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Association of symptoms with gastrointestinal microbiota in irritable bowel syndrome
Erja Malinen, Lotta Krogius-Kurikka, Anna Lyra, Janne Nikkilä, Anne Jääskeläinen, Teemu Rinttilä, Terttu Vilpponen-Salmela, Atte Johannes von Wright, Airi Palva
Erja Malinen, Lotta Krogius-Kurikka, Janne Nikkilä, Airi Palva, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland
Anna Lyra, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland; Danisco Sweeteners, Health and Nutrition, 02460 Kantvik, Finland
Anne Jääskeläinen, Department of Clinical Nutrition, Institute of Public Health and Clinical Nutrition, Faculty of Health Sciences, University of Eastern Finland, 70211 Kuopio, Finland
Teemu Rinttilä, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland; Alimetrics Ltd., Koskelontie 19 B, 02920 Espoo, Finland
Terttu Vilpponen-Salmela, Kuopio Harjula Hospital, 70101 Kuopio, Finland
Atte Johannes von Wright, Department of Biosciences, University of Eastern Finland, 70211 Kuopio, Finland
Author contributions: Malinen E, Krogius-Kurikka L, Jääskeläinen A, Vilpponen-Salmela T, von Wright AJ and Palva A designed the research protocol; Vilpponen-Salmela T recruited the patients; Jääskeläinen A organized the collection of IBDQ questionnaires and performed the primary data analysis of the questionnaires; Krogius-Kurikka L, Lyra A and Rinttilä T performed the experiments; Malinen E and Nikkilä J conducted the computational data analyses; Malinen E, Krogius-Kurikka L and Lyra A wrote the manuscript and all authors made corrections to and approved the final version.
Supported by The Finnish Funding Agency for Technology and Innovation (Tekes grant No. 40039/03), the Finnish Graduate School on Applied Biosciences and the Centre of Excellence on Microbial Food Safety Research, Academy of Finland
Correspondence to: Airi Palva, Professor, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, PO Box 66, 00014 Helsinki, Finland. airi.palva@helsinki.fi
Telephone: +358-9-19157058 Fax: +358-9-19157033
Received: March 5, 2010
Revised: May 5, 2010
Accepted: May 12, 2010
Published online: September 28, 2010
AIM: To investigate the correlations between self-reported symptoms of irritable bowel syndrome (IBS) and the gastrointestinal (GI) microbiota composition.
METHODS: Fecal samples were collected from a total of 44 subjects diagnosed with IBS. Their symptoms were monitored with a validated inflammatory bowel disease questionnaire adjusted for IBS patients. Thirteen quantitative real-time polymerase chain reaction assays were applied to evaluate the GI microbiota composition. Eubacteria and GI bacterial genera (Bifidobacterium, Lactobacillus and Veillonella), groups (Clostridium coccoides/Eubacterium rectale, Desulfovibrio desulfuricans) and distinct bacterial phylotypes [closest 16S rDNA sequence resemblance to species Bifidobacterium catenulatum, Clostridium cocleatum, Collinsella aerofaciens (C. aerofaciens), Coprococcus eutactus (C. eutactus), Ruminococcus torques and Streptococcus bovis] with a suspected association with IBS were quantified. Correlations between quantities or presence/absence data of selected bacterial groups or phylotypes and various IBS-related symptoms were investigated.
RESULTS: Associations were observed between subjects’ self-reported symptoms and the presence or quantities of certain GI bacteria. A Ruminococcus torques (R. torques)-like (94% similarity in 16S rRNA gene sequence) phylotype was associated with severity of bowel symptoms. Furthermore, among IBS subjects with R. torques 94% detected, the amounts of C. cocleatum 88%, C. aerofaciens-like and C. eutactus 97% phylotypes were significantly reduced. Interesting observations were also made concerning the effect of a subject’s weight on GI microbiota with regard to C. aerofaciens-like phylotype, Bifidobacterium spp. and Lactobacillus spp.
CONCLUSION: Bacteria seemingly affecting the symptom scores are unlikely to be the underlying cause or cure of IBS, but they may serve as biomarkers of the condition.
