Abstract
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, 20 g/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 48 h of cultivation in media with XCJ (20 g/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 48 h-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 48 h-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 (20 g/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.