Genomic and clinical effects associated with a relaxation response mind-body intervention in patients with irritable bowel syndrome and inflammatory bowel disease

Abstract

Introduction: Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD) can profoundly affect quality of life and are influenced by stress and resiliency. The impact of mind-body interventions (MBIs) on IBS and IBD patients has not previously been examined.

Methods: Nineteen IBS and 29 IBD patients were enrolled in a 9-week relaxation response based mind-body group intervention (RR-MBI), focusing on elicitation of the RR and cognitive skill building. Symptom questionnaires and inflammatory markers were assessed pre- and post-intervention, and at short-term follow-up. Peripheral blood transcriptome analysis was performed to identify genomic correlates of the RR-MBI.

Results: Pain Catastrophizing Scale scores improved significantly post-intervention for IBD and at short-term follow-up for IBS and IBD. Trait Anxiety scores, IBS Quality of Life, IBS Symptom Severity Index, and IBD Questionnaire scores improved significantly post-intervention and at short-term follow-up for IBS and IBD, respectively. RR-MBI altered expression of more genes in IBD (1059 genes) than in IBS (119 genes). In IBD, reduced expression of RR-MBI response genes was most significantly linked to inflammatory response, cell growth, proliferation, and oxidative stress-related pathways. In IBS, cell cycle regulation and DNA damage related gene sets were significantly upregulated after RR-MBI. Interactive network analysis of RR-affected pathways identified TNF, AKT and NF-κB as top focus molecules in IBS, while in IBD kinases (e.g. MAPK, P38 MAPK), inflammation (e.g. VEGF-C, NF-κB) and cell cycle and proliferation (e.g. UBC, APP) related genes emerged as top focus molecules.

Conclusions: In this uncontrolled pilot study, participation in an RR-MBI was associated with improvements in disease-specific measures, trait anxiety, and pain catastrophizing in IBS and IBD patients. Moreover, observed gene expression changes suggest that NF-κB is a target focus molecule in both IBS and IBD-and that its regulation may contribute to counteracting the harmful effects of stress in both diseases. Larger, controlled studies are needed to confirm this preliminary finding.

Trial registration: ClinicalTrials.Gov NCT02136745.

Conflict of interest statement

Competing Interests: The authors have the following conflicts to report: Dr. Kuo consults for Genova Diagnostics, Furiex, and Given Imaging. Dr. Kuo receives funding from Given and Furiex for clinical trials, unrelated to this particular study. Dr. Macklin serves on the DSMBs for Lantheus Medical Imaging, Shire Human Genetic Therapies, and Civitas Therapeutics. Dr. Denninger receives support for unrelated investigator-initiated studies from Onyx Pharmaceuticals and Basis. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Figures

Fig 1. CONSORT Enrollment diagram.

Fig 2. Pain Catastrophizing Scale scores at each of the four time points in Irritable Bowel Syndrome (IBS, light bars, top) and Inflammatory Bowel Disease (IBD, dark bars, bottom).

*p

Fig 3. State-Trait Anxiety Inventory (STAI)—Trait scores at each of the four time points.

STAI—Trait scores at each of the four time points in Irritable Bowel Syndrome (IBS, light bars, top) and Inflammatory Bowel Disease (IBD, dark bars, bottom). (*p<0.05, **p<0.01).

Fig 4. Disease-specific quality of life and symptom measures at each of the four time points.

A) Irritable Bowel Syndrome Quality of Life (IBS-QOL) scores; lower scores indicate improvement. B) Irritable Bowel Syndrome Symptom Severity Index (IBS-SSI) scores; lower scores indicate improvement. C) Inflammatory Bowel Disease Questionnaire (IBD-Q) scores; higher scores indicate improvement. *p<0.05, **p<0.01, ***p<0.001.

Fig 5. Transcriptional differences between IBS and IBD patients at baseline, pre-intervention, shown by A) a heatmap of significantly differentially expressed genes, B) functional categories enrichment analysis, and C) pathways enrichment analysis.

A) Relative Gene expression difference between IBD and IBS for significantly differentially expressed genes are shown with a pseudocolor scale (-1 to 1) with red color denoting higher gene expression among IBD patients and green color denoting higher expression among IBS patients. The rows represent the genes and columns represent individual patients. A large fraction of differentially expressed genes were found to be upregulated in IBD patients at baseline relative to IBS patients. B) Selected top functional categories of differentially expressed genes. The Y–axis represent functional categories and X-axis-log transformed P value (i.e., a value of 2 represents a P value of. 01), C) Selected pathways of by differentially expressed genes. The Y—axis represent pathways and X-axis-log transformed P value.

Fig 6. Transcriptional changes and significantly affected pathways for IBS patients pre- to post-mind body intervention.

A) Heatmap of selected top differentially expressed genes identified by comparing pre- to post-mind body intervention transcriptional profiles. Gene expression is shown with a pseudocolor scale (-1 to 1) with red color denoting increased gene expression post-intervention and green color denoting decreased expression post-intervention. The rows represent the genes and columns represent individual subjects in IBS group. B) Top pathways of genes with altered expression among IBS and IBD patients. Pathway enrichment analysis was performed on differentially expressed genes and significance of effect on pathway was determined using Fisher’s Exact Test p value. Each bar represents a significantly enriched pathway. The p value is depicted as —log10 (p value) on primary X-axis.

Fig 7. Transcriptional changes and pathways modulated pre- to post-RR-MBI among IBD patients.

A) Heatmap of selected differently expressed genes identified by comparing pre- to post-mind body intervention transcriptional profiles of IBD patients. Gene expression is shown with a pseudocolor scale (-1 to 1) with red color denoting increased fold change in gene expression and green color denoting decrease. The rows represent the genes and columns represent individual subjects in IBD group. B) Venn Diagram depicting common genes between IBS and IBD. Only 13 genes were commonly altered between IBS and IBD. C) Top pathways significantly affected by differentially expressed genes in IBD group. The statistical significance of effect on pathways was calculated using Fisher’s Exact Test. The pathways with P value <. 05 were considered significantly effected. Each bar represents a significantly enriched pathway. The p value is depicted as —log10 (p value) on the x-axis.

Fig 8. Network representation of the biological functions significantly altered by 8-weeks of RR-MBI in IBD patients.

Networks shown: A) Cellular morphology and tissue development related genes with UBC, MAPK8, NF-κB and ERK1/2 as primary regulatory nodes; B) Genes involved in cell death, apoptosis and inflammation with UBC, APP and IRF7 as a critical regulatory node. We used the Ingenuity Pathways Analysis tool (IPA 8.0) to generate the networks of genes altered by RR-MBI in IBD patients and merged the major networks with obvious related functions. Each node represents a gene and each edge represent a molecular interaction. The intensity of the node color indicates the degree of upregulation (red) and downregulation (green), while white nodes indicate non-modified genes that may be affected in a non-transcriptional manner.

Fig 9. Identification of potential key genes responsible for delivering the beneficial effects of RR-MBI in IBD identified using Gene Set Enrichment Analysis and leading edge analysis.

A) Bar graph depicting the abundance of genes in significantly enriched geneset (S2 Fig). B) Heatmap of most abundant genes in IBD patients depicting the pattern of downregulation after the RR-MBI.