Does Intestinal microflora play a role in the symptom scores and life quality of people with Coeliac disease?

An online survey, designed on Survey Monkey software, has been sent via the NSW Coeliac Disease Association e-mail database to small bowel biopsy confirmed Coeliac Disease members residing in the Sydney metropolitan area. The questionnaire elicited information thought to be associated with alterations in gastrointestinal microflora, e.g. birth methods, infant feeding practice, medication use and current dietary practice, and on lifestyle. A questionnaire to assess gastrointestinal and general symptoms was also be included in the online survey. Of those who have responded to the questionnaire, 50 people will be invited to participate in a randomised controlled trial (RCT). An interview will be conducted with the trial participants where the protocol will be explained to them. The participants will be asked to have a blood test for pre trial safety monitoring, this test will include a Full Blood Count, Liver and Renal function assay. The participants will be given a collection kit and asked to provide a stool and urine sample later in the privacy of their home for DNA faecal microbial analysis by Metametrix Laboratories. This group will then be randomised by age and sex into two groups: those receiving a probiotic supplement containing 450 billion colony forming units of a composite of lactobacillus spp, bifiodbacteria spp, and streptococcus thermophilus (CDP+, n=25), and those receiving placebo (CDP-, n=25). The supplement will be once taken daily via the oral route. Supplement duration will be twelve weeks. The placebo will be a taste and visually identical powder of maltose. At the end of the trial another stool and urine sample will be collected and participants will be required to complete the questionnaire again. Post clincial trial blood saftey monitoring tests will be repeated. All participants will have their test results forwarded to their general practitioner for their records. Stool samples, urine samples and answers to the questionnaires pre- and post-supplementation will be compared for each participant to establish links between supplementation, microflora and symptom scores. Comparisons will be made between the CDP+ and CDP- groups, and data from healthy, non-CD people (data already held by the laboratory). Data Analysis; The pilot study has shown larger counts of gram positive bacteria in CD subjects compared to controls. Research testing the GI microflora in chronic fatigue patients has also shown an increase in gram positive bacteria compared to controls (25). The ratio of gram negative to gram positive bacteria has therefore been chosen as a suitable primary outcome measure. A 1-tailed independent group t-test on the change in the logarithms of the ratio of gram negative to gram positive organisms was deemed to be an appropriate test of the outcome. The sample size was estimated with PASS 2008. The data used were the mean of the ln(gram negative/gram positive) from the pilot study (CD group, n=30) and the mean of the laboratory data of healthy people (control group, n=117). In the CD group ln(gram negative/gram positive) was 1.97 with a standard deviation of 3.0, whereas in the control group the ln(gram negative/gram positive) was 6.85. It was estimated that sample sizes of 19 per group have 80% power (1-beta) to detect a difference between groups in a mean change of 2.5 with standard deviations of the changes of 3.0 in each group at alpha=0.05 (1-tailed). This would occur if there were a mean increase of 2.5 from 2.0 to 4.5 in the treatment group and no change in the placebo group. It is thought that the improvement in intestinal microflora half-way between the CD pilot group and the control group is achievable in twelve weeks of supplementation. For the trial 50 people with CD will be recruited, 25 in each arm, to allow for drop-outs in each group. A statistician will be consulted for the data analysis. Anticipated outcomes and significance It is anticipated that statistically significant abnormalities in the levels of bacteria will be found in the intestines of the CD subjects. Therapeutic intervention using competitive inhibition with probiotic strains of bacteria is thought to result in improvements in both subjective symptom scores and faecal microflora. Reduction of any associated symptoms and/or co-morbidity, it is hoped, will enhance the health and quality of life in individuals affected by CD.