Biomarkers and Utility of the Antioxidant Potential of Probiotic Lactobacilli and Bifidobacteria as Representatives of the Human Gut Microbiota

Abstract

Lactobacilli and bifidobacteria are an important part of human gut microbiota. Among numerous benefits, their antioxidant properties are attracting more and more attention. Multiple in vivo and in vitro studies have demonstrated that lactobacilli and bifidobacteria, along with their cellular components, possess excellent antioxidant capacity, which provides a certain degree of protection to the human body against diseases associated with oxidative stress. Recently, lactobacilli and bifidobacteria have begun to be considered as a new source of natural antioxidants. This review summarizes the current state of research on various antioxidant properties of lactobacilli and bifidobacteria. Special emphasis is given to the mechanisms of antioxidant activity of these bacteria in the human gut microbiota, which involve bacterial cell components and metabolites. This review is also dedicated to the genes involved in the antioxidant properties of lactobacilli and bifidobacteria strains as indicators of their antioxidant potential in human gut microbiota. Identification of the antioxidant biomarkers of the gut microbiota is of great importance both for creating diagnostic systems for assessing oxidative stress and for choosing strategies aimed at restoring the normal functioning of the microbiota and, through it, restoring human health. In this review, the practical application of probiotic strains with proven antioxidant properties to prevent oxidative stress is also considered.

Keywords: antioxidant; bifidobacteria; gut microbiota; lactobacilli; oxidative stress; probiotic.

Figure 1

Mechanisms of antioxidant action of lactobacilli and bifidobacteria inside the intestine of the host.AO: antioxidant; OS: oxidative stress; SCFAs: short-chain fatty acids; NF-κB: nuclear factor kappa B, eukaryotic transcription factor; SIRTs: a family of NAD-dependent protein deacetylases; PKC: protein kinase C; MAPKs: mitogen-activated protein kinases; SOD: superoxide dismutase; CAT: catalase; GSH: reduced glutathione; GSSH: oxidized glutathione; GSH-Px: glutathione peroxidase; GR: glutathione reductase; NRF2-Keap-ARE: a signaling system responsible for the expression of antioxidant-responsive elements (ARE-genes).

Figure 2

Effects of lactobacilli and bifidobacteria on cellular receptors and regulation of internal signal transduction systems of eukaryotic cells. ?: identified but undefined receptors and signaling molecules.