Parasitology Research

, Volume 106, Issue 5, pp 1033–1038 | Cite as

Irritable bowel syndrome: is it associated with genotypes of Blastocystis hominis

  • Javed YakoobEmail author
  • Wasim Jafri
  • Mohammad Asim Beg
  • Zaigham Abbas
  • Shagufta Naz
  • Muhammad Islam
  • Rustam Khan
Original Paper


Blastocystis hominis is the most common intestinal parasite in humans. An extensive genetic variability has been described recently in B. hominis isolates. The aim of this study was to analyze genotypes of B. hominis isolates obtained from the healthy individuals and patients with irritable bowel syndrome-diarrhea (IBS-D). The patients with IBS-D were enrolled from gastroenterology outpatient department at the Aga Khan University Hospital. History and physical examination was done. Stool microscopy, culture, and polymerase chain reaction for B. hominis genotyping were carried out. The study included 158 patients with IBS-D, mean age 41 ± 15, age range 16–83 years, and male/female ratio of 109:49. One hundred fifty-seven (49.8%) were taken as healthy control. The dominant B. hominis genotypes were genotype 1 in 87 (65%) and type 3 in 49 (37%). In IBS-D, genotype 1 was present in 75 (86%; P < 0.001) compared to 12 (14%) in controls while type 3 was present in 23 (47%) compared to 26 (53%) in controls (P < 0.001), respectively. Infection with single genotype of B. hominis was present in 70 (73%) with IBS-D and in 26 (27%) in control group while with multiple genotypes in 25 (64%) in IBS-D and 14 (36%) in control group (P = 0.30), respectively. Majority of our patients had typeable B. hominis infection. The genotype of B. hominis in IBS-D was type 1 while in control genotype 3 was predominant.


Irritable Bowel Syndrome Ascaris Lumbricoides Blastocystis Infection Fecal Smear Stool Microscopy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This study was supported by a grant from the Higher Educational Commission of Pakistan Project no. 20-774 to JY. We are grateful to the staff of the Juma Research Laboratory for their help during the completion of this work.

Conflict of interests

The authors declare that they have no conflict of interest.

Ethical standards

Formal ethics approval was granted by the Ethics Review Committee of the institution for this study.


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Javed Yakoob
    • 1
    • 4
    Email author
  • Wasim Jafri
    • 1
  • Mohammad Asim Beg
    • 2
  • Zaigham Abbas
    • 1
  • Shagufta Naz
    • 1
  • Muhammad Islam
    • 3
  • Rustam Khan
    • 1
  1. 1.Department of MedicineThe Aga Khan UniversityKarachiPakistan
  2. 2.Department of Pathology and MicrobiologyThe Aga Khan UniversityKarachiPakistan
  3. 3.Department of Medicine and Community Health SciencesThe Aga Khan UniversityKarachiPakistan
  4. 4.Department of MedicineThe Aga Khan University HospitalKarachiPakistan

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