P093 Probiotic strains Lactobacillus plantarum and Saccharomyces boulardii influence the fibrotic responses of human intestinal subepithelial myofibroblasts.

Tarapatzi, G.(1);Filidou, E.(1);Kandilogiannakis, L.(1);Spathakis, M.(1);Arvanitidis, K.(1);Kotzampassi , K.(2);Kolios, G.(1);Vradelis, S.(3);

(1)Laboratory of Pharmacology- Faculty of Medicine, Democritus University of Thrace- Alexandroupolis, Alexandroupolis, Greece;(2)Department of Surgery, Aristotle University of Thessaloniki- AHEPA Hospital, Thessaloniki, Greece;(3)University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece;

Background

The strains Lactobacillus plantarum and Saccharomyces boulardii, widely used among probiotic supplements, seem to ameliorate Inflammatory Bowel Disease (IBD) progression and to promote mucosal healing. Intestinal Subepithelial Myofibroblasts (SEMFs) are key mediators in mucosal healing and fibrosis, mainly by migrating to the trauma region and secreting collagen. The aim of this study was to investigate the different effects of the aforementioned probiotic strains in the migration rate and the fibrotic responses of SEMFs.

Methods

L. plantarum and S. boulardii were reconstituted in SEMFs culture medium, identified by Gram staining and their viability was assessed by Trypan Blue staining. Primary SEMFs were isolated from colonic biopsies from healthy individuals and stimulated with 102 and 104 cfu/ml of each strain for: a) 6h, when mRNA expression of collagen type I, III, fibronectin, Tissue Factor and α-SMA was assessed by quantitative PCR, and b) 48h, when SEMFs’ migration rate was examined via Wound Healing Assay and protein collagen was measured via Sircol Assay.

Results

Trypan Blue staining confirmed the viability of the studied probiotics, and both the bacteria and the yeasts were stained Gram positive. Stimulation of SEMFs with L. plantarum resulted in upregulated mRNAs of Collagen type I (102cfu/ml: 1.6-fold, 104cfu/ml: 1.5-fold; p<0.001), type III (102cfu/ml: 1.7-fold, 104cfu/ml: 1.8-fold; p<0.0001), Fibronectin (102 cfu/ml, 1.5-fold, 104cfu/ml 1.5-fold; p<0.01), Tissue Factor (102cfu/ml: 1.4-fold, p<0.0001; 104cfu/ml: 1.3-fold, p<0.001) as well as SEMFs’ migration rate (102cfu/ml: 128.3%, 104cfu/ml: 124.1%; p<0.05). On the other hand, S. boulardii stimulation resulted in downregulated Collagen type I (102cfu/ml: 0.9-fold, p<0.01) and type III mRNAs (102cfu/ml: 0.8-fold, p<0.01), upregulated Tissue Factor mRNA (102cfu/ml: 1.2-fold, p<0.0001; 104cfu/ml: 1.1-fold, p<0.01), increased protein collagen production (104cfu/ml: by 211.6%, p<0.001) and increased SEMFs’ migration rate (104cfu/ml: 130.2%, p<0.05).

Conclusion

This study provides evidence that not only both probiotic strains remain viable in SEMFs’ culture medium but are also able to interact with SEMFs and alter their fibrotic behaviour. Moreover, it was shown that L. plantarum may promote mucosal healing, while S. boulardii could reduce profibrotic responses. Further preclinical research is needed to identify the optimal dosages and combinations of probiotic strains as potential auxiliary treatment of IBD.

The study was supported by «Strategic expansion of the Greek Biobanking Infrastructure» (BBMRI‐GR) in the framework of the Action "ENHANCING RESEARCH AND INNOVATION INFRASTRUCTURE - SECOND CYCLE" (NSRF 2014-2020) and “AMKE KLEON TSETIS” Foundation, Athens, Greece.