The aging of population has become an issue of great concern because of its rapid increase. Aging is an important risk factor of many chronic diseases. Resveratrol could be found in many foods, such as grapes, red wine, peanuts, and blueberries. Many studies reported that resveratrol possessed various bioactivities, such as antioxidant, anti-inflammatory, cardiovascular protection, anticancer, antidiabetes mellitus, antiobesity, neuroprotection, and antiaging effects. The antiaging mechanisms of resveratrol were mainly ameliorating oxidative stress, relieving inflammatory reaction, improving mitochondrial function, and regulating apoptosis. Resveratrol could be an effective and safe compound for the prevention and treatment of aging and age-related diseases. In this review, we summarize the effects of resveratrol on aging, life extension, and several age-related diseases, with special attention paid to the mechanisms of antiaging action.

The gut microbiota and their metabolites could play an important role in health and diseases of human beings. Short-chain fatty acids (SCFAs) are mainly produced by gut microbiome fermentation of dietary fiber and could also be produced by bacteria of the skin and vagina. Acetate, propionate, and butyrate are three major SCFAs, and their bioactivities have been widely studied. The SCFAs have many health benefits, such as anti-inflammatory, immunoregulatory, anti-obesity, anti-diabetes, anticancer, cardiovascular protective, hepatoprotective, and neuroprotective activities. This paper summarizes health benefits and side effects of SCFAs with a special attention paid to the mechanisms of action. This paper provides better support for people eating dietary fiber as well as ways for dietary fiber to be developed into functional food to prevent diseases.

Kombucha is a popular beverage with various bioactivities (such as antioxidant activity), which can be attributed to its abundant bioactive compounds, especially polyphenols. Kombucha is conventionally prepared by fermentation of a sugared black tea infusion without tea residue. In this study, the effects of black tea residue and green tea residue on kombucha were studied, and its antioxidant activities, total phenolic contents, as well as concentrations of polyphenols at different fermentation stages were evaluated using ferric-reducing antioxidant power, Trolox equivalent antioxidant capacity, Folin-Ciocalteu method and high-performance liquid chromatography with a photodiode array detector. The results showed that fermentation with tea residue could markedly increase antioxidant activities (maximum 3.25 times) as well as polyphenolic concentrations (5.68 times) of kombucha. In addition, green tea residue showed a stronger effect than black tea residue. Overall, it is interesting to find that fermentation with tea residues could be a better strategy to produce polyphenol-rich kombucha beverages.

Gut microbiota dysbiosis has been a crucial contributor to the pathogenesis of alcoholic fatty liver disease (AFLD). Tea is a popular beverage worldwide and exerts antioxidant and anti-inflammatory activities, as well as hepatoprotective effects. However, the potential role of gut microbiota regulated by tea in the prevention and management of AFLD remains unclear. Here, the protective effects of oolong tea, black tea, and dark tea on AFLD and its regulation of gut microbiota in chronic alcohol-exposed mice were explored and investigated. The results revealed that tea supplementation significantly prevented liver steatosis, decreased oxidative stress and inflammation, and modulated gut microbiota in chronic alcohol-exposed mice, especially oolong tea and dark tea. However, black tea showed less effectiveness against liver injury caused by alcohol. Moreover, the diversity, structure and composition of chronic alcohol-disrupted gut microbiota were restored by the supplementation of oolong tea and dark tea based on the analysis of gut microbiota. Furthermore, the relationship between liver injury biochemical indicators and gut microbiota indicated that some specific bacteria, such as Bacteroides, Alloprevotella, and Parabacteroides were closely associated with AFLD. In addition, the phytochemical components in tea extracts were measured by high-performance liquid chromatography, which could contribute to preventive effects on AFLD. In summary, oolong tea and dark tea could prevent chronic alcohol exposure-induced AFLD by modulating gut microbiota.

Kombucha beverage is commonly prepared by black tea infusion fermentation without tea residues, and possesses various health benefits. In this paper, kombucha beverages of two non-Camellia sinensis teas, including vine tea (Ampelopsisgrossedentata) and sweet tea (Rubus suavissimus), were studied for the first time. The antioxidant activities and polyphenol contents of kombucha beverages were evaluated by ferric-reducing antioxidant power assay, Trolox equivalent antioxidant capacity assay, and Folin-Ciocalteu method, respectively. In addition, effects of tea residues on antioxidant capacities of kombucha beverages were evaluated. The results showed that kombucha beverages from vine tea and sweet tea possessed strong antioxidant activities (especially vine tea kombucha), and fermentation with tea residues could significantly increase antioxidant capacities (maximum increase of 38%) and total phenolic content (maximum increase of 55%) of two kombucha beverages compared with those without tea residues. Moreover, the sensory evaluations showed that the sensory evaluation scores of kombucha with tea residues could be improved compared with those without tea residues. Furthermore, the concentrations of several bioactive components in the kombucha beverages were detected by high-performance liquid chromatography. These kombucha beverages could be used for prevention of several diseases with related of oxidative stress.