In the duodenum of patients with celiac disease, the expression of the human serine protease inhibitor elafin is decreased. The appearance of the probiotic Bifidobacterium longum NCC2705 in duodenal aspirates was associated with a concomitant increase in the concentration of a bacterial homologue of elafin called serpin in patients with either celiac disease or non-celiac gluten sensitivity.
Celiac disease is a chronic autoimmune enteropathy triggered by gluten ingestion. Non-celiac gluten sensitivity is an emerging symptom-based condition, triggered by the ingestion of wheat and related cereals, but in the absence of celiac disease or wheat allergy. The standard treatment of these 2 conditions is a gluten-free diet. However, adherence to a strict gluten-free diet is challenging due to accidental gluten intake.
In a previous mouse model of celiac disease, B. longum NCC2705 was shown to ameliorate gluten immunopathology through the production of serpin. However, its effects on humans have never been tested.
The current placebo-controlled, cross-over trial evaluated the safety and gastrointestinal tolerability of B. longum NCC2705 in patients with celiac disease who were following a gluten-free diet for ≥ 1 year (n=18) and participants with self-diagnosed non-celiac gluten sensitivity who were on a gluten-free diet for ≥6 weeks (n=20). After intake of the probiotics on the test day, B. longum NCC2705 was detected in duodenal aspirates in both groups. In parallel, the serpin concentration significantly increased by 36% compared to placebo (P=0.016).
No serious adverse events (AEs) were recorded. Other AEs and gastrointestinal tolerability parameter scores (nausea, flatulence, bowel sounds, abdominal cramping, diarrhoea, and vomiting) did not differ between probiotic and placebo groups.
The current study showed that the appearance of B. longum NCC2705 in duodenal aspirates was associated with a concomitant increase in serpin concentration. This provides a mechanistic basis for the potential use of this probiotic as an adjuvant treatment to gluten-free diet to protect from accidental gluten intake. Besides, this probiotic was well tolerated and safe for human consumption.
1. Otten B. Safety of Bifidobacterium longum NCC 2705 and production of its serpin in patients with celiac disease and non-celiac gluten sensitivity. UEG Week Virtual Symposium 2020, abstract OP174.