Probiotics modulate the immune response in children suffering from coeliac disease (CD) by reducing the pro- inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha), according to a recent double-blind placebo-controlled trial. However, in this study the effects only lasted during active treatment, suggesting ongoing probiotic treatment may be required for children suffering immune-related gastrointestinal disorders.
As gluten can cause a dysregulated immune response leading to intestinal mucosal injury, intestinal permeability and malabsorption, CD is treated with a gluten free diet (GFD). However, studies have shown that gluten is not the only environmental factor in CD. The gut microbiota play a role in modulating the immune response through constant interplay with the mucosal immune system, and studies have shown that a dysbiotic gut may actually enhance the inflammatory response and damage caused by gluten.
In the recent study, 49 children on a GFD diet were randomised into two groups, with the treatment group receiving 2 billion CFUs of Bifidobacteria breve for three months. TNF-alpha levels were significantly reduced at the end of the intervention period, however levels increased again on follow-up, three months after treatment ceased, while still on the GFD. Therefore, a GFD diet alone only partially normalises the common imbalances of low Bifidobacterium spp. and high Bacteroides spp. seen in CD sufferers and may not modulate the inflammatory immune responses.
These findings are supported in an earlier 2014 double-blind randomised placebo-controlled study in which Bifidobacterium longum (1 billion CFUs) given to 33 children on a GFD decreased peripheral CD3+ T lymphocytes and TNF-alpha levels. Additionally, it rebalanced gut microbiota composition by increasing bifidobacteria counts and reducing the potentially pathogenic and pro-inflammatory bacteria Bacteroides fragilis.
Due to the disturbed microbiota composition of CD sufferers, the difficulty in adhering strictly to a GFD and the lack of a positive effect on TNF-alpha while only on the GFD, these studies suggest that successful treatment of CD may require constant probiotic therapy to modulate inappropriate immune responses and decrease gluten toxicity in children.
- Klemenak M, Dolinsek J, Langerholc T, et al. Administration of Bifidobacterium breve decreases the production of TNF-alpha in children with celiac disease. Dig Dis Sci 2015, July 2 [Epub ahead of print]. [Abstract]
- Olivares M, Castillejo G, Varea V, et al. Double-blind, randomised, placebo-controlled intervention trial to evaluate the effects of Bifidobacterium longum cect 7347 in children with newly diagnosed coeliac disease. Br J Nutr 2014;112(1):30-40. [Full text]