Evaluation of an O2-Substituted (1-3)-β-D-Glucan, Produced by Pediococcus parvulus 2.6, in ex vivo Models of Crohn's Disease.

Sara Notararigo,Alicia Prieto,Francisco Guarner,Iván Cristobo,María Antolín,Anna Otal,Paloma López,Encarnación Varela

doi:10.3389/fmicb.2021.621280

Abstract

1,3-β-glucans are extracellular polysaccharides synthesized by microorganisms and plants, with therapeutic potential. Among them, the O2-substituted-(1–3)-β-D-glucan, synthesized by some lactic acid bacteria (LAB), has a prebiotic effect on probiotic strains, an immunomodulatory effect on monocyte-derived macrophages, and potentiates the ability of the producer strain to adhere to Caco-2 cells differentiated to enterocytes. In this work, the O2-substituted-(1–3)-β-D-glucan polymers produced by GTF glycoyltransferase in the natural host Pediococcus parvulus 2.6 and in the recombinant strain Lactococcus lactis NZ9000[pNGTF] were tested. Their immunomodulatory activity was investigated in an ex vivo model using human biopsies from patients affected by Crohn’s disease (CD). Both polymers had an anti-inflammatory effect including, a reduction of Interleukine 8 both at the level of its gene expression and its secreted levels. The overall data indicate that the O2-substituted-(1–3)-β-D-glucan have a potential role in ameliorating inflammation via the gut immune system cell modulation.

Highlights

The exopolysaccharides (EPS) are large, lineal, or branched, extracellular carbohydrate polymers, produced by algae, plants, and bacteria
In the present pilot study, to evaluate EPS P and EPS L (Figure 1A), ex vivo tissue cultures have been used as a model of pathological intestinal inflammation (Figure 1B), in which the immune system plays an important role in the development, propagation, and maintenance of inflammation and disease
Laminarin was tested as a positive control due to its ability to activate the immune system through its interaction with the Dectin-1 receptor (Xie et al, 2010; Smith et al, 2018)

Summary

Introduction

The exopolysaccharides (EPS) are large, lineal, or branched, extracellular carbohydrate polymers, produced by algae, plants, and bacteria. They are commonly used as food additive due to their rheological properties (bio-thickener, gelling, or viscosifier agents) in the food industry. The EPS synthesized by LAB are divided into homopolysaccharides, if they contain only one monosaccharide type or heteropolysaccharides, if they contain various monosaccharides types (Werning et al, 2012). These EPS are known to support bacterial growth, as well as participate

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Conclusion