Polyphenols (PPs) are the naturally occurring bioactive components in fruits and vegetables, and they are the most abundant antioxidant in the human diet. Studies are suggesting that ingestion of PPs might be helpful to ameliorate metabolic syndromes that may contribute in the prevention of several chronic disorders like diabetes, obesity, hypertension, and colon cancer. PPs have structural diversity which impacts their bioavailability as they accumulate in the large intestine and are extensively metabolized through gut microbiota (GM). Intestinal microbiota transforms PPs into their metabolites to make them bioactive. Interestingly, not only GM act on PPs to metabolize them but PPs also modulate the composition of GM. Thus, change in GM from pathogenic to beneficial ones may be helpful to ameliorate gut health and associated diseases. However, to overcome the low bioavailability of PPs, various approaches have been developed to improve their solubility and transportation through the gut. In this review, we present evidence supporting the structural changes that occur after metabolic reactions in PPs (curcumin, quercetin, and catechins) and their effect on GM composition that leads to improving overall gut health and helping to ameliorate metabolic disorders.

The gut microbiota (GM) represents a diverse and dynamic population of microorganisms and about 100 trillion symbiotic microbial cells that dwell in the gastrointestinal tract. Studies suggest that the GM can influence the health of the host, and several factors can modify the GM composition, such as diet, drug intake, lifestyle, and geographical locations. Gut dysbiosis can affect brain immune homeostasis through the microbiota–gut–brain axis and can play a key role in the pathogenesis of neurodegenerative diseases, including dementia and Alzheimer’s disease (AD). The relationship between gut dysbiosis and AD is still elusive, but emerging evidence suggests that it can enhance the secretion of lipopolysaccharides and amyloids that may disturb intestinal permeability and the blood–brain barrier. In addition, it can promote the hallmarks of AD, such as oxidative stress, neuroinflammation, amyloid-beta formation, insulin resistance, and ultimately the causation of neural death. Poor dietary habits and aging, along with inflammatory responses due to dysbiosis, may contribute to the pathogenesis of AD. Thus, GM modulation through diet, probiotics, or fecal microbiota transplantation could represent potential therapeutics in AD. In this review, we discuss the role of GM dysbiosis in AD and potential therapeutic strategies to modulate GM in AD.

Curcumin is a polyphenolic natural compound with diverse and attractive biological properties, which may prevent or ameliorate pathological processes underlying age-related cognitive decline, Alzheimer’s disease (AD), dementia, or mode disorders. AD is a chronic neurodegenerative disorder that is known as one of the rapidly growing diseases, especially in the elderly population. Moreover, being the eminent cause of dementia, posing problems for families, societies as well a severe burden on the economy. There are no effective drugs to cure AD. Although curcumin and its derivatives have shown properties that can be considered useful in inhibiting the hallmarks of AD, however, they have low bioavailability. Furthermore, to combat diagnostic and therapeutic limitations, various nanoformulations have also been recognized as theranostic agents that can also enhance the pharmacokinetic properties of curcumin and other bioactive compounds. Nanocarriers have shown beneficial properties to deliver curcumin and other nutritional compounds against the blood-brain barrier to efficiently distribute them in the brain. This review spotlights the role and effectiveness of curcumin and its derivatives in AD. Besides, the gut metabolism of curcumin and the effects of nanoparticles and their possible activity as diagnostic and therapeutic agents in AD also discussed.

The consumption of plant sprouts as part of human day-to-day diets is gradually increasing, and their health benefit is attracting interest across multiple disciplines. The purpose of this review was to (a) critically evaluate the phytochemicals in selected sprouts (alfalfa, buckwheat, broccoli, and red cabbage), (b) describe the health benefits of sprouts, (c) assess the recent advances in sprout production, (d) rigorously evaluate their safety, and (e) suggest directions that merit special consideration for further novel research on sprouts. Young shoots are characterized by high levels of health-benefitting phytochemicals. Their utility as functional ingredients have been extensively described. Tremendous advances in the production and safety of sprouts have been made over the recent past and numerous reports have appeared in mainstream scientific journals describing their nutritional and medicinal properties. However, subjects such as application of sprouted seed flours in processed products, utilizing sprouts as leads in the synthesis of nanoparticles, and assessing the dynamics of a relationship between sprouts and gut health require special attention for future clinical exploration. Sprouting is an effective strategy allowing manipulation of phytochemicals in seeds to improve their health benefits.

With ever increased food processing in the new millennia, production of agro-industrial waste has been increased tremendously. Although, these waste are rich sources of essential bioactive compounds. In developing countries, the waste materials from agro-industries can help to obtain valuable components. The objective of this manuscript is to manage industrial potato peel waste and to highlight its nutritional and industrial uses. Potato peel waste, by various procedures such as fermentation, extraction and other treatments, can ensue into the products such as bio-fuels, dietary fibre, biofertilizer, biogas, biosorbent, antioxidants and food additives. This paper enlightens the application of potato peel utilization in food and nonfood purposes for example extraction, utilization of bioactive components, biotechnological usage, livestock feed and miscellaneous use. The present article summarized the literature pertaining to the studies of the last twenty years.

Gut microbiota (GM) play a role in the metabolic health, gut eubiosis, nutrition, and physiology of humans. They are also involved in the regulation of inflammation, oxidative stress, immune responses, central and peripheral neurotransmission. Aging and unhealthy dietary patterns, along with oxidative and inflammatory responses due to gut dysbiosis, can lead to the pathogenesis of neurodegenerative diseases, especially Alzheimer’s disease (AD). Although the exact mechanism between AD and GM dysbiosis is still unknown, recent studies claim that secretions from the gut can enhance hallmarks of AD by disturbing the intestinal permeability and blood–brain barrier via the microbiota–gut–brain axis. Dietary polyphenols are the secondary metabolites of plants that possess anti-oxidative and anti-inflammatory properties and can ameliorate gut dysbiosis by enhancing the abundance of beneficial bacteria. Thus, modulation of gut by polyphenols can prevent and treat AD and other neurodegenerative diseases. This review summarizes the role of oxidative stress, inflammation, and GM in AD. Further, it provides an overview on the ability of polyphenols to modulate gut dysbiosis, oxidative stress, and inflammation against AD.