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Updated: Jun 8, 2026

Perturbations of Circulating miRNAs in Irritable Bowel Syndrome Detected Using a Multiplexed High-throughput Gene Expression Platform
Published on: November 30, 2016
Association of symptoms with gastrointestinal microbiota in irritable bowel syndrome
Erja Malinen1, Lotta Krogius-Kurikka, Anna Lyra
1Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland.
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.
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