Food-Associated Lactobacillus plantarum and Yeasts Inhibit the Genotoxic Effect of 4-Nitroquinoline-1-Oxide.

Roberta Prete,Ermanno Federici,Aldo Corsetti,Giovanni Cenci,Aurora Ciarrocchi,Rosanna Tofalo

doi:10.3389/fmicb.2017.02349

Roberta Prete, Ermanno Federici + Show 4 more

Open Access

https://doi.org/10.3389/fmicb.2017.02349

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Abstract

Lactic acid bacteria and yeasts, representing the prevailing microbiota associated with different foods generally consumed without any cooking, were identified and characterized in vitro for some functional properties, such as acid-bile tolerance and antigenotoxic activity. In particular, 22 Lactobacillus plantarum strains and 14 yeasts were studied. The gastro-intestinal tract tolerance of all the strains was determined by exposing washed cell suspensions at 37°C to a simulated gastric juice (pH 2.0), containing pepsin (0.3% w/v) and to a simulated small intestinal juice (pH 8.0), containing pancreatin (1 mg mL-1) and bile extract (0.5%), thus monitoring changes in total viable count. In general, following a strain-dependent behavior, all the tested strains persisted alive after combined acid-bile challenge. Moreover, many strains showed high in vitro inhibitory activity against a model genotoxin, 4-nitroquinoline-1-oxide (4-NQO), as determined by the short-term method, SOS-Chromotest. Interestingly, the supernatants from bacteria- or yeasts-genotoxin co-incubations exhibited a suppression on SOS-induction produced by 4-NQO on the tester strain Escherichia coli PQ37 (sfiA::lacZ) exceeding, in general, the value of 75%. The results highlight that food associated microorganisms may reach the gut in viable form and prevent genotoxin DNA damage in situ. Our experiments can contribute to elucidate the functional role of food-associated microorganisms general recognized as safe ingested with foods as a part of the diet.

Highlights

Over the past decades, the food industry has been revolutionized toward the production of functional foods due to an increasing awareness of the consumers on the positive role of food in well-being and health
The antigenotoxic and antimutagenic activities are considered among the functional properties for characterizing probiotic microorganisms (Cenci et al, 2008; Trotta et al, 2012) and lactic acid bacteria (LAB) isolated from fermented foods have been found to decrease the genotoxicity of some chemical compounds (Burns and Rowland, 2000; Caldini et al, 2008; Novak et al, 2015)
L. plantarum WCSF1 and ATCC R 14917TM and two strains with documented probiotic activities, L. plantarum IMC 510 R and IMC 513 R (Synbiotec, Camerino, Italy), were used as reference strains for lactobacilli and a probiotic S. boulardii (Codex R, Zambon-Italia) as a reference strains for yeasts

Summary

Introduction

The food industry has been revolutionized toward the production of functional foods due to an increasing awareness of the consumers on the positive role of food in well-being and health. One way in which foods can be modified is by addition of probiotics, and fermented foods containing “live or active bacteria” or yeasts that provide benefits to gut health, might qualify as health-promoting foods (Shenderov, 2013; Hill et al, 2014). In this perspective, the ability of food-borne microbes to exert antigenotoxic properties and to make a protective role at gastro-intestinal level by inhibiting the biological activity. The most widely studied strains belong to the species Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Lactobacillus delbrueckii and other genera, such as Bifidobacterium and Bacillus (Caldini et al, 2002; Cenci et al, 2002; Raipulis et al, 2005), but the ability of Lactobacillus plantarum species to counteract genotoxic compounds in the gut is still not well-investigated (Corsetti et al, 2015)

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