability, which might assist in the early diagnosis of CRC. [ABSTRACT FROM AUTHOR]

Abstract Gut microbiota make up the largest microecosystem in the human body and are closely related to chronic metabolic diseases. Herein, 520 fecal samples are collected from different regions of China, the gut microbiome in chronic kidney disease (CKD) is characterized, and CKD classifiers based on microbial markers are constructed. Compared with healthy controls (HC, n = 210), gut microbial diversity is significantly decreased in CKD (n = 110), and the microbial community is remarkably distinguished from HC. Genera Klebsiella and Enterobacteriaceae are enriched, while Blautia and Roseburia are reduced in CKD. Fifty predicted microbial functions including tryptophan and phenylalanine metabolisms increase, while 36 functions including arginine and proline metabolisms decrease in CKD. Notably, five optimal microbial markers are identified using the random forest model. The area under the curve (AUC) reaches 0.9887 in the discovery cohort and 0.9512 in the validation cohort (49 CKD vs 63 HC). Importantly, the AUC reaches 0.8986 in the extra diagnosis cohort from Hangzhou. Moreover, Thalassospira and Akkermansia are increased with CKD progression. Thirteen operational taxonomy units are correlated with six clinical indicators of CKD. In conclusion, this study comprehensively characterizes gut microbiome in non‐dialysis CKD and demonstrates the potential of microbial markers as non‐invasive diagnostic tools for CKD in different regions of China.

Background and Purpose: Early life microbiota plays a crucial role in human health by acting as a barrier from pathogens' invasion and maintaining the intestinal immune homoeostasis. Altered fecal microbiota (FM) ecology was reported in newborns affected by intestinal ischemia. Our purpose was to describe, in these patients, the FM, the mucosal microbiota (MM) and the mucosal immunity.Methods: Fourteen newborns underwent intestinal resection because of intestinal ischemia. FM and MM were determined through targeted-metagenomics, diversity assignment and Kruskal-Wallis analyses of Operational taxonomic units (OTUs). The mucosal immune cells were analyzed through cytofluorimetry.Results and Conclusion: Based on the severity intestinal injueris we identified two groups: extensive (EII) and focal intestinal ischemia (FII). FM and MM varied in EII and FII groups, showing in the EII group the predominance of Proteobacteria and Enterobacteriaceae and the reduction of Bacteroidetes and Verrucomicrobia for both microbiota. The MM was characterized by a statistically significant reduction of Bacteroides, Lachnospiraceae and Ruminococcaceae and by a higher diversity in the EII compared to FII group. FM showed a prevalence of Proteobacteria, while the Shannon index was lower in the EII compared to FII group. An overall increment in B- and T-lymphocytes and Natural killer (NK) T-like cells was found for EII mucosal samples associated to an increment of TNF-α and INF-γ expressing cells, compared to FII group. FM and MM carry specific signatures of intestinal ischemic lesions. Further research may be crucial to address the role of specific taxa in EII, expecially with reference to inflammation grade and ischemia extension.

Gut microbiota make up the largest microecosystem in the human body and are closely related to chronic metabolic diseases. Herein, 520 fecal samples are collected from different regions of China, the gut microbiome in chronic kidney disease (CKD) is characterized, and CKD classifiers based on microbial markers are constructed. Compared with healthy controls (HC, n = 210), gut microbial diversity is significantly decreased in CKD (n = 110), and the microbial community is remarkably distinguished from HC. Genera Klebsiella and Enterobacteriaceae are enriched, while Blautia and Roseburia are reduced in CKD. Fifty predicted microbial functions including tryptophan and phenylalanine metabolisms increase, while 36 functions including arginine and proline metabolisms decrease in CKD. Notably, five optimal microbial markers are identified using the random forest model. The area under the curve (AUC) reaches 0.9887 in the discovery cohort and 0.9512 in the validation cohort (49 CKD vs 63 HC). Importantly, the AUC reaches 0.8986 in the extra diagnosis cohort from Hangzhou. Moreover, Thalassospira and Akkermansia are increased with CKD progression. Thirteen operational taxonomy units are correlated with six clinical indicators of CKD. In conclusion, this study comprehensively characterizes gut microbiome in non‐dialysis CKD and demonstrates the potential of microbial markers as non‐invasive diagnostic tools for CKD in different regions of China. [ABSTRACT FROM AUTHOR]

Background and Purpose: Early life microbiota plays a crucial role in human health by acting as a barrier from pathogens' invasion and maintaining the intestinal immune homoeostasis. Altered fecal microbiota (FM) ecology was reported in newborns affected by intestinal ischemia. Our purpose was to describe, in these patients, the FM, the mucosal microbiota (MM) and the mucosal immunity. Methods: Fourteen newborns underwent intestinal resection because of intestinal ischemia. FM and MM were determined through targeted-metagenomics, diversity assignment and Kruskal-Wallis analyses of Operational taxonomic units (OTUs). The mucosal immune cells were analyzed through cytofluorimetry. Results and Conclusion: Based on the severity intestinal injueris we identified two groups: extensive (EII) and focal intestinal ischemia (FII). FM and MM varied in EII and FII groups, showing in the EII group the predominance of Proteobacteria and Enterobacteriaceae and the reduction of Bacteroidetes and Verrucomicrobia for both microbiota. The MM was characterized by a statistically significant reduction of Bacteroides , Lachnospiraceae and Ruminococcaceae and by a higher diversity in the EII compared to FII group. FM showed a prevalence of Proteobacteria, while the Shannon index was lower in the EII compared to FII group. An overall increment in B- and T-lymphocytes and Natural killer (NK) T-like cells was found for EII mucosal samples associated to an increment of TNF-α and INF-γ expressing cells, compared to FII group. FM and MM carry specific signatures of intestinal ischemic lesions. Further research may be crucial to address the role of specific taxa in EII, expecially with reference to inflammation grade and ischemia extension. [ABSTRACT FROM AUTHOR]

We studied the levels endotoxin and microbial markers in the blood of female rats with experimental heart failure and the effects of preliminary treatment with a prebiotic complex based on fermented wheat bran and inactivated Saccharomyces cerevisiae culture on these parameters. The concentrations of endotoxin, markers of lactobacilli, and opportunistic microorganisms were found to increase in rats with experimental heart failure and significantly decreased against the background of treatment with prebiotic complex. The dynamics of markers of bifidobacteria, eubacteria, and propionibacteria were reciprocal. The observed effect of the prebiotic complex effect on gut microbiota in rats with experimental heart failure suggests that this complex can be used for the correction of intestinal dysbiosis and endotoxemia in this clinical condition. [ABSTRACT FROM AUTHOR]

Background: Pediatric solid tumor, the abnormal proliferation of solid tissues in children resulting in the formation of tumors, represent a prevailing malignant ailment among the younger population. Extensive literature highlights the inseparable association linking oral microbiome and adult tumors, but due to differences in age of onset, characteristics of onset, etc., there are many differences between Pediatric solid tumors and adult tumors, and therefore, studying the relationship between Pediatric solid tumor and the oral microbiota is also essential., Methods: To unravel the distinct characteristics of the oral microbiota within Pediatric solid tumor patients, 43 saliva samples, encompassing 23 Pediatric solid tumor patients and 20 healthy controls, were diligently procured. A meticulous screening process ensued, and conducted microbial MiSeq sequencing after screening., Results: We documented the oral microbiome attributes among pediatric diagnosed with solid tumors (PST), and meanwhile, we observed a significant trend of decreased oral microbiota diversity in the pediatric solid tumor group. There were notable disparities in microbial communities observed between the two groups, 18 genera including Veillonellaceae, Firmicutes unclassified, Coriobacteriia, Atopobiaceae, Negativicutes, were significantly enriched in PST patients, while 29 genera, including Gammaproteobacteria, Proteobacteria, Burkholderiales, Neisseriaceae, were dominant in the HCs group. It was found that PST group had 16 gene functions, including Amino acid metabolism, Cysteine and methionine metabolism, Photosynthesis antenna proteins, Arginine and proline metabolism, and Aminoacyl tRNA biosynthesi, were significantly dominant, while 29 gene functions that prevailed in HCs., Conclusion: This study characterized the oral microbiota of Pediatric solid tumor patients for the first time, and importantly, targeted biomarkers of oral microbiota may serve as powerful and non-invasive diagnostic tools for pediatric solid tumor patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Cui, Du, Cui, Fan, Pan and Wang.)

Background: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic liver disease worldwide, and gut microbes are associated with the development and progression of NAFLD. Despite numerous studies exploring the changes in gut microbes associated with NAFLD, there was no consistent pattern of changes., Method: We retrieved studies on the human fecal microbiota sequenced by 16S rRNA gene amplification associated with NAFLD from the NCBI database up to April 2023, and re-analyzed them using bioinformatic methods., Results: We finally screened 12 relevant studies related to NAFLD, which included a total of 1,189 study subjects (NAFLD, n  = 654; healthy control, n  = 398; obesity, n  = 137). Our results revealed a significant decrease in gut microbial diversity with the occurrence and progression of NAFLD (SMD = -0.32; 95% CI -0.42 to -0.21; p  < 0.001). Alpha diversity and the increased abundance of several crucial genera, including Desulfovibrio , Negativibacillus , and Prevotella , can serve as an indication of their predictive risk ability for the occurrence and progression of NAFLD (all AUC > 0.7). The occurrence and progression of NAFLD are significantly associated with higher levels of LPS biosynthesis, tryptophan metabolism, glutathione metabolism, and lipid metabolism., Conclusion: This study elucidated gut microbes relevance to disease development and identified potential risk-associated microbes and functional pathways associated with NAFLD occurrence and progression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Mai, Yang, Xie, Zhou, Wang, Wei, Yang, Lu, Ye, Cui, Liang and Huang.)

Conventional agriculture still relies on the general use of agrochemicals (herbicides, fungicides and insecticides) to control various pests (weeds, fungal pathogens and insects), to ensure the yield of crop and to feed a constantly growing population. The generalized use of pesticides in agriculture leads to the contamination of soil and other connected environmental resources. The persistence of pesticide residues in soil is identified as a major threat for in-soil living organisms that are supporting an important number of ecosystem services. Although authorities released pesticides on the market only after their careful and thorough evaluation, the risk assessment for in-soil living organisms is unsatisfactory, particularly for microorganisms for which pesticide toxicity is solely considered by one global test measuring N mineralization. Recently, European Food Safety Authority (EFSA) underlined the lack of standardized methods to assess pesticide ecotoxicological effects on soil microorganisms. Within this context, there is an obvious need to develop innovative microbial markers sensitive to pesticide exposure. Biomarkers that reveal direct effects of pesticides on microorganisms are often viewed as the panacea. Such biomarkers can only be developed for pesticides having a mode of action inhibiting a specific enzyme not only found in the targeted organisms but also in microorganisms which are considered as "non-target organisms" by current regulations. This review explores possible ways of innovation to develop such biomarkers for herbicides. We scanned the herbicide classification by considering the mode of action, the targeted enzyme and the ecotoxicological effects of each class of active substance in order to identify those that can be tracked using sensitive microbial markers. Unlabelled Image • Herbicide mode of action is depicted according to the HRAC classification. • Numerous herbicides target an enzyme found in plants and in microorganisms. • Possible effects of herbicides on soil microbial communities are described. • Targeted microbial enzymes are suggested to be used as exposure biomarkers. [ABSTRACT FROM AUTHOR]

Background: Gut microbiota is the largest population of microorganisms and is closely related to health. Many studies have explored changes in gut microbiota in viral hepatitis. However, the correlation between gut microbiota and the occurrence and progression of viral hepatitis has not been fully clarified., Methods: PubMed and BioProject databases were searched for studies about viral hepatitis disease and 16S rRNA gene sequencing of gut microbiota up to January 2023. With bioinformatics analyses, we explored changes in microbial diversity of viral hepatitis, screened out crucial bacteria and microbial functions related to viral hepatitis, and identified the potential microbial markers for predicting risks for the occurrence and progression of viral hepatitis based on ROC analysis., Results: Of the 1389 records identified, 13 studies met the inclusion criteria, with 950 individuals including 656 patient samples (HBV, n = 546; HCV, n = 86; HEV, n = 24) and 294 healthy controls. Gut microbial diversity is significantly decreased as the infection and progression of viral hepatitis. Alpha diversity and microbiota including Butyricimonas , Escherichia-Shigella , Lactobacillus , and Veillonella were identified as the potential microbial markers for predicting the risk of development of viral hepatitis (AUC>0.7). Microbial functions including tryptophan metabolism, fatty acid biosynthesis, lipopolysaccharide biosynthesis, and lipid metabolism related to the microbial community increased significantly as the development of viral hepatitis., Conclusions: This study demonstrated comprehensively the gut microbiota characteristics in viral hepatitis, screened out crucial microbial functions related to viral hepatitis, and identified the potential microbial markers for predicting the risk of viral hepatitis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yang, Mai, Zhou, Li, Wang, Lan, Lu, Yang, Guo, Ye, Cui, Liang and Huang.)

Aiming to identify factors causing the adverse health effects associated with moisture-damaged indoor environments, we analyzed immunotoxicological potential of settled dust from moisture-damaged and reference schools in relation to their microbiological composition. Mouse RAW264.7 macrophages were exposed to settled dust samples ( n = 25) collected from moisture-damaged and reference schools in Spain, the Netherlands, and Finland. After exposure, we analyzed production of inflammatory markers [nitric oxide ( NO), tumor necrosis factor- α ( TNF-) α, interleukin ( IL)-6, and macrophage inflammatory protein ( MIP)2] as well as mitochondrial activity, viability, apoptosis, and cell cycle arrest. Furthermore, particle counts, concentration of selected microbial groups as well as chemical markers such as ergosterol, 3-hydroxy fatty acids, muramic acid, endotoxins, and glucans were measured as markers of exposure. Dust from moisture-damaged schools in Spain and the Netherlands induced stronger immunotoxicological responses compared to samples from reference schools; the responses to Finnish samples were generally lower with no difference between the schools. In multivariate analysis, IL-6 and apoptosis responses were most strongly associated with moisture status of the school. The measured responses correlated with several microbial markers and numbers of particles, but the most important predictor of the immunotoxicological potential of settled dust was muramic acid concentration, a marker of Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

This paper studied associations between ocular symptoms, rhinitis, throat and dermal symptoms, headache and fatigue in students by ethnicity and in relation to exposure to chemical microbial markers and fungal DNA in vacuumed dust in schools in Malaysia. A total of 462 students from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated (96% response rate). Dust was vacuumed from 32 classrooms and analysed for levels of five types of endotoxin as 3-hydroxy fatty acids (C10, C12, C14, C16 and C18 3-OH), muramic acid, ergosterol and five sequences of fungal DNA. Multiple logistic regression was applied. Totally 11.9% reported weekly ocular symptoms, 18.8% rhinitis, 15.6% throat and 11.1% dermal symptoms, 20.6% headache and 22.1% tiredness. Totally 21.1% reported pollen or furry pet allergy (atopy) and 22.0% parental asthma or allergy. Chinese students had less headache than Malay and Indian had less rhinitis and less tiredness than Malay. Parental asthma/allergy was a risk factor for ocular (odds ratio = 3.79) and rhinitis symptoms (OR = 3.48). Atopy was a risk factor for throat symptoms (OR = 2.66), headache (OR = 2.13) and tiredness (OR = 2.02). There were positive associations between amount of fine dust in the dust samples and ocular symptoms (p < 0.001) and rhinitis (p = 0.006). There were positive associations between C14 3-OH and rhinitis (p < 0.001) and between C18 3-OH and dermal symptoms (p = 0.007). There were negative (protective) associations between levels of total endotoxin (LPS) (p = 0.004) and levels of ergosterol (p = 0.03) and rhinitis and between C12 3-OH and throat symptoms (p = 0.004). In conclusion, the amount of fine dust in the classroom was associated with rhinitis and other SBS symptoms and improved cleaning of the schools is important. Endotoxin in the school dust seems to be mainly protective for rhinitis and throat symptoms but different types of endotoxin could have different effects. The ethnic differences in symptoms among the students deserve further attention. [ABSTRACT FROM AUTHOR]

This study aimed to identify whether microbial interactions in the rectum contribute to Shiga toxin producing bacteria colonization. In total, 12 rectal digesta samples based on the previously identified Shiga toxin 2 gene (stx2) abundance (DNA) and expression (RNA) in Shiga toxin-producing bacteria (Stx2-group: detectable DNA, n=6; Stx2+ group: detectable DNA and RNA, n = 6) were subjected to microbial profiling using amplicon sequencing. Firmicutes (72.7 ± 2.0 %) and Bacteroidetes (24.6 ± 1.9 %) are the most predominant phyla of rectal microbiota, and no compositional differences were identified between two groups at the phylum level. The Shannon and Chao1 indices weren't different in rectal digesta microbial communities between two groups. Twenty-four and thirteen taxa were identified to be group-specific genera in microbial communities from Stx2- and Stx2+ group, respectively (2 out of 6, average relative abundance >0.1%). The network analysis indicated 12 and 14 keystone taxa (Generalists, densely connected with other taxa) in microbial communities between Stx2- and Stx2+ groups, respectively. Eight out of 12 and six out of 14 generalists in the Stx2- and Stx2+ group are belonging to group-specific genera, respectively. Generalists belonging to group-specific genera were broadly distributed in Stx2-network while centralized distributed in the Stx2+ network, suggesting the higher stability of the Stx2-network structure in comparison of Stx2+ network computed by the natural connectivity measurement. However, 66 core genera shared by microbial communities between two groups were not classified into network generalists. Overall, our results indicate microbial crosstalks and keystone taxa in microbial communities between two groups differed, suggesting that the microbial interactions rather than the shifts in taxa abundance may be more important affecting host. Moreover, group-specific genera play a vital ecological role in the microbial interactions, indicating the potential for being microbial markers to differentiate Shiga toxin-producing bacteria colonization in beef cattle. [ABSTRACT FROM AUTHOR]

The review is devoted to the influence of the microbiota on the development of such an age-dependent disease as coronary heart disease, the formation of which depends on atherogenesis in particular. According to the World Health Organization, cardiovascular disease is the leading cause of death worldwide. Statistical data from the Federal State Statistics Service also confirm that coronary heart disease is the leading cause of death in the Russian Federation today. It is known that the vast majority of cardiovascular diseases are atherosclerosis-associated pathologies. Atherogenesis and the state of the human gut microbiome are dynamically interrelated. The gut microbiota, which consists predominantly of bacteria, plays an important role in maintaining homeostasis. The pathogenesis of atherosclerosis is based on systemic inflammation. Aging is accompanied by a wide variety of clinical manifestations, including a basic pro-inflammatory state (i.e., «inflammation-aging»), the activity of which is maintained by the microbiota in older individuals and increases their susceptibility to diseases. Intestinal microbiocenosis in elderly and senile people differs from those of young people. In persons of older age groups, there is an increase in microorganisms secreting endotoxins lipopolysaccharide and trimethylamine-n-oxide, initiating and maintaining chronic inflammation. More research is needed to study the mechanisms of action of microbial metabolites and their clinical application in various therapeutic interventions.

The relationship between multiple sclerosis and the state of the human microbiome was studied, namely, the change in the representation of microbiota phylotypes, the proportion of coccal flora, the proportion of anaerobic, gram-negative, proteolytically active microflora, as well as the concentration of markers of bacterial plasmalogen and endotoxin in the blood. Microbiome studies were carried out by gas chromatography - mass spectrometry of microbial markers in the blood. A statistically significant increase in blood concentrations of the total level of microbial markers of bacterial plasmalogen and endotoxin was determined in multiple sclerosis, which may be associated with an increase in the permeability of the intestinal wall. In multiple sclerosis, the proportion of coccal, gram-negative, anaerobic microflora with a proteolytic type of metabolic activity increases. The correlations of the representation of microbiota phylotypes change due to the switching of the direct relationship Proteobacteria-Bacteroides to Proteobacteria-Firmicutes. In multiple sclerosis, Actinobacteria and Proteobacteria increase and Firmicutes decrease. Conclusion. The multiple sclerosis disease may be associated with pathological changes in the structure of the microbiome and the growth of endotoxemia, which may be one of the factors in the pathogenesis of the disease. New laboratory markers for diagnosing and predicting the course of MS have been proposed., Competing Interests: The authors declare no conflict of interest.

Abstract: Previous research has demonstrated that cigarette smoke contains bacterial and fungal components including lipopolysaccharide (LPS) and ergosterol. In the present study we used gas chromatography–mass spectrometry to analyze tobacco as well as mainstream and second hand smoke for 3-hydroxy fatty acids (3-OH FAs) of 10 to 18 carbon chain lengths, used as LPS markers, and ergosterol, used as a marker of fungal biomass. The air concentrations of LPS were 0.0017nmol/m3 (N=5) and 0.0007/m3 (N=6) in the smoking vs. non-smoking rooms (p=0.0559) of the studied private houses, and 0.0231nmol/m3 (N=5) vs. 0.0006nmol/m3 (N=5) (p=0.0173), respectively, at the worksite. The air concentrations of ergosterol were also significantly higher in rooms with ongoing smoking than in rooms without smoking. A positive correlation was found between LPS and ergosterol in rooms with smoking but not in rooms without smoking. 3-OH C14:0 was the main 3-OH FA, followed by 3-OH C12:0, both in mainstream and second hand smoke and in phenol:water smoke extracts prepared in order to purify the LPS. The Limulus activity of the phenolic phase of tobacco was 3900endotoxin units (EU)/cigarette; the corresponding amount of the smoke, collected on filters from 8 puffs, was 4EU/cigarette. Tobacco smoking has been associated with a range of inflammatory airway conditions including COPD, asthma, bronchitis, alveolar hypersensitivity etc. Significant levels of LPS and ergosterol were identified in tobacco smoke and these observations support the hypothesis that microbial components of tobacco smoke contribute to inflammation and airway disease. [Copyright &y& Elsevier]

Abstract: Improving the microbiological quality of coastal and river waters relies on the development of reliable markers that are capable of determining sources of fecal pollution. Recently, a principal component analysis (PCA) method based on six stanol compounds (i.e. 5β-cholestan-3β-ol (coprostanol), 5β-cholestan-3α-ol (epicoprostanol), 24-methyl-5α-cholestan-3β-ol (campestanol), 24-ethyl-5α-cholestan-3β-ol (sitostanol), 24-ethyl-5β-cholestan-3β-ol (24-ethylcoprostanol) and 24-ethyl-5β-cholestan-3α-ol (24-ethylepicoprostanol)) was shown to be suitable for distinguishing between porcine and bovine feces. In this study, we tested if this PCA method, using the above six stanols, could be used as a tool in “Microbial Source Tracking (MST)” methods in water from areas of intensive agriculture where diffuse fecal contamination is often marked by the co-existence of human and animal sources. In particular, well-defined and stable clusters were found in PCA score plots clustering samples of “pure” human, bovine and porcine feces along with runoff and diluted waters in which the source of contamination is known. A good consistency was also observed between the source assignments made by the 6-stanol-based PCA method and the microbial markers for river waters contaminated by fecal matter of unknown origin. More generally, the tests conducted in this study argue for the addition of the PCA method based on six stanols in the MST toolbox to help identify fecal contamination sources. The data presented in this study show that this addition would improve the determination of fecal contamination sources when the contamination levels are low to moderate. [Copyright &y& Elsevier]

The use of specific DNA sequences (DS) as a microbial marker in post-rumen digesta requires their persistence and integrity throughout gastric digestion. The aim of this study was to evaluate in vitro the survival of microbial DS during gastric digestion and the factors involved. Gastric pH had a highly significant effect on the integrity of DS. pH 4.2 allows for a significant growth of microbes in the medium, but at pH 1.2, almost all of the DS were hydrolysed. In the presence of carboxymethylcellulose, the effect of pH was reduced, pepsin activity was inhibited and gene survival increased considerably. In the simulated abomasal conditions (pH = 2.3, 2 g/l of carboxymethylcellulose, and 40-min retention time), almost all of the bacterial genes and around 78% of the protozoa gene sequences retained their molecular integrity throughout gastric digestion, although factors such as acidity and viscera retention time might compromise the utilisation of DS as a microbial marker. [ABSTRACT FROM AUTHOR]

Abstract: This study sought to distinguish liquid-(LAB) and detached (SAB1) and undetached (SAB2) solid-associated bacteria through their fatty acid (FA) and purine base (PB) profiles. Fatty acids and PB were also evaluated as internal microbial markers for estimating microbial biomass associated with rumen particles. Four merino rams fitted with rumen cannulae and fed dehydrated alfalfa pellets provided rumen contents. In 3 consecutive weeks, rumen contents were collected and samples of LAB and SAB1, total rumen content (TRC), washed rumen particles (WRP) and rumen particles after SAB1 extraction (ERP) were obtained and analysed for PB and FA. The SAB2 biomass composition was estimated from the non-NDF organic matter (OM) remaining in ERP. The concentration of total SAB biomass in particles was estimated using both PB and odd and branched-chain fatty acids (OBCFA). Concentrations of PB and OBCFA were highly correlated among the different rumen fractions. Marked differences between LAB and SAB populations occurred with LAB having higher PB content, lower FA content and a higher proportion (g/100g fatty acids) of OBCFA than did SAB. The chemical composition of SAB1 and SAB2 was similar, except for the 15% higher crude protein content of the latter. The concentration of OBCFA (mg/g microbial OM) did not differ between bacterial fractions. The PB/OBCFA ratio (mg/mg) was higher in LAB (2.08) than in SAB (0.94). The ratio between branched-chain and odd-linear-chain FA was higher in LAB (2.26) than in SAB (1.46). Extraction of PB and OBCFA from WRP with our SAB detachment procedure was 61% and 31%, respectively. Estimated SAB1 and total SAB biomass (mg OM/g WRP) were 158 and 266, and 47 and 164, respectively, using PB and OBCFA as microbial markers. This study suggests that the OBCFA have potential as internal microbial markers in rumen ecosystem studies. [Copyright &y& Elsevier]

The microbial protein in the rumen is expressed in the yield or the efficiency of synthesis and is related with the quantity of energy in the ATP form used during such process, the quantity of substrate fermented or the available nitrogen in the rumen. These two measures are going to be affected by the rate of growth of the microorganisms and by the factors that influence on the microbial synthesis. The trust of the models of prediction of the microbial protein synthesis is increased by taking into account the factors that influence on the microbial synthesis. However, it results to be risky extrapolatein the experimental results to real situations of production, thus, models should be developed according to the results obtained in such conditions. To attain estimates that can be trusted of the production of microbial protein, it has been developed the not invasive method of the puric derivatives as microbial markers measured in the urine. The combination of the technique of in vitro gas production as microbial markers or with the determination of the truly degradated substrate and the called factor of partition are other forms of estimate the efficiency of microbial synthesis. The results obtained has been restricted, due to limitations of such methods. Moreover, the majority of the models have been developed in conditions of template countries (breed of the animals, feeding and climate), which reduce their possibilities of application in the tropic. It is presicely in this region where it is made more necessary the search and evaluation of new sources of feeds. Before this reality, it is imposed to search new challenges in the development and application of in vitro methods that, combined to molecular techniques, permit elucidate the mechanisms from the microbial interactions and predict in vivo processes. [ABSTRACT FROM AUTHOR]

The origin of post-ruminal purine bases (PB) was studied in 24 growing lambs that were given a pelleted concentrate plus barley straw (C) or whole barley grain plus protein supplement (WB). Six lambs from each treatment were slaughtered at 10 and 30 days post weaning after 15N labelling of microbial nitrogen (N) and PB. Microbial contribution to digesta non-ammonia N (NAN) and PB was lower (P < 0.01) when estimated from duodenal rather than abomasal samples (0.36 v. 0.52 (s.e.d. 0.021) for NAN and 0.47 v. 0.77 (s.e.d. 0.029) for PB) as a result of endogenous contamination. In comparison with 15N, total PB/N led to higher estimates (P < 0.01) of microbial contribution to abomasal NAN in WB treatment (0.62 v. 0.46 s.e.d. 0.049). The difference was removed after correcting for microbial PB, while this effect was not observed with < the C diet, resulting in a marker by diet interaction (P < 0.05). Abomasal PB flow increased (P < 0.1) from 10 to 30 days after weaning mainly due to the higher proportion of microbial PB (0.70 v.0.81 (s.e.d. 0.047)). Rumen apparent PB degradation did not differ between diets in older lambs,but it was proportionally 0.39 lower for WB treatment (P < 0.05) in younger lambs. When the microbial PB flow was estimated indirectly from labelled microbial N and the PB/N ratio of bacterial extracts the estimates were in agreement with those derived from PB-15N in the WB treatment but resulted in unrealistic values in lambs on diet C. Results suggest that significant proportions of dietary PB can escape rumen degradation which may lead to overestimation of microbial contribution to abomasal NAN when the PB/N ratio is used as marker. The extent of the overestimation is affected by the lamb age and grain processing. [ABSTRACT FROM AUTHOR]

It is known that under conditions of ultra-high physical activity and a specific diet, the state of the microbiota plays a significant role in maintaining the health, metabolic and energy status of athletes. The purpose of the study was to evaluate the composition of blood microbial markers in professional football players and physically active people and their correlation with diets in order to substantiate recommendations for their optimization. Material and methods . In a cross-sectional study a group of football players (n=24, 28±3 years old, body mass index - 22.5±1.0 kg/m 2 ) who received a diet according to the training regimen, and a comparison group of physically active individuals (n=25, 34±5 years old, body mass index - 21.8±2.8 kg/m 2 ) have been examined. The method of gas chromatography-mass spectrometry was used to analyze microbial markers of microbiome, mycobiome, virome and blood metabolome populations. Data on actual dietary intake were collected using food diaries for 3 days, followed by data processing with the Nutrium 2.13.0 nutritional computer program. For analysis, individual daily requirements for energy and macronutrients have been calculated based on the basal metabolic rate (according to the Mifflin-San Geor formula, taking into account anthropometric data), the coefficient of physical activity (groups IV and II, respectively). Results . The analysis of the athletes' diet, compared with individual requirements and with the recommendations of the International Society for Sports Nutrition (ISSN), revealed a lack of complex carbohydrates (5±1 instead of 6.1±0.3 g/kg body weight day), an excess of sugars (23±4 instead of <10% of kcal). These figures are significantly higher than the intake of similar nutrients in physically active people in the comparison group. In football players, compared with the comparison group, significant changes in microbial markers were found for Alcaligenes spp., Clostridium ramosum, Coryneform CDC-group XX, Staphylococcus epidermidis (p<0.001), known for their pro-inflammatory activity in the intestine, as well as for Lactobacillus spp. (p<0.001) performing a protective function. In addition, mycobiome markers were increased in athletes: Candida spp. (p<0.001), Aspergillus spp. (p<0.001), among which there are potential pathogens of mycoses. This was not observed in the comparison group. At the same time, an increase in the microbial markers of Alcaligenes spp., Coryneform CDC-group XX, Lactobacillus spp., Streptomyces spp., Candida spp. Micromycetes spp., containing campesterol in the cell wall, in football players positively correlated with a high calorie diet (p<0.001). A similar correlation of mycobiome markers (Micromycetes spp., containing sitosterol in the cell wall, ρ=0.346, p=0.015) was observed with an excess of easily digestible carbohydrates. Taking into account the data obtained, a correction of the diet have been proposed: increasing the consumption of carbohydrates to 7.3-7.5 g/kg of body weight/day by including bakery products from whole grain flour and cereals in the diet (up to 300-370 g/day), limiting simple sugars (up to 90-95 g/day). Conclusion . High physical activity leads to changes in the structure of blood microbial markers, including a shift towards an increase in potentially pathogenic fungi. Wherein, a predictive role is played by an imbalance of macronutrients in terms of quantitative and qualitative composition, an excess of simple sugars, and a lack of slowly digestible carbohydrates. To correct the diet, an additional inclusion in the diet of their main sources - products from cereals (cereals and bakery products) is proposed., Competing Interests: The authors declare no overt and potential conflict of interest related to the publication of this article., (Copyright© GEOTAR-Media Publishing Group.)