Clinical and Microbiological Effect of a Multispecies Probiotic Supplementation in Celiac Patients With Persistent IBS-type Symptoms: A Randomized, Double-Blind, Placebo-controlled, Multicenter Trial

Abstract

Goals: The goals of this study were to evaluate the efficacy and safety of a probiotic mixture in patients with celiac disease (CD) with irritable bowel syndrome (IBS)-type symptoms despite a strict gluten-free diet (GFD).

Background: About 30% of patients with CD adherent to a GFD suffer from IBS-type symptoms; a possible cause resides in the imbalances of the intestinal microbiota in CD. Probiotics may represent a potential treatment.

Study: CD patients with IBS-type symptoms entered a prospective, double-blind, randomized placebo-controlled study. A 6-week treatment period was preceded by a 2-week run-in and followed by a 6-week follow-up phase. Clinical data were monitored throughout the study by validated questionnaires: IBS Severity Scoring System (IBS-SSS); Gastrointestinal Symptom Rating Scale (GSRS); Bristol Stool Form Scale (BSFS); and IBS Quality of Life Questionnaire (IBS-QOL). The fecal microbiota were assayed using plate counts and 16S rRNA gene-based analysis.

Results: In total, 109 patients were randomized to probiotics (n=54) or placebo (n=55). IBS-SSS and GSRS decreased significantly in probiotics, as compared with placebo [(-15.9%±14.8% vs. 8.2%±25.9%; P<0.001) and (-19.8%±16.6% vs. 12.9%±31.6%; P<0.001)], respectively. Treatment success was significantly higher in patients receiving probiotics, as compared with placebo (15.3% vs. 3.8%; P<0.04). Presumptive lactic acid bacteria, Staphylococcus and Bifidobacterium, increased in patients receiving probiotic treatment. No adverse events were reported.

Conclusions: A 6-week probiotic treatment is effective in improving the severity of IBS-type symptoms, in CD patients on strict GFD, and is associated with a modification of gut microbiota, characterized by an increase of bifidobacteria.

FIGURE 1

Study design. BSFS indicates Bristol Stool Form Scale; GSRS, Gastrointestinal Symptom Rating Scale; IBS-SSS, Irritable Bowel Syndrome Severity Scoring System; QOL, Quality of Life; R, randomization.

FIGURE 2

Flow diagram of patients in the trial from eligibility to the end of follow-up. GFD indicates gluten-free diet; TTG-IgA, tissue transglutaminase immunoglobulin-A.

FIGURE 3

Relative abundance of the most relevant metabolically active bacterial phyla found in feces of the fecal samples of celiac disease patients with irritable bowel syndrome at baseline (W2), after 6 weeks (W8) of treatment with probiotics or placebo, and at the end of follow-up (W14). NS indicates not significant; OTU, operational taxonomic unit; P, placebo; T, treated.

FIGURE 4

Metabolically active Bifidobacterium genus found in feces of the fecal samples of celiac disease patients with irritable bowel syndrome at baseline (W2), after 6 weeks (W8) of treatment with probiotics or placebo, and at the end of follow-up (W14). NS indicates not significant; OTU, operational taxonomic unit; P, placebo; T, treated.