In vitro colonic fermentation and potential prebiotic properties of pre-digested jabuticaba (Myrciaria jaboticaba (Vell.) Berg) by-products.

Jabuticaba (Myrciaria jaboticaba (Vell.) Berg) by-products (JB) are rich sources of dietary fiber and phenolic compounds, which can be fermented by intestinal microbiota to promote health benefits. This study evaluated the effects of a 48 h-in vitro colonic fermentation of pre-digested JB on the contents of phenolic compounds and sugars, production of organic acids, and abundance (%) of bacterial groups found as part of the human intestinal microbiota. JB reduced the pH (4.35) and promoted changes on phenolic compounds (profile and contents) and sugars, as well as production of short-chain fatty acids during the fermentation. JB increased the abundance of Lactobacillus spp./Enterococcus spp. (4.32-6.25%) and Bifidobacterium spp. (4.60-10.03%) during the fermentation, and decreased the abundance of Bacteroides spp./Prevotella spp. (7.50-10.71%), Eubacterium rectale/Clostridium coccoides (1.37-3.70%), and C. histolyticum (0.91-2.30%), resulting in positive prebiotic indexes (8.61-11.92). JB should contribute to beneficial changes in the human intestinal microbiota, with effects compatible with prebiotic ingredients.

Impact of Cashew (Anacardium occidentale L.) by-Product on Composition and Metabolic Activity of Human Colonic Microbiota In Vitro Indicates Prebiotic Properties.

Cashew apple by-product (CAB) is an important agro-industrial waste still underutilized, although it has been characterized as source of a variety of nutrients and bioactive compounds. This study evaluated the capability of freeze-dried CAB (FCAB) submitted to a simulated gastrointestinal digestion of inducing changes in relative abundance of distinct microbial groups found as part of human colonic microbiota, as well as in pH and short-chain fatty acid production during a 24-h in vitro fermentation using a pooled human fecal inocula. FCAB increased the relative abundance of Bifidobacterium and Lactobacillus/Enterococcus during colonic fermentation, besides to decrease the relative abundance of Bacteroides/Prevotella, Eubacterium rectale/Clostridium coccoides, and Clostridium histolyticum. FCAB increased the counts of lactic acid bacteria and decreased the counts of Enterobacteriaceae during colonic fermentation. Furthermore, FCAB decreased pH and increased the production of short-chain fatty acids in colonic fermentation media. These effects could be linked to contents of dietary fibers and the presence of fructans and different phenolic compounds found in FCAB. These results showed that FCAB induced positive alterations in composition and metabolic activity of human colonic microbiota in vitro, which indicate prebiotic properties.

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, 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.

Prebiotic activity of monofloral honeys produced by stingless bees in the semi-arid region of Brazilian Northeastern toward Lactobacillus acidophilus LA-05 and Bifidobacterium lactis BB-12.

This study assessed the in vitro prebiotic effects of honeys from Ziziphus joazeiro Mart. (juazeiro; J) and Mimosa arenosa Willd Poir (jurema branca; JB) produced by native stingless bees, namely Melipona subnitida Ducke (jandaíra; J) and M. scutellaris Latrelle (uruçu; U), in the Brazilian Northeastern semi-arid region toward the probiotics Lactobacillus acidophilus LA-05 and Bifidobacterium animalis subsp. lactis BB-12. Cells of the probiotic strains were enumerated over 48 h of cultivation in broths containing each honey (JJ, JU, JBJ or JBU) as a sole carbon source. The metabolic activities of probiotic strains in these media were assessed by measuring changes in pH values and sugars, organic acids and phenolics contents. All honeys (20 or 30 g/L) exerted growth promoting effects and displayed positive prebiotic activity scores (0.94-1.22) on tested probiotics. JJ showed the highest (p < 0.05) stimulatory effects on probiotics growth and prebiotic scores. At the end of the cultivation period, counts of L. acidophilus LA-05 and B. lactis BB-12 increased (p < 0.05) more than 2 log in broths regardless the monofloral honey added. The pH values and sugars contents decreased (p < 0.05), while the organic acids contents increased (p < 0.05) during cultivation of probiotics in broths containing JJ, JU, JBJ or JBU as carbon source. After 48 h of cultivation, contents of gallic, caftaric and caffeic acid, catechin and procyanidins (B1 and B2) decreased (p < 0.05) in media containing JJ, JU, JBJ or JBU despite of the inoculated probiotic. JJ honey presented overall the better stimulatory effects on the growth and metabolism of L. acidophilus LA-05 and B. lactis BB-12. These results showed for the first time the potential prebiotic properties of four monofloral honeys produced by stingless bees in the Brazilian Northeastern semi-arid region.

Protective Effects of Tropical Fruit Processing Coproducts on Probiotic Lactobacillus Strains during Freeze-Drying and Storage.

This study evaluated the protective effects of coproducts from agroindustrial processing of the tropical fruits acerola (Malpighia glabra L., ACE), cashew (Anacardium occidentale L., CAS), and guava (Psidium guayaba L., GUA) on the probiotics Lactobacillus paracasei L-10, Lactobacillus casei L-26, and Lactobacillus acidophilus LA-05 during freeze-drying and storage. The occurrence of damage to membrane integrity, membrane potential, and efflux activity of Lactobacillus cells after freeze-drying was evaluated by flow cytometry, and viable counts were measured immediately after freeze-drying and during 90 days of storage under refrigerated or room temperature conditions. Probiotic strains freeze-dried without substrate had the overall highest count reductions (0.5 ± 0.1 to 2.9 ± 0.3 log cycles) after freeze-drying. Probiotics freeze-dried with fruit processing coproducts had small cell subpopulations with damaged efflux activity and membrane potential. Average counts of probiotics freeze-dried with ACE, CAS, or GUA after 90 days of storage under refrigerated or room temperature were in the range of 4.2 ± 0.1 to 5.3 ± 0.2 and 2.6 ± 0.3 to 4.9 ± 0.2 log CFU/g, respectively, which were higher than those observed for strains freeze-dried without substrate. The greatest protective effects on freeze-dried probiotics were overall presented by ACE. These results revealed that ACE, CAS, and GUA can exert protective effects and increase the stability of probiotic lactobacilli during freeze-drying and storage, in addition to supporting a possible added-value destination for these agroindustrial coproducts as vehicles for probiotics and for the development of novel functional foods.