Table 2.
Summary of studies assessing the enteric virome in IBD patients.
| Study | Year | Patient cohort | Age group | Sample source | Number of patients | Number of controls | Method | Key findings |
|---|---|---|---|---|---|---|---|---|
| Lepage et al. | 2008 | CD | Adult | Colonic biopsies | 19 | 14 | Epifluorescence microscopy, transmission electron microscopy | ↑Bacteriophages detected in the mucosa from CD patients than from healthy individuals |
| Wagner et al. | 2013 | CD | Paediatric | Ileal and colonic biopsies, gut wash samples | 6, 3 | 8 | Viral metagenome – 454 pyrosequencing Roche GS-FLX Titanium | Differences in bacteriophage composition between CD patients and control individuals |
| Pérez-Brocal et al. | 2013 | CD | Adult | Faeces, ileum tissue | 11, 1 | 6 | Viral metagenome – 454 pyrosequencing Roche GS- FLX titanium plus | ↓ Diversity of viral and bacterial communities in CD samples compared with the control group ↑ Variability between the CD samples in both virome and microbiome |
| Wang et al. | 2015 | CD + UC | Adult | Colonic tissue (biopsy/surgery) | 10 | 5 | Viral metagenome – Illumina HiSeq 2000 sequencing platform | ↑ Viral sequences in CD
Difference in abundance and diversity within the virome between CD and control group |
| Norman et al. | 2015 | CD + UC | Adult | Faeces | UK Cohort (UC 21, CD 14) Chicago cohort (UC 17, CD 8) LA cohort (UC 22, CD 1) Boston cohort (UC 15, CD 20) | UK Cohort (HC 22) Chicago cohort (HC 24) LA cohort (HC 0) Boston cohort (HC 10) | Viral metagenome – Roche 454 (initial study) and Illumina MiSeq platform (in-depth analysis) | ↑ Viral richness and Caudovirales expansion in CD and UC
↓ Decreased bacterial richness and diversity in UC and CD Inverse correlation of Caudovirales with prevalent bacterial taxa in CD |
UC, ulcerative colitis; CD, Crohn’s disease; HC, Healthy controls.