The effects of different diet treatments on the quality of life and some biomarkers in individuals with constipation predominant irritable bowel syndrome (İBS)

This study was planned and conducted in order to evaluate the effects of different constipation diets on the quality of life, constipation status, intestinal barrier integrity and microbiota in female individuals between the ages of 19-50 who were diagnosed with constipation-dominant irritabl bowel syndrome (IBS). 60 female volunteers with IBS, who met the inclusion criteria in the study, were divided into three different groups with the completed randomization method after giving information about the study; constipation diet was given to the first group (n: 21), the constipation diet rich in soluble fiber was given to the second group (n: 17) and the constipation diet with probiotic yogurt was given to the third group (n: 22) and they were followed for 8 weeks. With questioning the nutritional habits of the individuals, anthropometric measurements (body weight, height, waist-hip ratio, waist-height ratio, neck circumference), food consumption records, biochemical findings (fasting blood sugar, cholesterol, triglyceride, LDL cholesterol, CRP, zonulin) Constipation Quality of Life Scale (CQLS), Constipation Severity Scale (CSS) and Bristol stool scale were used at the beginning and at the end of the study. Additionally, at the beginning and end of the study, stool samples were taken from 5 individuals from each group for microbiota analysis. At the end of the study, it was observed an increase in the amount of fiber intake in the subjects in 3 groups (p>0,05) even though it was not significant. When the Bristol stool forms of the individuals were evaluated at the beginning and at the end of the study, the improvement in the stool form of the individuals in the 2nd and 3rd groups were more effective than the 1st group (p <0.05). At the end of the study, a statistically significant decrease was observed in the CQLS and CSS scores of the subjects in all 3 groups (p <0.05), therefore an increase on the quality of life was detected. According to the results of the unweighted beta diversity analysis; while a statistically significant increase was observed in individuals in the 1st and 2nd groups in terms of the bacterial diversity accumulated in their microbiota after diet therapy (p <0.05), no change was detected in the individuals in the 3rd group (p> 0.05). It was found that the Porphyromonadaceae genus can be a negative biomarker for dietary treatment rich in soluble fiber, and the Subdoligranulum genus can be a positive biomarker for the diet containing probiotic yogurt. It was found that all three types of medical nutrition therapy increase the quality of life of individuals and have a positive effect on the improvement of stool form. In conclusion, in this study, it was determined that constipation diet rich in soluble fiber or constipation diet with probiotic yogurt had positive effects on IBS symptoms, although no superiority was observed over each other. Randomized controlled studies with larger samples are needed in order to determine the short and long-term effects of all 3 dietary treatments on the microbiota of individuals.