Foundry120 atlas

Associations between host gene expression, the mucosal microbiome, and clinical outcome in the pelvic pouch of patients with inflammatory bowel disease.

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Dataset overview

Participants 205
Samples 255
Reuse readiness 8.9/10 evidence-backed score

Associations between host gene expression, the mucosal microbiome, and clinical outcome in the pelvic pouch of patients with inflammatory bowel disease.

Abstract

<h4>Background</h4>Pouchitis is common after ileal pouch-anal anastomosis (IPAA) surgery for ulcerative colitis (UC). Similar to inflammatory bowel disease (IBD), both host genetics and the microbiota are implicated in its pathogenesis. We use the IPAA model of IBD to associate mucosal host gene expression with mucosal microbiomes and clinical outcomes. We analyze host transcriptomic data and 16S rRNA gene sequencing data from paired biopsies from IPAA patients with UC and familial adenomatous polyposis. To achieve power for a genome-wide microbiome-transcriptome association study, we use principal component analysis for transcript and clade reduction, and identify significant co-variation between clades and transcripts.<h4>Results</h4>Host transcripts co-vary primarily with biopsy location and inflammation, while microbes co-vary primarily with antibiotic use. Transcript-microbe associations are surprisingly modest, but the most strongly microbially-associated host transcript pattern is enriched for complement cascade genes and for the interleukin-12 pathway. Activation of these host processes is inversely correlated with Sutterella, Akkermansia, Bifidobacteria, and Roseburia abundance, and positively correlated with Escherichia abundance.<h4>Conclusions</h4>This study quantifies the effects of inflammation, antibiotic use, and biopsy location upon the microbiome and host transcriptome during pouchitis. Understanding these effects is essential for basic biological insights as well as for well-designed and adequately-powered studies. Additionally, our study provides a method for profiling host-microbe interactions with appropriate statistical power using high-throughput sequencing, and suggests that cross-sectional changes in gut epithelial transcription are not a major component of the host-microbiome regulatory interface during pouchitis.

Study facts

Organism
Homo sapiens
Platform
Illumina MiSeq v2
Age group
adult
Disease groups
Anatomical sites

Data availability

  • Analysis code

Strengths & limitations for reuse

Strengths

  • Raw reads are advertised
  • Feature/OTU tables are advertised
  • Taxonomic tables are advertised
  • Analysis code is available
  • Participant-to-sample mapping is available
  • Participant counts are documented
  • Sample counts are documented
Extraction evidence & provenance

Each extracted field is shown with the source excerpt and location used to resolve it.

Assay

FieldValueEvidence
assay.paired_end True
generating paired-end reads of 175 bp in each direction.

Section Methods—16S profiling and sequencing, offset 75200

assay.platform Illumina MiSeq v2
Sequencing was performed on the Illumina MiSeq v2 platform

Section Methods—16S profiling and sequencing, offset 75000

assay.primers_reported True
Primers: 515 F [GTGCCAGCMGCCGCGGTAA] and 806R [GGACTACHVGGGTWTCTAAT].

Section Methods—16S profiling and sequencing, offset 74200

assay.read_depth_reported 29914
A mean sequence depth of 29,914 sequences/sample was obtained

Section Methods—Bioinformatic processing of sequences, offset 77300

assay.read_length 175
generating paired-end reads of 175 bp in each direction.

Section Methods—16S profiling and sequencing, offset 75200

assay.sequencing_type amplicon_16s
The 16S gene dataset consists of Illumina MiSeq sequences targeting the V4 variable region.

Section Methods—16S profiling and sequencing, offset 69000

assay.target_region V4
Illumina MiSeq sequences targeting the V4 variable region.

Section Methods—16S profiling and sequencing, offset 73500

Cohort

FieldValueEvidence
cohort.age_group adult
The cohort consisted of 265 patients (51% women) aged between 18 and 78 years

Section Results, offset 6200

cohort.disease_activity_metadata_available True
to numerically score inflammation, the severity of objective traits was graded

Section Methods—Patient cohort, offset 58000

cohort.study_design cross_sectional
a large, metadata-rich, cross-sectional cohort

Section Results, offset 4800

cohort.total_participants 205
we analyzed 205 IPAA patients with biopsies collected from the pouch and afferent limb

Section study.description, offset —

cohort.treatment_exposure_documented True
For this cohort, antibiotic use was reported as ‘true’ if patients had taken antibiotics in the 30 days prior to biopsy collections.

Section Methods—Patient cohort, offset 62000

cohort.treatment_response_metadata_available True
Acute Pouchitis (AP) based on historical or current documentation of inflammation of the pouch resolving after a single course of antibiotics

Section Methods—Patient cohort, offset 34300

Data_Assets

FieldValueEvidence
data_assets.analysis_code True
Input files used for MaAsLin are available from [72].

Section Using multivariate analysis with linear modeling to model host/microbe metadata associations, offset 89000

data_assets.feature_or_otu_table True
this pipeline picks OTUs using a reference-based method and constructs an OTU table

Section Methods—Bioinformatic processing of sequences, offset 63400

data_assets.open_access True
"isOpenAccess": "Y"

Section Publication metadata, offset —

data_assets.pipeline_or_tool_versions True
a data curation pipeline implemented in QIIME 1.5.0 as pick_reference_otus.py

Section Methods—Bioinformatic processing of sequences, offset 72400

data_assets.qc_or_negative_controls_reported True
The resulting OTU tables are checked for mislabeling and contamination

Section Methods—Bioinformatic processing of sequences, offset 63500

data_assets.raw_reads True
16S sequence data for this project have been filtered to remove human sequences and are publicly available

Section Data availability, offset 73000

data_assets.sample_metadata True
Metadata are available at [ 74 ].

Section Data availability, offset 81400

data_assets.taxonomic_table True
Taxonomy is assigned using the Greengenes predefined taxonomy map

Section Methods—Bioinformatic processing of sequences, offset 72700

Specimens

FieldValueEvidence
specimens.body_site pouch and afferent limb
with biopsies collected from the pouch and afferent limb

Section study.description, offset —

specimens.inflamed_status_available True
the inflammation score was defined as the sum of these traits

Section Methods—Patient cohort, offset 58000

specimens.longitudinal_sampling False
a large, metadata-rich, cross-sectional cohort

Section Results, offset 4800

specimens.number_of_samples 255
from a total of 255 samples representing 204 individuals

Section Results, offset 6500

specimens.participant_to_sample_mapping_available True
255 samples representing 204 individuals; these comprised 196 PPI samples and 59 pouch samples.

Section Results, offset 6500

specimens.sample_type mucosal_biopsy
Tissue biopsies were obtained from the mid-portion of the pouch and the PPI during pouchoscopy.

Section Methods—Sample collection, offset 64000