POS0613 THE ROLE OF MICROBIOTA IN DIFFERENT DISEASE STAGES OF SYSTEMIC SCLEROSIS: A POSSIBLE IMPACT IN GASTROINTESTINAL TRACT DISEASE ACTIVITY?

Background: Gastrointestinal tract (GIT) is affected in approximately 90% of systemic sclerosis (SSc) patients from the earliest disease stages. Microbiota has recently emerged as an important environmental factor in SSc pathogenesis. Objectives: to test differences in the taxa composition of the fecal microbiota of very early SSc (VEDOSS) and established SSc patients. Methods: Twenty-nine SSc patients classified according to the ACR/EULAR 2013 criteria (27 female, mean ± SD disease duration 13.1±9.2 years) and 21 VEDOSS patients (19 female, mean± SD disease duration 6.4±5.2 years) were consecutively enrolled. For each patient, demographic, clinical and laboratoristic data were recorded and stool samples were collected. GI involvement and quality of life were investigated with UCLA-Gastrointestinal Tract Questionnaire (GIT)2.0 and Short Form Health Survey-36 (SF36). Microbiota was assessed through 16S rRNA Next Generation Gene-Sequencing analysis. Results: We found a different fecal microbiota profile between SSc and VEDOSS. In particular, classes of Bacilli and Choriobacteria, orders of Desulfovibrionales and Lactobacillales, the family of Eggerthellaceae, the genera Enterococcus, Lactobacillus, Streptococcus, Sutterella and Uncultured-Rhodospirillales were statistically significant increased in SSc, while the class of Clostridia, the family of Oscillospiraceae and the order UCG-002 were statistically significant increased in VEDOSS (Figure 1). VEDOSS patients had significantly higher SF-36-physical component score than SSc, a trend for higher SF-36-mental component summary (MCS), while no difference in the UCLA-GIT2.0 score (Table 1). In SSc patients, we observed a significant positive association between the genus Uncultured-Rhodospirillates and MCS, and between both genera Lactobacillus and Uncultured-Rhodospirillates and UCLA-GIT 2.0 score. In VEDOSS we found a significant positive correlation between both Bacilli class and Lactobacillus genus and MCS. Conclusion: Our data show, for the first time, a different microbiota composition in SSc and VEDOSS patients. In particular, we observed an increased abundance of genus Lactobacillus in SSc patients. However, no significant differences in the UCLA GIT score between the two groups were observed, confirming that GI symptoms also affect VEDOSS patients. Both these findings could suggest that the increased Lactobacillus values in SSc patients should raise the suspicion of more severe GIT involvement. This may account for the poor result of a lactobacillus- based probiotic treatment, usually observed in literature. It is necessary to confirm these data on larger groups of patients in the two phases of the disease.