Preliminary probiotic and technological characterization of Pediococcus pentosaceus strain KID7 and in vivo assessment of its cholesterol-lowering activity.

Karthiyaini Damodharan,Seung Hwan Yang,Joo-Won Suh,Sasikumar A Palaniyandi,Young Sil Lee

doi:10.3389/fmicb.2015.00768

Abstract

The study was aimed to characterize the probiotic properties of a Pediococcus pentosaceus strain, KID7, by in vitro and in vivo studies. The strain possessed tolerance to oro-gastrointestinal transit, adherence to the Caco-2 cell line, and antimicrobial activity. KID7 exhibited bile salt hydrolase activity and cholesterol-lowering activity, in vitro. In vivo cholesterol-lowering activity of KID7 was studied using atherogenic diet-fed hypercholesterolemic mice. The experimental animals (C57BL/6J mice) were divided into 4 groups viz., normal diet-fed group (NCD), atherogenic diet-fed group (HCD), atherogenic diet- and KID7-fed group (HCD-KID7), and atherogenic diet- and Lactobacillus acidophilus ATCC 43121-fed group (HCD-L.ac) as positive control. Serum total cholesterol (T-CHO) level was significantly decreased by 19.8% in the HCD-KID7 group (P < 0.05), but not in the HCD-L.ac group compared with the HCD group. LDL cholesterol levels in both HCD-KID7 and HCD-L.ac groups were decreased by 35.5 and 38.7%, respectively, compared with HCD group (both, P < 0.05). Glutamyl pyruvic transaminase (GPT) level was significantly lower in the HCD-KID7 and HCD-L.ac groups compared to HCD group and was equivalent to that of the NCD group. Liver T-CHO levels in the HCD-KID7 group were reduced significantly compared with the HCD group (P < 0.05) but not in the HCD-L.ac group. Analysis of expression of genes associated with lipid metabolism in liver showed that low-density lipoprotein receptor (LDLR), cholesterol-7α-hydroxylase (CYP7A1) and apolipoprotein E (APOE) mRNA expression was significantly increase in the HCD-KID7 group compared to the HCD group. Furthermore, KID7 exhibited desired viability under freeze-drying and subsequent storage conditions with a combination of skim milk and galactomannan. P. pentosaceus KID7 could be a potential probiotic strain, which can be used to develop cholesterol-lowering functional food after appropriate human clinical trials.

Highlights

High blood cholesterol is a risk factor for cardiovascular diseases, which remains one of the largest causes of death worldwide (Ishimwe et al, 2015)
The probiotic strains Lactobacillus rhamnosus GG andLactobacillus acidophilus ATCC 43121 were obtained from American Type Culture Collection (ATCC, Manassas, VA, USA) and the type strain Pediococcus pentosaceus KACC 12311 was obtained from the Korean Agricultural Culture Collection (KACC), Republic of Korea
Identification of Strain KID7 Based on 16S rDNA Sequence and Biochemical Test BLAST search of the EzTaxon database showed that the 16S rDNA sequence of KID7 (Genbank accession number KJ810576) (1508 bp) showed 99.3% similarity with P. pentosaceus type strain DSM 20336

Summary

Introduction

High blood cholesterol (hypercholesterolemia) is a risk factor for cardiovascular diseases, which remains one of the largest causes of death worldwide (Ishimwe et al, 2015). Available literature suggests that probiotics with bile salt hydrolase (BSH) activity show cholesterol-lowering activity in vivo (Kumar et al, 2011; Jones et al, 2012, 2014; Pavlovic et al, 2012; Degirolamo et al, 2014). Other mechanisms such as cholesterol adsorption to cell surface, cholesterol assimilation into bacterial cell membrane (Liong and Shah, 2005a) and co-precipitation with deconjugated bile acids (Liong and Shah, 2005b) are proposed/demonstrated in vitro without evidence of their occurrence in vivo

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