Ameliorative Effect of Ellagic Acid on Aging in Rats with the Potential Mechanism Relying on the Gut Microbiota and Urolithin A-Producing Ability.

Ellagic acid (EA) exhibits potential antiaging activity. Differences in individual ability to produce urolithins may result in large interindividual variability in the health effects of EA. Therefore, the effects and mechanism of EA on d-galactose-induced aging, considering urolithin A-producing ability, were investigated. Our results showed that EA improved cognitive impairment and hippocampal damage, increased the GABA (by 107.84-117.86%) and 5-HT (by 72.56-100.85%) levels, and suppressed the inflammatory and oxidative stress in aging rats. Thirteen plasma metabolites and 12 brain metabolites were improved by EA administration in aging rats. In particular, EA showed a better anti-aging effect in high-UroA-producing rats than in the low counterparts, while antibiotic intervention almost offset EA-alleviated aging induced by d-gal. Furthermore, the lower ratio of Firmicutes and Bacteroidota as well as the greater abundances of Akkermansia (by 139.21%), Bifidobacterium (by 88.04%), Clostridium_sensu_stricto_1 (by 183.47%), Lactobacillus (by 97.23%), and Turicibacter (by 83.06%) were observed in the high-UroA-producing group compared with the model group (p < 0.05). These findings provide novel insights into the anti-aging effects of EA and suggest that the ability of the gut microbiota responding to EA largely determines EA's anti-aging performance.

Potential of Establishing the Corresponding Human Microbial Community in Pseudo Germ-Free Mice through Fecal Microbe Transfer from Three Urolithin Metabotypes.

Three urolithin metabotypes (UMs) have been defined in the population according to final urolithins converted by gut microbiota. Currently, it is difficult to establish the cause-and-effect relationship between urolithins and microbiota in human studies. Studies on the health effects of ellagic acid (EA) in animal models rarely consider the differences in the urolithin production. Therefore, the objective of this study is to establish human microbiota-associated (HMA) mice, imitating the microbiota composition of the three UMs. Antibiotic-induced pseudo germ-free mice were gavaged with fecal bacteria of the three UM donors for four weeks. The results showed that the ability to produce corresponding urolithins was successfully transferred from the donor of the three UMs to HMA mice. The three UM HMA mice adopted a humanized microbiota profile similar to their corresponding donor. The family Eggerthellaceae and genera Eggerthella and Gordonibacter were successfully transferred and colonized from UM-A/B donors to HMA mice. Overall, the three UM HMA mouse models were successfully established, which provide a basis for exploring the health effects of EA.

Free and Bound Phenolic Profiles of Rosa roxburghii Tratt Leaves and Their Antioxidant and Inhibitory Effects on α-Glucosidase.

Rosa roxburghii Tratt (R. roxburghii) tea is a traditional Chinese beverage. This study aims to investigate and compare the phenolics in free and bound forms of two cultivars of R. roxburghii leaves, and their bioactivities. The total phenolic content of free and bound fractions was 72.71 and 17.75 mg GAE/g DW in Gui Nong No. 5 (GNN5) and 94.28 and 11.19 mg GAE/g DW in Seedless Cili (SC). A total of 37 phenolic compounds were characterized and quantified by UPLC-Q-Exactive Orbitrap/MS with ellagic acid, quercitrin, isoquercitrin, and quininic acid in free fraction, while gallic acid, ellagic acid, and hyperoside were main compounds in bound fraction. The free fraction with higher phenolic contents also showed excellent performances on antioxidant activities and α-glucosidase inhibitory potency than bound phenolics. Therefore, the results highlight that R. roxburghii leaves are a promising source enriched in phenolic constituents for functional beverages and nutritional foods.

Distribution of Urolithins Metabotypes in Healthy Chinese Youth: Difference in Gut Microbiota and Predicted Metabolic Pathways.

This is the first study to report the distribution of urolithin metabotypes (UMs) in Asian people, specifically in the Chinese. As was reported for Europeans and Latin Americans, three UMs were observed, UM-A (54.3%), UM-B (31.4%), and UM-0 (14.3%), in 35 healthy Chinese youth. The richness and diversity of gut microbiota were lower in UM-0 than in UM-A and UM-B at the genus level. Gordonibacter in UM-A and UM-B was significantly higher than that in UM-0. The Akkermansia was not found in UM-0. The correlation analysis between the type and content of urolithins and the gut microbiota at the genus level showed that 27 genera were significantly positively correlated with urolithin A and 20 genera were significantly positively associated with isourolithin A and urolithin B. In addition, different KEGG pathways such as TCA cycle, energy metabolism, and some disease were found between the gut microbiome of the three UMs. Further research is needed to explore the mechanisms of metabotypes and the differential health benefits or illness predisposition of the three UMs.

Phenolic profiles, bioaccessibility and antioxidant activity of plum (Prunus Salicina Lindl).

Plum (Prunus Salicina Lindl) is a rich source of phenolic compounds. However, the bound phenolics and its bioaccessibility and antioxidant activity remain unclear. Hence, the purpose of this study was to determine: 1) phenolic profiles of plum, including both free and bound phenolic fractions, 2) bioaccessibility of phenolic compounds in plum during simulated gastrointestinal digestions, 3) their antioxidant properties. A total of 17 phenolic compounds were identified by UPLC-Q-Exactive Orbitrap/MS with most epicatechin, neochlorogenic acid and procyanidin B2 in the free phenolics fraction, while catechin and epicatechin was the main compounds in the bound phenolics fraction. After the gastrointestinal digestion phase, the most bioaccessible phenolics were quercetin-pentoside (61.64%), cyanidin-3-O-glucoside (43.26%), and naringenin-7-O-ß-D-glucoside (42.04%). The antioxidant capacity of both undigested plum and its digested fractions showed a positive correlation with the total phenolics, and with specific individual phenolic compounds such as neochlorogenic acid, epicatechin and procyanidin B2 in undigested plum whereas catechin, neochlorogenic acid, and epicatechin in digested one. The results confirm that bound fraction of plum contribution to the total phenolic content must be taken into account in the assessment of the improving human health effects of plum.