Effect of Bifidobacterium infantis NLS super strain in symptomatic coeliac disease patients on long-term gluten-free diet – an exploratory study

Bifidobacterium infantis NLS super strain (B. infantis NLS-SS) was previously shown to alleviate gastrointestinal symptoms in newly diagnosed coeliac disease (CD) patients consuming gluten. A high proportion of patients following a gluten-free diet experiences symptoms despite dietary compliance. The role of B. infantis in persistently symptomatic CD patients has not been explored. The aim of the study was to evaluate the effect of B. infantis NLS-SS on persistent gastrointestinal symptoms in patients with CD following a long-term GFD. We conducted a randomised, cross-over, double-blind, placebo-controlled trial in symptomatic adult CD patients on a GFD for at least two years. After one-week run-in, patients were randomised to B. infantis NLS-SS or placebo for 3 weeks with cross-over after a 2-week wash-out period. We estimated changes (Δ) in celiac symptom index (CSI) before and after treatment. Stool samples were collected for faecal microbiota analysis (16S rRNA sequencing). Gluten immunogenic peptide (GIP) excretion in stool and urine samples was measured at each study period. Eighteen patients were enrolled; six patients were excluded due violations in protocol. For patients with the highest clinical burden, CD symptoms were lower in probiotic than in placebo treatment (P=0.046). B. infantis and placebo treated groups had different microbiota profiles as assessed by beta diversity clustering. In probiotic treated groups, we observed an increase in abundance of B. infantis. Treatment with B. infantis was associated with decreased abundance of Ruminococcus sp. and Bifidobacterium adolescentis. GIP excretion in stools and urine was similar at each treatment period. There were no differences in adverse effects between the two groups. B. infantis NLS-SS improves specific CD symptoms in a subset of highly symptomatic treated patients (GFD). This is associated with a shift in stool microbiota profile. Larger studies are needed to confirm these findings. ClinicalTrials.gov: NCT03271138.