Alterations in nasal microbiota of patients with amyotrophic lateral sclerosis / 中华医学杂志(英文版)

BACKGROUND@#Links between alterations in gut microbiota composition and amyotrophic lateral sclerosis (ALS) have previously been reported. This study aimed to examine the microbiota in the nasal cavity of ALS.@*METHODS@#Sixty-six ALS patients and 40 healthy caregivers who live in close proximity with patients were enrolled. High throughput metagenomic sequencing of the 16S ribosomal deoxyribonucleic acid (rDNA) gene V3-V4 region of nasal microbiota was used to characterize the alpha and beta diversity and relative abundance of bacterial taxa, predict function, and conduct correlation analysis between specific taxa and clinical features.@*RESULTS@#The nasal microbiome of ALS patients showed lower alpha diversity than that of corresponding healthy family members. Genera Gaiella , Sphingomonas , Polaribacter _1, Lachnospiraceae _NK4A136_group, Klebsiella , and Alistipes were differentially enriched in ALS patients compared to controls. Nasal microbiota composition in ALS patients significantly differed from that in healthy subjects (unweighted UniFrac P = 0.001), while Linear discriminant analysis Effect Size (LEfSe) analysis indicated that Bacteroidetes and Firmicutes dominated healthy nasal communities at the phylum level, whereas Actinobacteria was the predominant phylum and Thermoleophilia was the predominant class in ALS patients. Genus Faecalibacterium and Alistipes were positively correlated with ALS functional rating scale revised (ALSFRS-R; rs = 0.349, P = 0.020 and rs = 0.393, P = 0.008), while Prevotella -9 and Bacteroides operational taxonomic units (OTUs) were positively associated with lung function (FVC) in ALS patients ( rs = 0.304, P = 0.045, and rs = 0.300, P = 0.048, respectively). Prevotella -1 was positively correlated with white blood cell counts (WBC, rs = 0.347, P = 0.021), neutrophil percentage (Neu%, rs = 0.428, P = 0.004), and neutrophil-to-lymphocyte ratio (NLR, rs = 0.411, P = 0.006), but negatively correlated with lymphocyte percentage (Lym%, rs = -0.408, P = 0.006). In contrast, Streptococcus was negatively associated with Neu% ( rs = -0.445, P = 0.003) and NLR ( rs = -0.436, P = 0.003), while positively associated with Lym% ( rs = 0.437, P = 0.003). No significant differences in nasal microbiota richness and evenness were detected among the severe and mild ALS patients.@*CONCLUSIONS@#ALS is accompanied by altered nasal microbial community composition and diversity. The findings presented here highlight the need to understand how dysbiosis of nasal microbiota may contribute to the development of ALS.

Association between gut microbiome and intracerebral hemorrhage based on genome-wide association study data / 中南大学学报(医学版)

OBJECTIVES@#Intracerebral hemorrhage (ICH) has the highest mortality and disability rates among various subtypes of stroke. Previous studies have shown that the gut microbiome (GM) is closely related to the risk factors and pathological basis of ICH. This study aims to explore the causal effect of GM on ICH and the potential mechanisms.@*METHODS@#Genome wide association study (GWAS) data on GM and ICH were obtained from Microbiome Genome and International Stroke Genetics Consortium. Based on the GWAS data, we first performed Mendelian randomization (MR) analysis to evaluate the causal association between GM and ICH. Then, a conditional false discovery rate (cFDR) method was conducted to identify the pleiotropic variants.@*RESULTS@#MR analysis showed that Pasteurellales, Pasteurellaceae, and Haemophilus were negatively correlated with the risk of ICH, whileVerrucomicrobiae, Verrucomicrobiales, Verrucomicrobiaceae, Akkermansia, Holdemanella, and LachnospiraceaeUCG010 were positively correlated with ICH. By applying the cFDR method, 3 pleiotropic loci (rs331083, rs4315115, and rs12553325) were found to be associated with both GM and ICH.@*CONCLUSIONS@#There is a causal association and pleiotropic variants between GM and ICH.

Characteristics of intestinal flora in patients with cerebral infarction complicated with Type 2 diabetes mellitus / 中南大学学报(医学版)

OBJECTIVES@#The intestinal microbial characteristics of patients with simple cerebral infarction (CI) and CI complicated with Type 2 diabetes mellitus (CI-T2DM) are still not clear. This study aims to analyze the differences in the variable characteristics of intestinal flora between patients simply with CI and CI-T2DM.@*METHODS@#This study retrospectively collected the patients who were admitted to the Affiliated Hospital of Putian University from September 2021 to September 2022. The patients were divided into a CI group (n=12) and a CI-T2DM group (n=12). Simultaneously, 12 healthy people were selected as a control group. Total DNA was extracted from feces specimens. Illumina Novaseq sequencing platform was used for metagenomic sequencing. The Knead Data software, Kraken2 software, and Bracken software were applied for sequencing analysis.@*RESULTS@#At phylum level, the average ratio of Firmicutes, Bacteroidetes, and Proteobacteria in the CI-T2DM group were 33.07%, 54.80%, and 7.00%, respectively. In the CI group, the ratios of each were 14.03%, 69.62%, and 11.13%, respectively, while in the control group, the ratios were 50.99%, 37.67%, and 5.24%, respectively. There was significant differences in the distribution of Firmicutes (F=6.130, P=0.011) among the 3 groups. At the family level, compared with the CI group, the relative abundance of Eubacteriaceae (t=8.062, P<0.001) in the CI-T2DM group was significantly increased, while Corynebacteriaceae (t=4.471, P<0.001), Methanobacteriaceae (t=3.406, P=0.003), and Pseudomonadaceae (t=2.352, P=0.028) were decreased significantly. At the genus level, compared with the CI group, there was a relative abundance of Cutibacterium (t=6.242, P<0.001), Eubacterium (t=8.448, P<0.001), and Blautia (t=3.442, P=0.002) in the CI-T2DM group which was significantly increased. In terms of Methanobrevibacter (t=3.466, P=0.002), Pyramidobacter (t=2.846, P=0.009) and Pseudomonas (t=2.352, P=0.028), their distributions were decreased significantly in the CI-T2DM group. At the species level, compared with the CI group, the relative abundance of Cutibacterium acnes (t=6.242, P<0.001) in the CI-T2DM group was significantly increased, while Pseudomonas aeruginosa (t=2.352, P=0.028) was decreased significantly. Still at the genus level, linear discriminant analysis effect size (LEfSe) analysis showed that the distributions of Pseudomonas and Blautia were determined to be the most significantly different between the CI-T2DM and the CI group. At the species level, the total number of operational taxonomic units (OTUs) in the 3 groups was 1 491. There were 169, 221, and 192 kinds of OTUs unique to the CI-T2DM, CI, and control group, respectively.@*CONCLUSIONS@#From phylum level to species level, the composition of intestinal flora in the patients with CI-T2DM is different from those in the patients simply with CI. The change in the proportion of Firmicutes, Bacteroidetes and Proteus compared with the healthy population is an important feature of intestinal flora imbalance in the patients with CI and with CI-T2DM. Attention should be paid to the differential distribution of Bacteroides monocytogenes and butyrate producing bacteria.

Metagenomic and targeted metabolomic analyses reveal distinct phenotypes of the gut microbiota in patients with colorectal cancer and type 2 diabetes mellitus / 中华医学杂志(英文版)

BACKGROUND@#Type 2 diabetes mellitus (T2DM) is an independent risk factor for colorectal cancer (CRC), and the patients with CRC and T2DM have worse survival. The human gut microbiota (GM) is linked to the development of CRC and T2DM, respectively. However, the GM characteristics in patients with CRC and T2DM remain unclear.@*METHODS@#We performed fecal metagenomic and targeted metabolomics studies on 36 samples from CRC patients with T2DM (DCRC group, n = 12), CRC patients without diabetes (CRC group, n = 12), and healthy controls (Health group, n = 12). We analyzed the fecal microbiomes, characterized the composition and function based on the metagenomics of DCRC patients, and detected the short-chain fatty acids (SCFAs) and bile acids (BAs) levels in all fecal samples. Finally, we performed a correlation analysis of the differential bacteria and metabolites between different groups.@*RESULTS@#Compared with the CRC group, LefSe analysis showed that there is a specific GM community in DCRC group, including an increased abundance of Eggerthella , Hungatella , Peptostreptococcus , and Parvimonas , and decreased Butyricicoccus , Lactobacillus , and Paraprevotella . The metabolomics analysis results revealed that the butyric acid level was lower but the deoxycholic acid and 12-keto-lithocholic acid levels were higher in the DCRC group than other groups ( P < 0.05). The correlation analysis showed that the dominant bacterial abundance in the DCRC group ( Parvimonas , Desulfurispora , Sebaldella , and Veillonellales , among others) was negatively correlated with butyric acid, hyodeoxycholic acid, ursodeoxycholic acid, glycochenodeoxycholic acid, chenodeoxycholic acid, cholic acid and glycocholate. However, the abundance of mostly inferior bacteria was positively correlated with these metabolic acid levels, including Faecalibacterium , Thermococci , and Cellulophaga .@*CONCLUSIONS@#Unique fecal microbiome signatures exist in CRC patients with T2DM compared to those with non-diabetic CRC. Alterations in GM composition and SCFAs and secondary BAs levels may promote CRC development.

Biotransformation differences of ginsenoside compound K mediated by the gut microbiota from diabetic patients and healthy subjects / 中国天然药物

Many natural products can be bio-converted by the gut microbiota to influence pertinent efficiency. Ginsenoside compound K (GCK) is a potential anti-type 2 diabetes (T2D) saponin, which is mainly bio-transformed into protopanaxadiol (PPD) by the gut microbiota. Studies have shown that the gut microbiota between diabetic patients and healthy subjects are significantly different. Herein, we aimed to characterize the biotransformation of GCK mediated by the gut microbiota from diabetic patients and healthy subjects. Based on 16S rRNA gene sequencing, the results indicated the bacterial profiles were considerably different between the two groups, especially Alistipes and Parabacteroides that increased in healthy subjects. The quantitative analysis of GCK and PPD showed that gut microbiota from the diabetic patients metabolized GCK slower than healthy subjects through liquid chromatography tandem mass spectrometry (LC-MS/MS). The selected strain A. finegoldii and P. merdae exhibited a different metabolic capability of GCK. In conclusion, the different biotransformation capacity for GCK may impact its anti-diabetic potency.

Analysis of factors associated with the structure of the gut microbial community in HIV/AIDS patients in some areas of Henan province / 中华流行病学杂志

Objective: To investigate the related factors associated with the structure of the gut microbial community in HIV infection/AIDS cases (HIV/AIDS) in Henan province. Methods: The convenience sampling method was used to select 122 cases who were receiving Antiviral Treatment (ART) or ART-naive in Henan. Whole blood and stool specimens were collected. Genomic DNA of stool samples was extracted, and the V3-V4 hypervariable regions of the 16S rRNA gene were sequenced using Illumina NovaSeq 6000 high-throughput sequencing system. The analysis was performed mainly at the genus level, and the 30 genera with the highest abundance were selected as a measure of the gut microbial community structure. The correlation between community structure and related factors was analyzed using redundancy analysis and Envfit function. Results: 122 cases were finally completed sequencing and analysis, the average BMI was (23.62±2.78) kg/m2 and the average age was (47±13) years. Among them, male accounted for 66.39% (81/122), and heterosexual transmission route constituted the largest ratio, accounting for 51.64% (63/122). 36 cases were treatment naive (29.51%, 36/122). The top five dominant genera of the total population (122 cases) were Prevotella, Roseburia, Megamonas, Bacteroides and Faecalibacterium and the top five dominant genera of the ART population (86 cases) were Prevotella, Megamonas, Bacteroides, Roseburia and Faecalibacterium. The top five dominant genera of the ART-naive population (36 cases) appeared as Prevotella, Faecalibacterium, Roseburia, Bacteroides and Megamonas. In the total population, ART (P<0.001) was the most significant factors of community structure. Other significant factors were: duration of diagnosis (P=0.009), viral load (P=0.022) and anti-HCV (P=0.018). ART was positively correlated with Megamonas and negatively correlated with Prevotella, Roseburia and Faecalibacterium, while the other three factors of duration of diagnosis, viral load and anti-HCV were positively correlated with Prevotella, Roseburia and Faecalibacterium and negatively correlated with Megamonas. In the ART-naive population, duration of diagnosis (P=0.003) were the factors significantly associated with community structure. Duration of diagnosis was positively correlated with Roseburia, Faecalibacterium, Megamonas and Prevotella and negatively correlated with Bacteroides. Conclusion: ART and duration of diagnosis were factors significantly associated with gut microbial community structure and had a significant impact on multiple high-abundance genera.

Association between obesity with the diversity and genus of gut microbiota in school-aged children / 中华流行病学杂志

Objective: To analyze the diversity differences of gut microbiota between school-aged obese children and normal-weight children and identify the characteristic flora in obese children to provide some evidence for the subsequent study of the following study-related mechanisms and the prevention and treatment of obesity in school-aged children. Methods: This study was based on a cohort established in a primary school in Jiading district, Shanghai, 2016. Sixty-three children, including 43 boys and 20 girls, who were obese during the three years from 2016 to 2018, were enrolled in the obesity group. Among children who were average weight for three years, a total of 63 were selected as the control group, with matching with the obese ones in a 1 to 1 way according to age, sex and class. The primary characteristics, diet status, breastfeeding, and other information of children were collected by questionnaire. Fecal samples of participants in both groups were collected, and 16S rDNA sequencing was performed. Operable taxon units clustering according to 97% similarity and species annotation were based on the quality-optimized sequences. The difference in the diversity and genius of gut microbiota among children in the obesity and control groups were analyzed. The α diversity indices, including Ace, Chao1, Shannon, and Simpson index, were calculated. The β diversity was presented based on unweighted Unifrac distance and weighted Unifrac space by principal coordinate analysis. The differences in β diversity between the two groups were compared by similarity analysis (ANOSIM).The differences in genus distribution between the two groups were selected by STAMP software. The association of obesity with the α diversity and genus with significant differences were analyzed by the generalized linear model (GLM). Results: The Ace and Chao1 index in the obesity group was significantly lower than those in the control group (The P values were 0.026 and 0.039, respectively). There was no significant difference in Shannon and Simpson index between the two groups (The P values were 0.879 and 0.922, respectively). The results of ANOSIM showed differences in gut microbiota between the two groups (R>0), but the group contribution was not significant (unweighted Unifrac distance: R=0.006, P=0.223; weighted Unifrac distance: R=0.010, P=0.134). Among the obese group, the relative abundance of Prevotella and Sarcina was highest in the endemic genus. The STAMP results showed that the relative lots of 15 genera were significantly different between the two groups (P<0.05). The results of GLM showed that, compared with the control group, the obesity group had a lower level of the relative abundance in Akkermansia muciniphila, while a higher level in Coprococcus_3, Ruminococcus, Agathobacter and Collinsella. After stratification by sex, the Chao1 index was also lower in the obese boys than that in the normal-weight boys. However, the obese girls only had a higher level in Coprococcus_3 than the ordinary weight girls. Conclusions: Compared with children with average weight, obese children had lower α diversity of gut microbiota and lower relative abundance of dominant probiotics but had a higher relative lot of genus associated with metabolic disorders, inflammation promotion, and metabolism rate reduction.

Analysis of intestinal microbial diversity in Leopoldamys edwardsi based on illumina sequencing technique / 中华预防医学杂志

To explore the composition and diversity of the intestinal microflora of Leopoldamys edwardsi in Hainan Island. In November 2019, DNA was extracted from fecal samples of 25 adult Leopoldamys edwardsi (14 males and 11 females) in Hainan Island at the Joint Laboratory of tropical infectious diseases of Hainan Medical College and Hong Kong University. Based on the IonS5TMXL sequencing platform, single-end sequencing (Single-End) was used to construct a small fragment library for single-end sequencing. Based on Reads shear filtration and OTUs clustering. The species annotation and abundance analysis of OTUs were carried out by using mothur method and SSUrRNA database, and further conducted α diversity and β diversity analysis. A total of 1481842 high quality sequences, belonging to 14 Phyla, 85 families and 186 Genera, were obtained from 25 intestinal excrement samples of Leopoldamys edwardsi. At the level of phyla classification, the main core biota of the Leopoldamys edwardsi contained Firmicutes (46.04%),Bacteroidetes (25.34%), Proteobacteria (17.09%), Tenericutes (7.38%) and Actinobacteria (1.67%), these five phyla account for 97.52% of all phyla. The ratio of Helicobacter which occupied the largest proportion at the genus level was 12.44%, followed by Lactobacillus (11.39%), Clostridium (6.19%),Mycoplasma (4.23%) and Flavonifractor (3.52%). High throughput sequencing analysis showed that the intestinal flora of Leopoldamys edwardsi in Hainan Island was complex and diverse, which had the significance of further research.

Evaluation of the Gastric Microbiome in Patients with Chronic Superficial Gastritis and Intestinal Metaplasia / 中国医学科学杂志(英文版)

Objective To evaluate the gastric microbiome in patients with chronic superficial gastritis (CSG) and intestinal metaplasia (IM) and investigate the influence of Helicobacter pylori (H. pylori) on the gastric microbiome. Methods Gastric mucosa tissue samples were collected from 54 patients with CSG and IM, and the patients were classified into the following four groups based on the state of H. pylori infection and histology: H. pylori-negative CSG (n=24), H. pylori-positive CSG (n=14), H. pylori-negative IM (n=11), and H. pylori-positive IM (n=5). The gastric microbiome was analyzed by 16S rRNA gene sequencing. Results H. pylori strongly influenced the bacterial abundance and diversity regardless of CSG and IM. In H. pylori-positive subjects, the bacterial abundance and diversity were significantly lower than in H. pylori-negative subjects. The H. pylori-negative groups had similar bacterial composition and bacterial abundance. The H. pylori-positive groups also had similar bacterial composition but different bacterial relative abundance. The relative abundance of Neisseria, Streptococcus, Rothia, and Veillonella were richer in the I-HP group than in G-HP group, especially Neisseria (t=175.1, P<0.001). Conclusions The gastric microbial abundance and diversity are lower in H. pylori- infected patients regardless of CSG and IM. Compared to H. pylori-positive CSG group and H. pylori-positive IM, the relative abundance of Neisseria, Streptococcus, Rothia, and Veillonella is higher in H. pylori-positive patients with IM than in H. pylori-positive patients with CSG, especially Neisseria.

Shotgun metagenome sequencing of Chinese gut microbiota: a review / 生物工程学报

The research on the relationship between gut microbiota and human health continues to be a hot topic in the field of life science. Culture independent 16S rRNA gene high-throughput sequencing is the current main research method. However, with the reduction of sequencing cost and the maturity of data analysis methods, shotgun metagenome sequencing is gradually becoming an important method for the study of gut microbiome due to its advantages of obtaining more information. With the support from the human microbiome project, 30 805 metagenome samples were sequenced in the United States. By searching NCBI PubMed and SRA databases, it was found that 72 studies collecting about 10 000 Chinese intestinal samples were used for metagenome sequencing. To date, only 56 studies were published, including 16 related to metabolic diseases, 16 related to infectious and immune diseases, and 12 related to cardiovascular and cerebrovascular diseases. The samples were mainly collected in Beijing, Guangzhou, Shanghai and other cosmopolitan cities, where great differences exist in sequencing platforms and methods. The outcome of most studies are based on correlation analysis, which has little practical value in guiding the diagnosis and treatment of clinical diseases. Standardizing sampling methods, sequencing platform and data analysis process, and carrying out multi center parallel research will contribute to data integration and comparative analysis. Moreover, insights into the functional verification and molecular mechanism by using the combination of transcriptomics, proteomics and culturomics will enable the gut microbiota research to better serve the clinical diagnosis and treatment.

Estimating Postmortem Interval Using Intestinal Microbiota Diversity Based on 16S rRNA High-throughput Sequencing Technology / 法医学杂志

OBJECTIVES@#To explore the correlation between intestinal microbiota and postmortem interval(PMI) in rats by using 16S rRNA high-throughput sequencing technology.@*METHODS@#Rats were killed by anesthesia and placed at 16 ℃, and DNA was extracted in caecum at 14 time points of 0, 1, 2, 3, 5, 7, 9, 12, 15, 18, 21, 24, 27 and 30 d after death. The 16S rRNA high-throughput sequencing technology was used to detect intestinal microbiota in rat cecal contents, and the results were used to analyze the rat intestinal microbiota diversity and differences.@*RESULTS@#The total number of intestinal microbial communities did not change significantly within 30 days after death, but the diversity showed an upward trend. A total of 119 bacterial communities were significantly changed at 13 time points after death. The models for PMI estimation were established by using partial least squares (PLS) regression at all time points, before 9 days and after 12 days, reaching an R2 of 0.795, 0.767 and 0.445, respectively; and the root mean square errors (RMSEs) were 6.57, 1.96 and 5.37 d, respectively.@*CONCLUSIONS@#Using 16S rRNA high-throughput sequencing technology, the composition and structure of intestinal microbiota changed significantly within 30 d after death. In addition, the established PLS regression model suggested that the PMI was highly correlated with intestinal microbiota composition, showing a certain time series change.

Investigación traslacional en microbioma (InTraMic): un área de interés común y creciente en el IMTIB, Hospital Italiano e Instituto Universitario / Translational research in microbiome (InTraMic): an area of common and growing interest at IMTIB, Hospital Italiano and Instituto Universitario

Se estima que aproximadamente 100 trillones de microorganismos (incluidos bacterias, virus y hongos) residen en el intestino humano adulto y que el total del material genético del microbioma es 100 veces superior al del genoma humano. Esta comunidad, conocida como microbioma se adquiere al momento del nacimiento a través de la flora comensal de la piel, vagina y heces de la madre y se mantiene relativamente estable a partir de los dos años desempeñando un papel crítico tanto en el estado de salud como en la enfermedad. El desarrollo de nuevas tecnologías, como los secuenciadores de próxima generación (NGS), permiten actualmente realizar un estudio mucho más preciso de ella que en décadas pasadas cuando se limitaba a su cultivo. Si bien esto ha llevado a un crecimiento exponencial en las publicaciones, los datos sobre las poblaciones Latinoamérica son casi inexistentes. La investigación traslacional en microbioma (InTraMic) es una de las líneas que se desarrollan en el Instituto de Medicina Traslacional e Ingeniería Biomédica (IMTIB). Esta se inició en 2018 con la línea de cáncer colorrectal (CCR) en una colaboración con el Colorectal Cancer Research Group del Leeds Institute of Medical Research en el proyecto Large bowel microbiome disease network: Creation of a proof of principle exemplar in colorectal cancer across three continents. A fines de 2019 se cumplió el objetivo de comprobar la factibilidad de la recolección, envío y análisis de muestras de MBF en 5 continentes, incluyendo muestras provenientes de la Argentina, Chile, India y Vietnam. Luego de haber participado de capacitaciones en Inglaterra, se ha cumplido con el objetivo de la etapa piloto, logrando efectivizar la recolección, envío y análisis metagenómico a partir de la secuenciación de la región V4 del ARNr 16S. En 2019, la línea de enfermedad de hígado graso no alcohólico se sumó a la InTraMic iniciando una caracterización piloto en el marco de una colaboración con el laboratorio Novartis. Los resultados de ese estudio, así como el de cáncer colorrectal, están siendo enviados a publicación. En 2020, con la incorporación de la línea de trasplante alogénico de células progenitoras hematopoyéticas, fue presentado un proyecto para un subsidio del CONICET que ha superado la primera etapa de evaluación. En el presente artículo se brinda una actualización sobre la caracterización taxonómica de microbioma y se describen las líneas de investigación en curso. (AU)

It is estimated that approximately 100 trillion microorganisms (including bacteria, viruses, and fungi) reside in the adult human intestine, and that the total genetic material of the microbiome is 100 times greater than that of the human genome. This community, known as the microbiome, is acquired at birth through the commensal flora of the mother's skin, vagina, and feces and remains relatively stable after two years, playing a critical role in both the state of health and in disease. The development of new technologies, such as next-generation sequencers (NGS), currently allow for a much more precise study of it than in past decades when it was limited to cultivation. Although this has led to exponential growth in publications, data on Latin American populations is almost non-existent. Translational research in microbiome (InTraMic) is one of the lines developed at the Instituto de Medicina Traslacional e Ingeniería Biomédica (IMTIB). This started in 2018 with the Colorectal Cancer Line (CRC) in a collaboration with the Colorectal Cancer Research Group of the Leeds Institute of Medical Research in the project "Large bowel microbiome disease network: Creation of a proof of principle exemplar in colorectal cancer across three continents". At the end of 2019, the objective of verifying the feasibility of collecting, sending and analyzing MBF samples on 5 continents, including samples from Argentina, Chile, India and Vietnam, was met. After having participated in training in England, the objective of the pilot stage has been met, achieving the collection, delivery and metagenomic analysis from the sequencing of the V4 region of the 16S rRNA. In 2019, the non-alcoholic fatty liver disease line joined InTraMic, initiating a pilot characterization in the framework of a collaboration with the Novartis laboratory. The results of that study, as well as that of colorectal cancer, are being published. In 2020, with the incorporation of the allogeneic hematopoietic stem cell transplantation line, a project was presented for a grant from the CONICET that has passed the first stage of evaluation. This article provides an update on the taxonomic characterization of the microbiome and describes the lines of ongoing research. (AU)

High-throughput sequencing analysis of intestinal flora diversity of two freshwater snails (Radix auricularia and Planorbella trivolvis) / 生物工程学报

Freshwater snail is an important biological group in aquatic ecosystem and an intermediate host of many parasites. Intestinal flora plays an important role in animal energy metabolism and resistance to pathogens. We analyzed the intestinal microbiota diversity of Radix auricularia (RA) and Planorbella trivolvis (PL) by 16S rRNA high-throughput sequencing. At the phylum level, RA had 23 phyla, including Proteobacteria (33.63%), Cyanobacteria (15.33%), Chloroflexi (13.95%), and Actinomycetes (12.99%). PL had 13 phyla, including Proteobacteria (54.88%), Bacteroidetes (28.49%), and Actinomycetes (7.65%). At the genus level, there were 445 genera in RA, including Pleurocapsa, Thiodictyon, Leptotrichia, and Nocardioides. There were 238 genera in PL, including Cloacibacterium, OM60NOR5_clade, Pseudomonas, and Rhodobacter. Ninety-three genera were the common core flora of the two snail species (all the samples were present), and 27 genera had an abundance greater than 0.5%. The structure of intestinal microbiota was significantly different between the two groups (P=0.027). We performed the functional prediction of intestinal microbiota using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt), and the results show that the KEGG functional composition of the intestinal flora of the two snails was similar, and the abundance of the amino acid metabolism, carbohydrate metabolism and membrane transport were large. In summary, the intestinal microbiota of the two snails was high in diversity and significantly different, but there were a large number of common core flora.

A new quantitative 16S rRNA amplicon sequencing method / 生物工程学报

In recent years, 16S rRNA amplicon sequencing technology has been widely used to study human gut microbiota and to detect unknown pathogens in clinical samples. However, its resolution to bacterial population can only reach the relative abundance of genus level, and different factors affect the final bacterial profile, such as sample concentrations, PCR cycle numbers and amplification primers. In order to solve these problems, we developed a quantitative 16S rRNA amplicon sequencing method by combining random tag and internal marker method. The new methods improved the accuracy of human gut microbiota, reduced the impact of experimental operation on the results, and improved the comparability between sequencing and other molecular biological methods.

Comparison of gut microbiotal compositional analysis of patients with irritable bowel syndrome through different bioinformatics pipelines / 北京大学学报(医学版)

OBJECTIVE@#To assess whether the same biological conclusion, diagnostic or curative effects regarding microbial composition of irritable bowel syndrome (IBS) patients could be reached through different bioinformatics pipelines, we used two common bioinformatics pipelines (Uparse V2.0 and Mothur V1.39.5)to analyze the same fecal microbial 16S rRNA high-throughput sequencing data.@*METHODS@#The two pipelines were used to analyze the diversity and richness of fecal microbial 16S rRNA high-throughput sequencing data of 27 samples, including 9 healthy controls (HC group), 9 diarrhea IBS patients before (IBS group) and after Rifaximin treatment (IBS-treatment, IBSt group). Analyses such as microbial diversity, principal co-ordinates analysis (PCoA), nonmetric multidimensional scaling (NMDS) and linear discriminant analysis effect size (LEfSe) were used to find out the microbial differences among HC group vs. IBS group and IBS group vs. IBSt group.@*RESULTS@#(1) Microbial composition comparison of the 27 samples in the two pipelines showed significant variations at both family and genera levels while no significant variations at phylum level; (2) There was no significant difference in the comparison of HC vs. IBS or IBS vs. IBSt (Uparse: HC vs. IBS, F=0.98, P=0.445; IBS vs. IBSt, F=0.47,P=0.926; Mothur: HC vs.IBS, F=0.82, P=0.646; IBS vs. IBSt, F=0.37, P=0.961). The Shannon index was significantly decreased in IBSt; (3) Both workshops distinguished the significantly enriched genera between HC and IBS groups. For example, Nitrosomonas and Paraprevotella increased while Pseudoalteromonadaceae and Anaerotruncus decreased in HC group through Uparse pipeline, nevertheless Roseburia 62 increased while Butyricicoccus and Moraxellaceae decreased in HC group through Mothur pipeline.Only Uparse pipeline could pick out significant genera between IBS and IBSt, such as Pseudobutyricibrio, Clostridiaceae 1 and Clostridiumsensustricto 1.@*CONCLUSION@#There were taxonomic and phylogenetic diversity differences between the two pipelines, Mothur can get more taxonomic details because the count number of each taxonomic level is higher. Both pipelines could distinguish the significantly enriched genera between HC and IBS groups, but Uparse was more capable to identity the difference between IBS and IBSt groups. To increase the reproducibility and reliability and to retain the consistency among similar studies, it is very important to consider the impact on different pipelines.

Changes in weight and body fat after use of tetracycline and Lactobacillus gasseri in rats

ABSTRACT Recent studies have shown a role of intestinal microbiota in obesity. The consumption of antibiotics in the last 70 years has led to changes in intestinal microbiota, which has led to weight gain and body fat accumulation. To evaluate the possibility of weight gain induced by antibiotics and the possible protective effect of probiotics, we divided 45 animals (Rattus norvegicus) into groups and administered the following treatments over two weeks: tetracycline, tetracycline + Lactobacillus gasseri, and NaCl. The animals were weighed over the course of 8 weeks, and at the end of the treatment period, they were measured and subjected to bioelectrical impedance analysis. The results show that the group receiving tetracycline alone had a higher body mass index (p=0.030), a greater Lee index (p=0.008), and a lower body water percentage than the control group, indicating a greater accumulation of body fat. The group receiving the probiotics with tetracycline presented similar results to the control group, indicating a possible protective effect of body fat accumulation in the group receiving tetracycline alone. The results show that tetracycline increased the concentration of body fat, and the use of probiotics was associated with an ability to protect the animals from the pro-obesity effect.

Translational research into gut microbiota: new horizons on obesity treatment: updated 2014

Obesity is currently a pandemic of worldwide proportions affecting millions of people. Recent studies have proposed the hypothesis that mechanisms not directly related to the human genome could be involved in the genesis of obesity, due to the fact that, when a population undergoes the same nutritional stress, not all individuals present weight gain related to the diet or become hyperglycemic. The human intestine is colonized by millions of bacteria which form the intestinal flora, known as gut flora. Studies show that lean and overweight human may present a difference in the composition of their intestinal flora; these studies suggest that the intestinal flora could be involved in the development of obesity. Several mechanisms explain the correlation between intestinal flora and obesity. The intestinal flora would increase the energetic extraction of non-digestible polysaccharides. In addition, the lipopolysaccharide from intestinal flora bacteria could trigger a chronic sub-clinical inflammatory process, leading to obesity and diabetes. Another mechanism through which the intestinal flora could lead to obesity would be through the regulation of genes of the host involved in energy storage and expenditure. In the past five years data coming from different sources established causal effects between intestinal microbiota and obesity/insulin resistance, and it is clear that this area will open new avenues of therapeutic to obesity, insulin resistance and DM2.

Metagenomic analysis of the gastric microbiota cultivable from a patient with gastritis concomitant with Barrett´s esophagus / Análisis metagenómico de la microbiota gástrica cultivable a partir de un paciente con gastritis concomitante con esófago de Barrett

Barrett’s esophagus is a distal metaplasia characterized by the transformation of squamous mucosa into columnar mucosa. This esophageal phenotype is a product not only of the chronic reflux of gastric acids, but also by microorganisms that colonize the oral cavity and stomach. Two classes of microbiota can be identified in Barrett’s esophagus; microbiota type I is associated with the normal esophagus and type II with an inflamed esophagus. The present study describes the gastric microbiota of a patient with antral gastritis concomitant with Barrett’s esophagus absent infection with Helicobacter pylori. Gastric biopsies were obtained following the protocol of Sydney and following ethical practices. The isolates were cultivated under microaerophilic conditions on Columbia Agar supplemented with IsoVitaleX™ and 7% sterile blood. Extracted DNA was sequenced using 454-GS and the results analyzed on the MG-RAST server. Gram negative isolates were found and bacteria resistant to levofloxacin, amoxicillin, tetracycline, erythromycin, and clarithromycin. The phyla Bacteroidetes, Firmicutes, Fusobacteria and Proteobacteria, the genus Bacteroides and the species group Bacteroides fragilis were most abundant. Functionally, the metabolism of carbohydrates, amino acids, and to a lesser extent, the metabolism of cofactors and vitamins were most dominant, and of which the enzymes β-glucosidase (EC 3.2.1.21), β-galactosidase (EC 3.2.1.23) and β-N-acetylhexosaminidase (EC 3.2.1.52) were most dominant. The findings of this study, because they are of only one case may probably suggest a possible pathogenic role, previously undescribed for Bacteroides fragilis, associated with human gastritis when concomitant esophageal pathology exists.

El esófago de Barrett es una metaplasia distal caracterizada por la transformación de la mucosa escamosa a mucosa columnar. Este fenotipo esofágico es producto no solo de la exposición crónica al reflujo de ácidos gástricos sino también a microbios colonizantes de la cavidad oral y del estómago. El esófago Barrett presenta 2 clases de microbiotas; la microbiota tipo I asociada con esófago normal y la tipo II a fenotipos esofágicos inflamatorios. En el presente estudio se describió la microbiota gástrica de una paciente con gastritis antral concomitante con esófago de Barrett sin infección por Helicobacter pylori y se obtuvieron biopsias gástricas siguiendo el protocolo de Sydney y estándares bioéticos. Los cultivos se hicieron en condiciones microaerofílicas en agar Columbia suplementados con isovitalex y sangre estéril al 7%. El ADN extraído fue sometido a secuenciación empleando 454 GS y las lecturas fueron analizadas en el servidor MG-RAST. Se obtuvieron aislamientos gram-negativos y resistentes a levofloxacina, amoxicilina, tetraciclina, eritromicina y claritromicina. Los Phylum Bacteroidetes, Firmicutes, Fusobacteria y Proteobacteria, el género Bacteroides y las especies de grupo Bacteroides fragilis fueron los más abundantes. Funcionalmente, el metabolismo de carbohidratos, aminoácidos y en menor grado el metabolismo de cofactores y vitaminas fueron los más dominantes; de los cuales las enzimas la β-glicosidasa (EC 3.2.1.21), β-galactosidasa (EC 3.2.1.23) y la β-N-acetilhexosaminidasa (EC 3.2.1.52) fueron las más dominantes. Estos resultados, por ser de un solo caso, solo podrían sugerir un posible papel patogénico no descrito para Bacterioides fragilis asociado con gastritis humana cuando existe patología esofágica concomitante.