Dr. Navarro-López said: “Our results suggest that administration of this mixture of probiotics, as adjuvant treatment, may be effective in reducing the SCORAD index and, subsequently, decreasing the use of steroids during atopic dermatitis flares.”
He added that the clinical response documented in the probiotic group was greater than that obtained with other probiotics tested previously and suggested that a greater effect may have been seen due to the longer length of treatment and the patients involved in this particular trial.
“Treatment longer than eight weeks might condition the positive effect of probiotic use, patients older than 1 year have a greater response to probiotics, patients with moderate to severe atopic dermatitis have a better response, and a mixture of probiotics has better beneficial effects than a single probiotic, especially when lactobacilli and bifidobacteria are included in the mixture,” he said.
“The final blend used in the study was selected on the basis of published results and internal unpublished data,” he added.
The physiology of gut microbiota in atopic derm
So how might gut microbiota be implicated in atopic dermatitis and probiotics exert their effects?
It has been suggested that there is an association between a disruption in intestinal barrier function and the origin of atopic dermatitis, mediated by immunological activation leading to a type 2 dominant inflammation, which would suggest that gut microbiota could play an important immunomodulatory role in the development of normal immune tolerance. A predominance of T helper two cells rather than T helper 1, causes an imbalance that might aggravate the pathogenesis of atopic dermatitis, increasing IgE and activating interleukins.
Low levels of Faecalibacterium prausnitzii and an associated reduction in short chain fatty acid production have been implicated in Crohn’s disease, and a recent analysis of the gut microbiota of patients with atopic dermatitis has shown an intraspecies compositional change in Faecalibacterium prausnitzii that reduces the number of high butyrate and propionate producers.
Butyrate and propionate are microbial-produced short-chain fatty acids with an anti-inflammatory role, and butyrate has been shown to be a key player in maintaining gut barrier integrity. Therefore, reduced levels in the microbiota of both butyrate and propionate producers may result in a pro-inflammatory state in the gut and a loss of barrier integrity.
This raises a potential role for probiotics as microbiota recovery players in atopic dermatitis, Dr Navarro-López said.
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