Revealing the Potential Impacts of Nutraceuticals Formulated with Freeze-Dried Jabuticaba Peel and Limosilactobacillus fermentum Strains Candidates for Probiotic Use on Human Intestinal Microbiota.

This study evaluated the impacts of novel nutraceuticals formulated with freeze-dried jabuticaba peel (FJP) and three potentially probiotic Limosilactobacillus fermentum strains on the abundance of bacterial groups forming the human intestinal microbiota, metabolite production, and antioxidant capacity during in vitro colonic fermentation. The nutraceuticals had high viable counts of L. fermentum after freeze-drying (≥ 9.57 ± 0.09 log CFU/g). The nutraceuticals increased the abundance of Lactobacillus ssp./Enterococcus spp. (2.46-3.94%), Bifidobacterium spp. (2.28-3.02%), and Ruminococcus albus/R. flavefaciens (0.63-4.03%), while decreasing the abundance of Bacteroides spp./Prevotella spp. (3.91-2.02%), Clostridium histolyticum (1.69-0.40%), and Eubacterium rectale/C. coccoides (3.32-1.08%), which were linked to positive prebiotic indices (> 1.75). The nutraceuticals reduced the pH and increased the sugar consumption, short-chain fatty acid production, phenolic acid content, and antioxidant capacity, besides altering the metabolic profile during colonic fermentation. The combination of FJP and probiotic L. fermentum is a promising strategy to produce nutraceuticals targeting intestinal microbiota.

Investigating the effects of conventional and unconventional edible parts of red beet (Beta vulgaris L.) on target bacterial groups and metabolic activity of human colonic microbiota to produce novel and sustainable prebiotic ingredients.

This study investigated the effects of freeze-dried red beet root (FDBR) and freeze-dried red beet stem and leaves (FDBSL) on target bacterial groups and metabolic activity of human colonic microbiota in vitro. The capability of FDBR and FDBSL to cause alterations in the relative abundance of different selected bacterial groups found as part of human intestinal microbiota, as well as in pH values, sugar, short-chain fatty acid, phenolic compounds, and antioxidant capacity were evaluated during 48 h of in vitro colonic fermentation. FDBR and FDBSL were submitted to simulated gastrointestinal digestion and freeze-dried prior to use in colonic fermentation. FDBR and FDBSL overall increased the relative abundance of Lactobacillus spp./Enterococcus spp. (3.64-7.60%) and Bifidobacterium spp. (2.76-5.78%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (9.56-4.18%), Clostridium histolyticum (1.62-1.15%), and Eubacterium rectale/Clostridium coccoides (2.33-1.49%) during 48 h of colonic fermentation. FDBR and FDBSL had high positive prebiotic indexes (>3.61) during colonic fermentation, indicating selective stimulatory effects on beneficial intestinal bacterial groups. FDBR and FDBSL increased the metabolic activity of human colonic microbiota, evidenced by decreased pH, sugar consumption, short-chain fatty acid production, alterations in phenolic compound contents, and maintenance of high antioxidant capacity during colonic fermentation. The results indicate that FDBR and FDBSL could induce beneficial alterations in the composition and metabolic activity of human intestinal microbiota, as well as that conventional and unconventional red beet edible parts are candidates to use as novel and sustainable prebiotic ingredients.

Chemical composition and prebiotic activity of baru (Dipteryx alata Vog.) pulp on probiotic strains and human colonic microbiota.

Little knowledge is available in literature regarding the chemical composition and health-promoting effects of baru (Dipteryx alata Vog.) pulp, a by-product usually discarded by the agro-industry during the processing of baru fruit. This study evaluated the chemical composition of baru pulp and investigated its prebiotic activity on distinct probiotic strains and human colonic microbiota with in vitro assays. Baru pulp had high contents of insoluble dietary fibers and phenolic compounds (mainly hesperidin). Baru pulp stimulated the growth and metabolism of the probiotics Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus acidophilus LA-05, and Lacticaseibacillus casei L-26. In addition, digested baru pulp induced significant benefits on the human colonic microbiota, increasing the relative abundance of Lactobacillus-Enterococcus, Bifidobacterium, and Bacteroides-Prevotella, as well as the production of lactate, acetate, propionate, and butyrate. The results show that baru pulp has potential prebiotic properties to be explored in the formulation of new health-promoting foods.

Nutraceutical formulations combining Limosilactobacillus fermentum, quercetin, and or resveratrol with beneficial impacts on the abundance of intestinal bacterial populations, metabolite production, and antioxidant capacity during colonic fermentation.

This study evaluated the impacts of different nutraceutical formulations combining Limosilactobacillus fermentum 296 (∼10 log CFU/mL), quercetin (QUE, 160 mg), and or resveratrol (RES, 150 mg) on the relative abundance of various intestinal bacterial populations, production of microbial metabolites, and antioxidant capacity during 48 h of in vitro colonic fermentation. The nutraceutical formulations increased the relative abundance of Lactobacillus spp./Enterococcus spp. and Bifidobacterium spp. and decreased the relative abundance of Bacteroides spp./Prevotella spp., Clostridium histolyticum, and E. rectale/C. coccoides during the colonic fermentation. Medium with the formulation containing L. fermentum, QUE, and RES had the highest prebiotic indexes, indicating synergistic or additive interaction between QUE and RES to modulate the intestinal microbiota. The nutraceutical formulations increased the production of bioactive metabolites and antioxidant capacity in the colonic fermentation media. The results indicate the capability of the tested nutraceutical formulations to beneficially modulate the composition and metabolite production of human intestinal microbiota and increase the antioxidant capacity in the intestinal environment.

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.

A fibre and phenolic-rich flour from Isabel grape by-products with stimulatory effects on distinct probiotics and beneficial impacts on human colonic microbiota in vitro.

This study evaluated the effects of a fibre and phenolic-rich flour (IGF) prepared from Isabel grape by-products on the growth and metabolism of different probiotics and distinct bacterial populations part of the human intestinal microbiota during an in vitro colonic fermentation. IGF was submitted to simulated gastrointestinal digestion before use in the experiments. IGF favoured the growth of the probiotics Lactobacillus acidophilus La-05, L. casei L-26 and Bifidobacterium lactis Bb-12, with viable counts of >7 log CFU per ml, as well as caused decreases in pH values and increases in organic acid production in the growth medium during 48 h of cultivation. IGF increased the population of beneficial micro-organisms forming the human intestinal microbiota, particularly Lactobacillus spp., decreased the pH values, and increased the lactic acid and short-chain fatty acid (acetic, butyric and propionic acids) production during 24 h of in vitro colonic fermentation. These results indicate the potential prebiotic effects of IGF, which should represent a novel sustainable added-value ingredient with functional properties and gut-health benefits.

Effects of digested flours from four different sweet potato (Ipomoea batatas L.) root varieties on the composition and metabolic activity of human colonic microbiota in vitro.

This study evaluated the effects of flours from four different sweet potato root (SPR) varieties, being two with white peel and two with purple peel, on the composition and metabolic activity of human colonic microbiota in vitro. The capability of these SPR flours (20 g/L) to cause alterations in relative abundance of different bacterial groups found as part of human colonic microbiota, as well as in lactic acid and short-chain fatty acid production was evaluated during 48 hr of an in vitro colonic fermentation. The SPR flours were submitted to a simulated gastrointestinal digestion prior to use in experiments. The four SPR flours increased the relative abundance of Lactobacillus/Enterococcus (range: 0.49-4.48%) and Bifidobacterium (range: 0.32-3.27%) and decreased the relative abundance of Bacteroides/Prevotella (range: 0.29-7.49%), Clostridium histolyticum (range: 0.15-2.08%), and Eubacterium rectale/Clostridium coccoides (range: 0.28-3.86%) during the 48 hr of colonic fermentation. The four SPRF flours had positive prebiotic indexes (> 0.38) after 24 and 48 hr of colonic fermentation, reinforcing the occurrence of selective stimulatory effects on colonic microbiota. An increased metabolic activity of human colonic microbiota was caused by tested SPR flours, which was evidenced by decreased pH (range: 3.20-3.83) and increased lactic acid and short chain fatty acid production during the 48 hr of colonic fermentation. The four examined SPR flours were capable of causing positive alterations in composition and driving the metabolic activity of human colonic microbiota during in vitro colonic fermentation, which should be linked to their prebiotic properties. PRACTICAL APPLICATION: The four examined sweet potato root flours (SPRF) caused beneficial alterations in composition besides of driving the metabolic activity of human colonic microbiota in vitro. These results characterize the examined SPRF as candidates for use as prebiotic ingredients by food industry for formulation of value-added functional foods or dietary supplements.

Effects of Quercetin and Resveratrol on in vitro Properties Related to the Functionality of Potentially Probiotic Lactobacillus Strains.

The ability of probiotics to exert benefits on host has been associated with different physiological functionalities in these microorganisms, namely cell surface hydrophobicity, autoaggregation, coaggregation with pathogens, antagonistic activity against pathogens and ability to survive the exposure to gastrointestinal conditions. This study assessed the effects of different concentrations of quercetin (QUE) and resveratrol (RES) on the ability of six potentially probiotic Lactobacillus strains to tolerate different pH values and bile salt concentrations, to autoaggregate, coaggregate with and antagonize pathogens and survive the exposure to simulated gastrointestinal conditions. QUE and RES presented low inhibitory effects on all tested Lactobacillus strains, with minimum inhibitory concentration (MIC) ranging from 512 to >1024 µg/mL. In most cases, QUE and RES at all tested concentrations (i.e., MIC, 1/2 MIC, and 1/4 MIC) did not affect the tolerance of the Lactobacillus strains to acidic pH and bile salts. QUE increased cell surface hydrophobicity of most of the tested Lactobacillus strains and increases or decreases in cell surface hydrophobicity varied in the presence of different RES concentrations among some strains. QUE and RES increased the ability of tested Lactobacillus strains to autoaggregate and coaggregate with pathogens. QUE and RES did not negatively affect the antagonistic activity of the tested Lactobacillus strains against pathogens and did not decrease their survival rates when exposed to in vitro gastrointestinal conditions. In a few cases, the ability of some tested Lactobacillus strains to antagonize pathogens, as well as to survive specific steps of the in vitro digestion was increased by QUE and RES. QUE exerted overall better protective effects on the measured in vitro properties of tested Lactobacillus strains than RES, and L. fermentum and L. plantarum strains presented better responses when treated with QUE or RES. These results showed that probiotic Lactobacillus strains could present low susceptibility to QUE and RES. Combined use of QUE and RES with probiotic Lactobacillus could improve their functionalities on the host; however, the concentration of these polyphenols should be carefully selected to achieve the desirable effects and vary according to the selected probiotic strain.