Effectiveness and safety of fecal microbiota transplantation in patients with postinfectious irritable bowel syndrome

Objective — to study the clinical and microbiological efficacy, as well as the safety of fecal microbiota transplantation (FMT) in patients with postinfectious irritable bowel syndrome (PI  IBS).Materials and methods. The examinations involved 56 patients (35 women and 21 men aged 22 to 58 years (mean age 36 ± 12 years)) with PI  IBS with diarrhea. All patients underwent complex laboratory and instrumental examination, gastroduodenoscopy and colonoscopy with the segmental biopsy, tests of feces for calprotectin, bacteriological feces, intestinal microbiota (IM) at the level of the main microbial phylotypes by determination of Firmicutes, Bacteroidetes and Actinobacteria DNA in stool samples using quantitative polymerase chain reaction in real time. Depending on the performed treatment, all patients were randomized into 2 groups using a computer random number method in a ratio of 1 : 1. The patients of Group I (18 women, 10 men) were administered basic therapy (diet with fiber restriction, otilonium bromide and a multi‑component probiotic for 1 month), in the Group 2, each patient with PI IBS (20 women, 8 men) underwent a single FMT procedure by means of the introduction of fecal material from a healthy super‑donor into the cecum at the time of colonoscopy. The healthy super‑donor was tested in accordance with the European consensus on FMT. The clinical efficacy of treatment in each group of patients was evaluated after 2, 4, and 12 weeks according to the dynamics of abdominal symptoms, measured using the IBS‑SSS scale, fatigue reduction (FAS scale), and also a change in the quality of life (IBS‑QoL scale).Results. The severity of IBS‑SSS symptoms of IBS progressively decreased in both groups of patients, significantly decreasing compared to the baseline after 2 weeks (p < 0.01), and reaching a maximum after 12 weeks from the start of treatment. There were no significant differences in IBS‑SSS between the two groups after 2, 4, and 12 weeks, however, a decrease in abdominal pain and bloating, as well as improved stool in patients who underwent FMT, were more pronounced. The degree of severity of fatigue on the FAS scale significantly decreased after 4 weeks compared with the initial in both groups of patients (p < 0.05). The indicators of quality of life on the IBS‑QoL scale significantly exceeded the initial level only after 3 months. After 1 month after the start of treatment in both groups of patients, a significant decrease in the frequency of intestinal dysbiosis and its severity was revealed in comparison with the initial indicators (p < 0.05), which was significantly more frequently observed after FMT. 4 weeks after the start of treatment, a change in the ratio of the main microbial phylotypes was recorded in both groups of patients in the form of an increase in the relative number of Bacteroidetes and Firmicutes, as well as a decrease in the relative number of Actinobacteria, which were significant and more pronounced in the group of patients who underwent FMT.Conclusions. A single FMT for patients with PI  IBS had considerable effects on the intestinal microbiota, reducing the frequency and severity of dysbiotic disorders. Moreover, it was accompanied with the significant clinical improvement in most patients, which is comparable to the effectiveness of pharmacotherapy and was preserved for up to 3 months of observation.