Part Of Human Gut Microbiota Research Articles

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

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.

In vitro evaluation of potential prebiotic effects of a freeze-dried juice from Pilosocereus gounellei (A. Weber ex K. Schum. Bly. Ex Rowl) cladodes, an unconventional edible plant from Caatinga biome.

This study evaluated in vitro the potential prebiotic effects of a freeze-dried juice extracted from cladodes of Pilosocereus gounellei (A. Weber ex K. Schum.) Bly. Ex Rowl, an unconventional edible plant from Brazilian Caatinga biome and popularly known as xique-xique. Prebiotic effects of freeze-dried xique-xique cladode juice (XCJ, 20g/L) were evaluated by measurements of prebiotic activity scores and stimulatory effects on growth and metabolic activities of probiotic Lactobacillus acidophilus LA-05, L. casei L-26 and L. paracasei L-10, which are beneficial species found as part of human gut microbiota. XCJ showed positive prebiotic activity scores on all examined probiotics, indicating a selective stimulatory effect on these microorganisms in detriment to enteric pathogens. Examined probiotics had high viable counts (> 8 log CFU/mL) after 48h of cultivation in media with XCJ (20g/L), representing an increase of > 2 log CFU/mL when compared to viable counts found on time zero. Cultivation of probiotics in media with XCJ resulted in decreased pH during the 48h-incubation. Contents of fructose and glucose decreased in media with XCJ inoculated with L. acidophilus LA-05, L. casei L-26 or L. paracasei L-10 during the 48h-cultivation, in parallel with an increase in contents of acetic and lactic acids. Measured effects of XCJ on probiotics were overall similar to those exerted by fructoligosaccharides (20g/L), a proven prebiotic ingredient. These results showed that XCJ could exert selective stimulatory effects on different Lactobacillus species, which are indicative of potential prebiotic properties.