Prevalence and temporal stability of selected clostridial groups in irritable bowel syndrome in relation to predominant faecal bacteria

Abstract

The differences in faecal bacterial population between irritable bowel syndrome (IBS) and control subjects have been reported in several studies. The aim of the present study was to compare the predominant and clostridial faecal microbiota of IBS subjects and healthy controls by applying denaturing gradient gel electrophoresis (DGGE) and a recently developed multiplexed and quantitative hybridization-based technique, transcript analysis with the aid of affinity capture (TRAC). According to the results, the studied clostridial groups (Clostridium histolyticum, Clostridium coccoides-Eubacterium rectale, Clostridium lituseburense and Clostridium leptum) represented the dominant faecal microbiota of most of the studied subjects, comprising altogether 29-87 % of the total bacteria as determined by the hybridized 16S rRNA. The C. coccoides-E. rectale group was the dominant subgroup of clostridia, contributing a mean of 43 % of the total bacteria in control subjects and 30 % (constipation type) to 50 % (diarrhoea type) in different IBS symptom category subjects. The proportion of the C. coccoides-E. rectale group was found to be significantly lower in the constipation-type IBS subjects than in the control subjects. DNA-based PCR-DGGE and RNA-based RT-PCR-DGGE analyses targeted to the predominant bacterial population showed considerable biodiversity as well as uniqueness of the microbiota in each subject, in both control and IBS subject groups. The RT-PCR-DGGE profiles of the IBS subjects further indicated higher instability of the bacterial population compared to the control subjects. The observations suggest that clostridial microbiota, in addition to the instability of the active predominant faecal bacterial population, may be involved in IBS. INTRODUCTIONThe composition of the resident intestinal microbiota varies between individuals, and the predominant population is fairly stable under normal conditions (Zoetendal et al., 1998; Harmsen et al., 2002a;Vanhoutte et al., 2004; Mättö et al., 2005). However, several factors, such as antibiotic therapy, ageing and disease, may cause disturbances in the intestinal balance. Transient disturbance of the intestinal microbiota during antibiotic therapy has been shown in several studies (Edlund & Nord, 2000; Donskey et al., 2003). Changes in the intestinal microbiota have also been suggested to occur in certain intestinal diseases and disorders, such as inflammatory bowel disease (IBD) (Seksik et al., 2003) and irritable bowel syndrome (IBS) (Madden & Hunter, 2002). IBS is an intestinal disorder that involves continuous or recurrent intestinal pain or discomfort that is relieved during defecation. In addition, IBS symptoms include bloating, altered stool frequency, form or passage, and passage of mucus (Thompson et al., 1999). The existence of abnormal colonic fermentation in IBS (King et al., 1998) and alleviation of IBS symptoms by eradication of small intestinal bacterial overgrowth by antibiotic therapy (Pimentel et al., 2000), suggest that the intestinal microbiota has...

Gastrointestinal microbiota in irritable bowel syndrome: present state and perspectives

“…The same IBS subjects that had previously shown temporal instability (Mättö et al, 2005) were readdressed by excluding those patients who had recently received antibiotics (Maukonen et al, 2006). The temporal variation of the GI microbiota was not higher in IBS patients according to the DNA-based DGGE profiles, while faecal RNA amplicons were more stable in the HCs.…”

“…Of the eight studies listed in Table 1, five analysed samples from the same Finnish IBS cohort with complementary methodologies: qualitative microbiota profiling (Maukonen et al, 2006;Mättö et al, 2005) was followed by targeted analyses using quantitative PCR (qPCR) assays that were specific to dominant genera and species (Malinen et al, 2005) and phylotypes with a putative association with IBS . To obtain a holistic assessment of the entire microbiota, 16S rDNA sequencing of clone libraries was performed on the selected fractions of all IBS subtypes (Kassinen et al, 2007) as well as on the entire GI microbiota of IBS-D patients and HCs ).…”

Dysbiosis of the Intestinal Microbiota in IBS

“…The main advantage is the possibility to gain a non-restricted overview and with sequencing, to able to design targeted primers and probes for applications based on PCR or hybridization. Greater temporal instability of the intestinal microbiota of IBS patients compared with that of healthy controls has been detected with RNA-based DGGE (Maukonen et al, 2006). Applying DNA-based DGGE on the same sample set did not show IBS related temporal variation (Maukonen et al, 2006), but variation due to antibiotic therapy was observed .…”

“…Greater temporal instability of the intestinal microbiota of IBS patients compared with that of healthy controls has been detected with RNA-based DGGE (Maukonen et al, 2006). Applying DNA-based DGGE on the same sample set did not show IBS related temporal variation (Maukonen et al, 2006), but variation due to antibiotic therapy was observed . The inter-individual variability has been assessed in two studies with contradictory results.…”

“…Aspects such as their absolute and relative abundance, prevalence and association to symptoms sub-types and perception have been studied. The sample set studied by Mättö et al (2005) and Maukonen et al (2006) was further studied using 20 quantitative real-time PCR (qPCR) assays covering approximately 300 bacterial species (27 IBS patients and 22 controls gave faecal samples at the first time-point; 21 IBS patients and 15 controls gave faecal samples at three time-points at three-month intervals) (Malinen et al, 2005). The Clostridium coccoides and Bifidobacterium catenulatum group assays detected more target bacteria in controls than in IBS patients when the results from the three different time-points were averaged and the IBS subjects analysed as a single group.…”