Influence of Bifidobacterium infantis 35624 on the clinical course of irritable bowel syndrome depending on the phenotype: results of a local non-interventional prospective epidemiological study IBS-Control

Abstract

Objective — to evaluate the clinical efficacy of B. infantis 35624 on the course of IBS depending on the phenotype.Materials and methods. The clinical study involved 1870 patients. From them, 1260 patients with a verified diagnosis of IBS according to Rome IV criteria (2016) were included for further follow‑up. Patients were divided into three groups depending on the phenotype: diarrhea predominant IBS (IBS‑D) — 522 patients, constipation predominant IBS (IBS‑C) — 376 patients, mixed IBS (IBS‑M) — 362 patients. All patients were prescribed a dietary supplement «Alflorex», which contains the original strain of B. infantis 35624 in a dosage > 109 bacteria, 1 capsule daily. The efficiency criteria included dynamic of bowel movement frequency, stool consistency according to the Bristol stool scale, an assessment of a pain syndrome and flatulence on a visual analog scale (VAS). Assessment of the symptoms severity in patients with IBS was performed by specialized questionnaire IBS‑SSI (Irritable Bowel Syndrome‑Symptom Severity Index).Results. After 8 weeks of treatment, absence of the pain was detected in 450 (86.2 %) patients with IBS‑D, in 296 (79.6 %) patients with IBS‑M and in 282 (75.0 %) patients with IBS‑C. The satisfaction of stool consistency and bowel movement was marked in 309 (59.2 %) patients with IBS‑D, in 166 (44.6 %) — patients with IBS‑M and in 93 (24.7 %) patients with IBS‑C after 4 weeks of the treatment. At the end of the 8th week, this index significantly improved in 420 (80.5 %) patients with IBS‑D, in 231 (62.1 %) patients with IBS‑M and in 184 (49.0 %) patients with IBS‑C. The greatest positive effect of B. infantis 35624 on the pain intensity was found in patients with IBS‑D after 8 weeks of treatment. It was confirmed by a reducing pain intensity in 2.4 times (p < 0.02) and in 1.9 times (p < 0.05) compared with patients with IBS‑C and IBS‑M, respectively. The patients with IBS‑D had a significant decrease in stool frequency in 1.4 times (p < 0.05) after the first treatment week. Reduction in the IBS severity (according to the IBS‑SSI questionnaire) was found in all groups of patients who received B. infantis 35624. However, after 4th treatment weeks, the fastest positive dynamics was found in patients with IBS‑D. It was a significant reduction in symptom severity in 2.0 times (p < 0.01) due to a decrease in bloating and heaviness in the abdomen, reduced pain intensity, days when the pain was appeared.Conclusions. The results of clinical study confirmed that during treatment with B. infantis 35624 the most positive dynamics of the IBS symptoms reduction was found in patients with IBS‑D. Based on patients’ evaluation, the normalization of the stool frequency and bowel movements with attenuation of pain intensity and flatulence took place regardless of IBS type.