Isolation and characterization of five novel probiotic strains from Korean infant and children faeces.

Sun-Young Kook,Seokjin Kim,Dong Wan Lee,Yaelim Lee,Eui-Chun Chung,Sudarshan Kumar

doi:10.1371/journal.pone.0223913

Abstract

Probiotics are dietary supplements containing viable, non-pathogenic microorganisms that interact with the gastrointestinal microflora and directly with the immune system. The possible health effects of probiotics include modulating the immune system and exerting antibacterial, anticancer, and anti-mutagenic effects. The purpose of this study was to isolate, identify, and characterize novel strains of probiotics from the faeces of Korean infants. Various assays were conducted to determine the physiological features of candidate probiotic isolates, including Gram staining, 16S rRNA gene sequencing, tolerance assays to stimulated gastric juice and bile salts, adherence ability assays, antibiotic susceptibility testing, and assays of immunomodulatory effects. Based on these morphological and biochemical characteristics, five potential probiotic isolates (Enterococcus faecalis BioE EF71, Lactobacillus fermentum BioE LF11, Lactobacillus plantarum BioE LPL59, Lactobacillus paracasei BioE LP08, and Streptococcus thermophilus BioE ST107) were selected. E. faecalis BioE EF71 and L. plantarum BioE LPL59 showed high tolerance to stimulated gastric juice and bile salts, and S. thermophilus BioE ST107 as well as these two strains exhibited stronger adherence ability than reference strain Lactobacillus rhamnosus GG. All five strains inhibited secretion of lipopolysaccharide-induced pro-inflammatory cytokines IL-6 and TNF-α in RAW264.7 macrophages in vitro. L. fermentum BioE LF11, L. plantarum BioE LPL59, and S. thermophilus BioE ST107 enhanced the production of anti-inflammatory cytokine IL-10. Overall, our findings demonstrate that the five novel strains have potential as safe probiotics and encouraged varying degrees of immunomodulatory effects.

Highlights

Probiotics defined as “living micro-organisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition”, have become a major topic of lactic acid bacteria research over the past 20 years [1]
A phylogenetic tree was created to show the species relationships of the isolates (Fig 1). These five isolates were patent deposited in the Korean Collection for Type Cultures (KCTC) under the following strain names: E. faecalis BioE EF71 (KCTC 18627P), L. fermentum BioE LF11 (KCTC 18628P), L. paracasei BioE LP08 (KCTC 18629P), L. plantarum BioE LPL59 (KCTC 18630P), and S. thermophilus BioE ST107 (KCTC 18631P)
We identified five probiotics isolates (E. faecalis BioE EF71, L. fermentum BioE LF11, L. paracasei BioE LP08, L. plantarum BioE LPL59, and S. thermophilus BioE ST107) that showed improved tolerance to acid and bile and enhanced anti-inflammatory properties compared to other potential probiotics

Summary

Introduction

Probiotics defined as “living micro-organisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition”, have become a major topic of lactic acid bacteria research over the past 20 years [1]. Probiotics are usually considered dietary supplements and contain viable, non-pathogenic microorganisms that interact with the gastrointestinal microflora and directly with the immune system [2]. Immunomodulatory effects of five novel probiotic strains

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Conclusion