Features of the effect of a probiotic, containing Lactobacillus and Bifidobacterium on the intestinal microbiota and clinical symptoms of irritable bowel syndrome

Background. One of the important links in the pathogenesis of irritable bowel syndrome (IBS) is a change in the composition of the microbiota, and therefore, the use of probiotics in complex therapy can be considered as a pathogenetic treatment of this functional disease. Aim. To study the effectiveness of probiotic use on the composition of the intestinal microbiota and the dynamics of symptoms in patients with IBS with predominance of diarrhea (IBS-D) or constipation (IBS-C). Materials and methods. 10 patients with IBS-D and 7 patients with IBS-C who took a probiotic for 28 days, which included: Lactobacillus acidophilus 1.25×109 CFU, Bifidobacterium lactis – 1.25×109 CFU, Lactobacillus paracasei – 1.25×109 CFU, Lactobacillus rhamnosus – 1.25×109 CFU. The dynamics of symptoms was assessed using the Gastrointestinal Symptom Rating Scale, and the composition of the microbiota before and after taking the probiotic was analyzed by sequencing 16S pRNA of stool samples. Results. In both groups, we found a statistically significant decrease in the level of Proteobacteria and an increase in Firmicutes. In patients with IBS-C, there was a decrease in Negativicutes, which, on the contrary, increased in patients with IBS-D. Shannon's diversity index in patients with IBS-C was statistically significantly lower than in patients with IBS-D 1.55 vs 2.74 (p=0.1). Against the background of the application, there was an increase in microbial diversity in patients with IBS-D, it increased to 3.01, and in patients with IBS-C to 2.68. Against the background of changes in the microbiota, there was a positive dynamics of disease symptoms against the background of taking probiotics. Conclusion. The results obtained reflect the positive effect of probiotics in patients with IBS-D and IBS-C, which makes it possible to clarify the role of microbiota in the development of IBS and recommend their use as part of complex therapy for this disease.