The Effect of Common Viral Inactivation Techniques on 16S rRNA Amplicon-Based Analysis of the Gut Microbiota

Research investigating the gut microbiome (GM) during a viral infection may necessitate inactivation of the fecal viral load. Here, we assess how common viral inactivation techniques affect 16S rRNA-based analysis of the gut microbiome. Five common viral inactivation methods were applied to cross-matched fecal samples from sixteen female CD-1 mice of the same GM background prior to fecal DNA extraction. The V4 region of the 16S rRNA gene was amplified and sequenced from extracted DNA. Treatment-dependent effects on DNA yield, genus-level taxonomic abundance, and alpha and beta diversity metrics were assessed. A sodium dodecyl sulfate (SDS)-based inactivation method and Holder pasteurization had no effect on measures of microbial richness, while two Buffer AVL-based inactivation methods resulted in a decrease in detected richness. SDS inactivation, Holder pasteurization, and the AVL-based inactivation methods had no effect on measures of alpha diversity within samples or beta diversity between samples. Fecal DNA extracted with TRIzol-treated samples failed to amplify and sequence, making it unsuitable for microbiome analysis. These results provide guidance in the 16S rRNA microbiome analysis of fecal samples requiring viral inactivation.

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Inconsistent Patterns of Microbial Diversity and Composition Between Highly Similar Sequencing Protocols: A Case Study With Reef-Building Corals

Frontiers in Microbiology ◽

10.3389/fmicb.2021.740932 ◽

2021 ◽

Vol 12 ◽

Author(s):

Hannah E. Epstein ◽

Alejandra Hernandez-Agreda ◽

Samuel Starko ◽

Julia K. Baum ◽

Rebecca Vega Thurber

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Beta Diversity ◽

Sequence Data ◽

Alpha Diversity ◽

Gene Profiling ◽

Rrna Gene ◽

Sequencing Platform ◽

Alpha And Beta Diversity ◽

Diversity Metrics

16S rRNA gene profiling (amplicon sequencing) is a popular technique for understanding host-associated and environmental microbial communities. Most protocols for sequencing amplicon libraries follow a standardized pipeline that can differ slightly depending on laboratory facility and user. Given that the same variable region of the 16S gene is targeted, it is generally accepted that sequencing output from differing protocols are comparable and this assumption underlies our ability to identify universal patterns in microbial dynamics through meta-analyses. However, discrepant results from a combined 16S rRNA gene dataset prepared by two labs whose protocols differed only in DNA polymerase and sequencing platform led us to scrutinize the outputs and challenge the idea of confidently combining them for standard microbiome analysis. Using technical replicates of reef-building coral samples from two species, Montipora aequituberculata and Porites lobata, we evaluated the consistency of alpha and beta diversity metrics between data resulting from these highly similar protocols. While we found minimal variation in alpha diversity between platform, significant differences were revealed with most beta diversity metrics, dependent on host species. These inconsistencies persisted following removal of low abundance taxa and when comparing across higher taxonomic levels, suggesting that bacterial community differences associated with sequencing protocol are likely to be context dependent and difficult to correct without extensive validation work. The results of this study encourage caution in the statistical comparison and interpretation of studies that combine rRNA gene sequence data from distinct protocols and point to a need for further work identifying mechanistic causes of these observed differences.

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Comparative analysis of microbiome of bladder cancer patients

10.21203/rs.2.23701/v1 ◽

2020 ◽

Author(s):

Ayesha Ishaq ◽

Saman Zahid ◽

Salma Mukhtar ◽

Muhammad Kamran Azim ◽

Saleem Akhtar ◽

...

Keyword(s):

Bladder Cancer ◽

16S Rrna ◽

Bacterial Diversity ◽

Cancer Patients ◽

Beta Diversity ◽

Control Sample ◽

Diagnostic Tools ◽

Rrna Gene ◽

Male And Female ◽

Alpha And Beta Diversity

Abstract Background: It has been studied that the urinary tract, which was once considered to be sterile retains a unique microbiome. The current study was performed to explore the microbiome of male and female cancerous bladder tissue, including 01 control sample and 09 cancer samples using 16S rRNA gene sequencing. In previous studies, the significance of microbiome has been found to be associated with the bladder cancer. For diversity analysis, V3-V4 regions of 16S rRNA were used for PCR and later sequencing was carried out through Illumina, Miseq platform. The metadata generated was analyzed on QIIME 1.9.1.Result: The bacterial diversity detected showed that five of the phyla; namely Proteobacteria (38.1%), Firmicutes (37.8%), Actinobacteria (5.9%), Thermi (4.9%) and Tenericutes (2.5%) were more abundant in all samples as compared to other phyla. The genera found in all samples were Enterobacter (18.3%), Bacillus (13.9%), Meiothermus (4.9%), Methylotenera (1.2%), Ralstonia (3.6%) and Streptocococcus (1.4%). Ralstonia and Streptococcus were absent in BLC 10 and BLC 2, respectively, while present in the rest. The results of alpha and beta diversity showed that female samples had more bacterial diversity and uniformity as compared to male samples. Conclusion: The present study used biopsy samples of newly diagnosed cancer patients without taking into account any treatment given to the cancer patients. Our analysis showed insignificant differences in alpha and beta diversity of male and female samples. The genus Meiothermus detected in this study was firstly reported in a bladder microbiome analysis. The data generated from such preliminary futuristic study can help in devising new diagnostic tools and therapies.

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Microbial community composition and diversity via 16S rRNA gene amplicons: evaluating the Illumina platform

10.1101/010058 ◽

2014 ◽

Cited By ~ 2

Author(s):

Lucas Sinclair ◽

Omneya Ahmed Osman ◽

Stefan Bertilsson ◽

Alexander Eiler

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Beta Diversity ◽

Sequence Data ◽

Soda Lakes ◽

Microbial Community Composition ◽

Rrna Gene ◽

Clustering Methods ◽

Illumina Platform ◽

Alpha And Beta Diversity

As new sequencing technologies become cheaper and older ones disappear, laboratories switch vendors and platforms. Validating the new setups is a crucial part of conducting rigorous scientific research. Here we report on the reliability and biases of performing bacterial 16S rRNA gene amplicon paired-end sequencing on the MiSeq Illumina platform. We designed a protocol using 50 barcode pairs to run samples in parallel and coded a pipeline to process the data. Sequencing the same sediment sample in 248 replicates as well as 70 samples from alkaline soda lakes, we evaluated the performance of the method with regards to estimates of alpha and beta diversity. Using different purification and DNA quantification procedures we always found up to 5-fold differences in the yield of sequences between individually barcodes samples. Using either a one-step or a two-step PCR preparation resulted in significantly different estimates in both alpha and beta diversity. Comparing with a previous method based on 454 pyrosequencing, we found that our Illumina protocol performed in a similar manner -- with the exception for evenness estimates where correspondence between the methods was low. We further quantified the data loss at every processing step eventually accumulating to 50\% of the raw reads. When evaluating different OTU clustering methods, we observed a stark contrast between the results of QIIME with default settings and the more recent UPARSE algorithm when it comes to the number of OTUs generated. Still, overall trends in alpha and beta diversity corresponded highly using both clustering methods. Our procedure performed well considering the precisions of alpha and beta diversity estimates, with insignificant effects of individual barcodes. Comparative analyses suggest that 454 and Illumina sequence data can be combined if the same PCR protocol and bioinformatic workflows are used for describing patterns in richness, beta-diversity and taxonomic composition. (version 1.1 resubmitted to PLOS one 2014-Sept-08)

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Choice of 16S ribosomal RNA primers affects the microbiome analysis in chicken ceca

Scientific Reports ◽

10.1038/s41598-021-91387-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nadia Darwish ◽

Jonathan Shao ◽

Lori L. Schreier ◽

Monika Proszkowiec-Weglarz

Keyword(s):

16S Rrna ◽

Dna Sequences ◽

Bacterial Communities ◽

Beta Diversity ◽

Taxonomic Composition ◽

Rrna Gene ◽

Unifrac Distance ◽

Variable Regions ◽

Alpha And Beta Diversity ◽

Predicted Function

AbstractWe evaluated the effect of applying different sets of 16S rRNA primers on bacterial composition, diversity, and predicted function in chicken ceca. Cecal contents from Ross 708 birds at 1, 3, and 5 weeks of age were collected for DNA isolation. Eight different primer pairs targeting different variable regions of the 16S rRNA gene were employed. DNA sequences were analyzed using open-source platform QIIME2 and the Greengenes database. PICRUSt2 was used to determine the predicted function of bacterial communities. Changes in bacterial relative abundance due to 16S primers were determined by GLMs. The average PCR amplicon size ranged from 315 bp (V3) to 769 bp (V4–V6). Alpha- and beta-diversity, taxonomic composition, and predicted functions were significantly affected by the primer choice. Beta diversity analysis based on Unweighted UniFrac distance matrix showed separation of microbiota with four different clusters of bacterial communities. Based on the alpha- and beta-diversity and taxonomic composition, variable regions V1–V3(1) and (2), and V3–V4 and V3–V5 were in most consensus. Our data strongly suggest that selection of particular sets of the 16S rRNA primers can impact microbiota analysis and interpretation of results in chicken as was shown previously for humans and other animal species.

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Evaluation of the gut microbiome in association with biological signatures of inflammation in murine polytrauma and shock

Scientific Reports ◽

10.1038/s41598-021-85897-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sandra A. Appiah ◽

Christine L. Foxx ◽

Dominik Langgartner ◽

Annette Palmer ◽

Cristian A. Zambrano ◽

...

Keyword(s):

Gut Microbiota ◽

Community Composition ◽

Gut Microbiome ◽

Beta Diversity ◽

Microbial Community Composition ◽

Alpha Diversity ◽

Global Changes ◽

Rrna Gene ◽

Alpha And Beta Diversity ◽

Increased Risk

AbstractSevere injuries are frequently accompanied by hemorrhagic shock and harbor an increased risk for complications. Local or systemic inflammation after trauma/hemorrhage may lead to a leaky intestinal epithelial barrier and subsequent translocation of gut microbiota, potentially worsening outcomes. To evaluate the extent with which trauma affects the gut microbiota composition, we performed a post hoc analysis of a murine model of polytrauma and hemorrhage. Four hours after injury, organs and plasma samples were collected, and the diversity and composition of the cecal microbiome were evaluated using 16S rRNA gene sequencing. Although cecal microbial alpha diversity and microbial community composition were not found to be different between experimental groups, norepinephrine support in shock animals resulted in increased alpha diversity, as indicated by higher numbers of distinct microbial features. We observed that the concentrations of proinflammatory mediators in plasma and intestinal tissue were associated with measures of microbial alpha and beta diversity and the presence of specific microbial drivers of inflammation, suggesting that the composition of the gut microbiome at the time of trauma, or shortly after trauma exposure, may play an important role in determining physiological outcomes. In conclusion, we found associations between measures of gut microbial alpha and beta diversity and the severity of systemic and local gut inflammation. Furthermore, our data suggest that four hours following injury is too early for development of global changes in the alpha diversity or community composition of the intestinal microbiome. Future investigations with increased temporal-spatial resolution are needed in order to fully elucidate the effects of trauma and shock on the gut microbiome, biological signatures of inflammation, and proximal and distal outcomes.

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Wild gut microbiomes reveal individuals, species, and location as drivers of variation in two critically endangered Hawaiian honeycreepers

PeerJ ◽

10.7717/peerj.12291 ◽

2021 ◽

Vol 9 ◽

pp. e12291

Author(s):

Maria S. Costantini ◽

Matthew C.I. Medeiros ◽

Lisa H. Crampton ◽

Floyd A. Reed

Keyword(s):

Gut Microbiome ◽

Beta Diversity ◽

Captive Breeding ◽

Critically Endangered ◽

Sampling Location ◽

Human Populations ◽

Rrna Gene ◽

Important Species ◽

Fecal Samples ◽

Hawaiian Honeycreepers

Background The gut microbiome of animals is an important component that has strong influence on the health, fitness, and behavior of its host. Most research in the microbiome field has focused on human populations and commercially important species. However, researchers are now considering the link between endangered species conservation and the microbiome. In Hawaiʻi, several threats (e.g., avian malaria and habitat loss) have caused widespread population declines of Hawaiian honeycreepers (subfamily: Carduelinae). These threats can have a significant effect on the avian gut microbiome and may even lead to disruption of microbial function. However, the gut microbiome of honeycreeper in the wild has yet to be explored. Methods We collected 13 and 42 fecal samples, respectively, from two critically endangered honeycreeper species, the ʻakikiki (Oreomystis bairdi) and the ʻakekeʻe (Loxops caeruleirostris). The 16S rRNA gene was sequenced and processed though a MOTHUR-based bioinformatics pipeline. Bacterial ASVs were identified using the DADA2 program and bacterial community analyses, including alpha and beta diversity measures, were conducted using R packages Phyloseq and vegan. Results A total of 8,958 bacterial ASVs were identified from the fecal samples. Intraspecific differences in the gut microbiome among individual birds explained most of the variation present in the dataset, however differences between species did exist. Both species had distinct microbiomes with minimal overlap in beta diversity. ‘Akikiki had a more diverse microbiome compared to ‘akekeʻe. Additionally, small but stastically significant differences in beta diversity also exist between sampling location and sexes in ʻakikiki. Conclusion ʻAkikiki and ʻakekeʻe are currently the focus of captive breeding efforts and plans to translocate the two species to other islands are underway. This baseline knowledge will help inform management decisions for these honeycreeper species in their native habitats, on other islands, and in captivity.

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Retinitis pigmentosa is associated with shifts in the gut microbiome

Scientific Reports ◽

10.1038/s41598-021-86052-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Oksana Kutsyr ◽

Lucía Maestre-Carballa ◽

Mónica Lluesma-Gomez ◽

Manuel Martinez-Garcia ◽

Nicolás Cuenca ◽

...

Keyword(s):

Retinitis Pigmentosa ◽

Gut Microbiome ◽

Functional Decline ◽

Retinal Disease ◽

Photoreceptor Cells ◽

Amplicon Sequencing ◽

Rrna Gene ◽

Sequencing Data ◽

Alpha And Beta Diversity ◽

Potential Biomarker

AbstractThe gut microbiome is known to influence the pathogenesis and progression of neurodegenerative diseases. However, there has been relatively little focus upon the implications of the gut microbiome in retinal diseases such as retinitis pigmentosa (RP). Here, we investigated changes in gut microbiome composition linked to RP, by assessing both retinal degeneration and gut microbiome in the rd10 mouse model of RP as compared to control C57BL/6J mice. In rd10 mice, retinal responsiveness to flashlight stimuli and visual acuity were deteriorated with respect to observed in age-matched control mice. This functional decline in dystrophic animals was accompanied by photoreceptor loss, morphologic anomalies in photoreceptor cells and retinal reactive gliosis. Furthermore, 16S rRNA gene amplicon sequencing data showed a microbial gut dysbiosis with differences in alpha and beta diversity at the genera, species and amplicon sequence variants (ASV) levels between dystrophic and control mice. Remarkably, four fairly common ASV in healthy gut microbiome belonging to Rikenella spp., Muribaculaceace spp., Prevotellaceae UCG-001 spp., and Bacilli spp. were absent in the gut microbiome of retinal disease mice, while Bacteroides caecimuris was significantly enriched in mice with RP. The results indicate that retinal degenerative changes in RP are linked to relevant gut microbiome changes. The findings suggest that microbiome shifting could be considered as potential biomarker and therapeutic target for retinal degenerative diseases.

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Effect of Bovine MFGM and LF in Infant Formula on Gut Microbiome and Metabolome at Four Months of Age

Current Developments in Nutrition ◽

10.1093/cdn/nzab027 ◽

2021 ◽

Author(s):

Maciej Chichlowski ◽

Nicholas Bokulich ◽

Cheryl L Harris ◽

Jennifer L Wampler ◽

Fei Li ◽

...

Keyword(s):

Infant Formula ◽

Beta Diversity ◽

Milk Fat ◽

Alpha Diversity ◽

Illumina Miseq ◽

Rrna Gene ◽

Term Infants ◽

Linear Discriminant ◽

Alpha And Beta Diversity ◽

Metabolite Profiles

Abstract Background Milk fat globule membrane (MFGM) and lactoferrin (LF) are human milk bioactive components demonstrated to support gastrointestinal (GI) and immune development. Significantly fewer diarrhea and respiratory-associated adverse events through 18 months of age were previously reported in healthy term infants fed a cow's milk-based infant formula with added source of bovine MFGM and bovine LF through 12 months of age. Objectives To compare microbiota and metabolite profiles in a subset of study participants. Methods Stool samples were collected at Baseline (10–14 days of age) and Day 120 (MFGM + LF: 26, Control: 33). Bacterial community profiling was performed via16S rRNA gene sequencing (Illumina MiSeq) and alpha and beta diversity were analyzed (QIIME 2). Differentially abundant taxa were determined using Linear discriminant analysis effect size (LefSE) and visualized (Metacoder). Untargeted stool metabolites were analyzed (HPLC/mass spectroscopy) and expressed as the fold-change between group means (Control: MFGM + LF ratio). Results Alpha diversity increased significantly in both groups from baseline to 4 months. Subtle group differences in beta diversity were demonstrated at 4 months (Jaccard distance; R2 = 0.01, P = 0.042). Specifically, Bacteroides uniformis and Bacteroides plebeius were more abundant in the MFGM + LF group at 4 months. Metabolite profile differences for MFGM + LF vs Control included: lower fecal medium chain fatty acids, deoxycarnitine, and glycochenodeoxycholate, and some higher fecal carbohydrates and steroids (P < 0.05). After applying multiple test correction, the differences in stool metabolomics were not significant. Conclusions Addition of bovine MFGM and LF in infant formula was associated with subtle differences in stool microbiome and metabolome by four months of age, including increased prevalence of Bacteroides species. Stool metabolite profiles may be consistent with altered microbial metabolism. Trial registration: https://clinicaltrials.gov/ct2/show/NCT02274883).

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The Fecal Bacterial Microbiota in Horses with Equine Recurrent Uveitis

Animals ◽

10.3390/ani11030745 ◽

2021 ◽

Vol 11 (3) ◽

pp. 745

Author(s):

Michelle Martin de Bustamante ◽

Diego Gomez ◽

Jennifer MacNicol ◽

Ralph Hamor ◽

Caryn Plummer

Keyword(s):

Beta Diversity ◽

High Throughput Sequencing ◽

Illumina Miseq ◽

Diversity Indices ◽

Rrna Gene ◽

Linear Discriminant ◽

Alpha And Beta Diversity ◽

Bacterial Microbiota ◽

Healthy Control ◽

Equine Recurrent Uveitis

The objective of this study was to describe and compare the fecal bacterial microbiota of horses with equine recurrent uveitis (ERU) and healthy horses using next-generation sequencing techniques. Fecal samples were collected from 15 client-owned horses previously diagnosed with ERU on complete ophthalmic examination. For each fecal sample obtained from a horse with ERU, a sample was collected from an environmentally matched healthy control with no evidence of ocular disease. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene. The relative abundance of predominant taxa, and alpha and beta diversity indices were calculated and compared between groups. The phyla Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria predominated in both ERU and control horses, accounting for greater than 60% of sequences. Based on linear discriminant analysis effect size (LEfSe), no taxa were found to be enriched in either group. No significant differences were observed in alpha and beta diversity indices between groups (p > 0.05 for all tests). Equine recurrent uveitis is not associated with alteration of the gastrointestinal bacterial microbiota when compared with healthy controls.

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Gut Microbiome in Psoriasis: An Updated Review

Pathogens ◽

10.3390/pathogens9060463 ◽

2020 ◽

Vol 9 (6) ◽

pp. 463

Author(s):

Mariusz Sikora ◽

Albert Stec ◽

Magdalena Chrabaszcz ◽

Aleksandra Knot ◽

Anna Waskiel-Burnat ◽

...

Keyword(s):

Gut Microbiome ◽

Beta Diversity ◽

Large Scale ◽

Skin Diseases ◽

Intestinal Barrier ◽

Alpha Diversity ◽

Current Data ◽

Intestinal Microbiome ◽

Microbial Composition ◽

Alpha And Beta Diversity

(1) Background: A growing body of evidence highlights that intestinal dysbiosis is associated with the development of psoriasis. The gut–skin axis is the novel concept of the interaction between skin diseases and microbiome through inflammatory mediators, metabolites and the intestinal barrier. The objective of this study was to synthesize current data on the gut microbial composition in psoriasis. (2) Methods: We conducted a systematic review of studies investigating intestinal microbiome in psoriasis, using the PRISMA checklist. We searched MEDLINE, EMBASE, and Web of Science databases for relevant published articles (2000–2020). (3) Results: All of the 10 retrieved studies reported alterations in the gut microbiome in patients with psoriasis. Eight studies assessed alpha- and beta-diversity. Four of them reported a lack of change in alpha-diversity, but all confirmed significant changes in beta-diversity. At the phylum-level, at least two or more studies reported a lower relative abundance of Bacteroidetes, and higher Firmicutes in psoriasis patients versus healthy controls. (4) Conclusions: There is a significant association between alterations in gut microbial composition and psoriasis; however, there is high heterogeneity between studies. More unified methodological standards in large-scale studies are needed to understand microbiota’s contribution to psoriasis pathogenesis and its modulation as a potential therapeutic strategy.

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