Effect of probiotic Lactobacillus reuteri on gastrointestinal microbiota modulation and on clinical symtoms n patients with SNAS allergy.

Systemic Nickel Allergy Syndrome (SNAS) is a pathological condition related to the ingestion of Ni with food and it is characterized by cutaneous reactions and/or gastrointestinal (GI) symptoms which shows after ingestion of Ni-containing foods (Falagiani et al., 2008; Gangemi et al., 2009) Clinical symptoms are typically: eczema, urticaria, itch, dyspeptic symptoms, such as nausea and/or vomiting, heartburn, bloating, chronic abdominal pain, diarrhoea and constipation (Falagiani et al., 2008). 382 The purpose of this study was evaluate the effect of the probiotic Lactobacillus reuteri DSM 17938 strain (NOOS S.r.l., Italy), on the intestinal microbial population of SNAS patients, inducing the reduction of severity and frequency of gastrointestinal symptomatology as well as allergic cutaneous symptoms rather than a low Ni diet alone. For these reasons, a prospective double-blind randomized placebo-controlled study was planned. Sixteen patients, all females, aged from 18 to 65 years, with clinical symptoms correlated to SNAS were enrolled. The clinical severity of both allergic cutaneous and gastroenterological symptoms was evaluated. All patients followed a specific diet, in order to reduce the daily intake of nickel, and they were randomly assigned to two groups (experimental and placebo). The duration of the whole intervention was of 6 weeks. Faecal samples from patients were collected before, during and after the intervention, stored at -80°C and analysed throughout a culture-independent approach. In order to characterize the bacterial diversity in human fecal samples, ribosomal DNA (rDNA) was extracted from fecal samples, subjected to PCR amplification, by using Lactobacillus specific primers for the V1 to V3 regions (Walter et al., 2001) and universal primers for V6 to V8 regions of 16S rDNA (Randazzo et al., 2002) and analyzed by PCR-DGGE (Muyzer et al., 1993). Moreover, the impact of symptoms on the quality of life of each patient, by a Visual Analogic Scale, the frequency of gastrointestinal symptoms, consistency of stools, according to the Bristol Stool scale, side-effects bowel habits and also stool frequency were investigated. Significant changes in the severity scoring index were recorded in patients who received the probiotic supplementation compared with patients who received placebo as well as a significant reduction in drug consumption (antihistamines, antisecretory) and a significant increase in well days. Moreover, SNAS patients, which received the probiotic supplementation, showed a significant improvement in cutaneous and GI symptoms. DGGE fingerprinting obtained using universal primers revealed quite stable profiles during the treatment while results obtained with Lactobacillus specific primers highlighted significant shift during the treatment with an increase in LAB population in samples of patients which received probiotic supplementation. Hence, our findings confirm that the L. reuteri supplementation could be proposed as a valid tool for the SNAS pathology treatment.