Extra-virgin olive oil and the gut-brain axis: influence on gut microbiota, mucosal immunity, and cardiometabolic and cognitive health

In situ interaction of pea peptides and bile salts under in vitro digestion: Potential impact on lipolysis

The present work evaluated how a native pea protein isolate (PPI) affects the key roles carried out by bile salts (BS) in lipid digestion by means of the in vitro static INFOGEST protocol. Two gastric residence times were evaluated (10 and 60 min), and then the peptides obtained (GPPP) were mixed with BS at physiological concentration in simulated intestinal fluid to understand how they interact with BS both at the bulk and at the interface. Both GPPP give rise to a film with a predominant viscous character that does not constitute a barrier to the penetration of BS, but interact with BS in the bulk duodenal fluid. When the peptides flushing from the stomach after the different gastric residence times undergo duodenal digestion, it was found that for the longer gastric residence time the percentage of soluble fraction in the duodenal phase, that perform synergistically with BS micelles, was twice that of the lower residence time, leading to an increase in the solubilization of oleic acid. These results finally lead to a greater extent of lipolysis of olive oil emulsions. This work demonstrates the usefulness of in vitro models as a starting point to study the influence of gastric residence time of pea protein on its interaction with BS, affecting lipolysis. Pea proteins were shown to be effective emulsifiers that synergistically perform with BS improving the release and bioaccessibility of bioactive lipids as olive oil.

Effects of Tea Seed Oil Extracted by Different Refining Temperatures on the Intestinal Microbiota of High-Fat-Diet-Induced Obese Mice

Obesity has become one of the most serious chronic diseases threatening human health. Its onset and progression are closely related to the intestinal microbiota, as disruption of the intestinal flora promotes the production of endotoxins and induces an inflammatory response. This study aimed to investigate the variations in the physicochemical properties of various refined tea seed oils and their impact on intestinal microbiota disorders induced by a high-fat diet (HFD) through dietary intervention. In the present study, C57BL/6J mice on a HFD were randomly divided into three groups: HFD, T-TSO, and N-TSO. T-TSO and N-TSO mice were given traditionally refined and optimized tea seed oil for 12 weeks. The data revealed that tea seed oil obtained through degumming at 70 °C, deacidification at 50 °C, decolorization at 90 °C, and deodorization at 180 °C (at 0.06 MPa for 1 h) effectively removed impurities while minimizing the loss of active ingredients. Additionally, the optimized tea seed oil mitigated fat accumulation and inflammatory responses resulting from HFD, and reduced liver tissue damage in comparison to traditional refining methods. More importantly, N-TSO can serve as a dietary supplement to enhance the diversity and abundance of intestinal microbiota, increasing the presence of beneficial bacteria (norank_f__Muribaculaceae, Lactobacillus, and Bacteroides) while reducing pathogenic bacteria (Alistipes and Mucispirillum). Therefore, in HFD-induced obese C57BL/6J mice, N-TSO can better ameliorate obesity compared with a T-TSO diet, which is promising in alleviating HFD-induced intestinal microbiota disorders.

Comparative Analysis of Grape Seed Oil, Linseed Oil, and a Blend: In Vivo Effects of Supplementation

Grape seeds are rich in bioactive substances, including polyphenols, terpenoids, and phytosterols. Linseed (Linum usitatissimum L.) boasts a high concentration of polyunsaturated fatty acids (PUFAs), lignans, phytoestrogens, and soluble fibers, all contributing to its therapeutic potential. In this study, we pioneered the formulation of an oil blend (GL) combining grape seed oil (G) and golden linseed oil (GL) in equal volumes (1:1 (v/v)) and we evaluated in terms of the nutritional, physical, and chemical properties and their influence in an in vivo experimental model. We analyzed the oils by performing physical-chemical analyses, examining the oxidative stability using Rancimat; conducting thermal analyses via thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC), performing optical UV-vis absorption analyses; examining the fluorescence emission-excitation matrix, total carotenoids, and color, and conducting metabolic assessments in an in vivo experimental trial. The fatty acid profile presented a higher fraction of linoleic acid (C18:2) in G and GL and alpha-linolenic acid (C18:3) in L. The acidity and peroxide indices were within the recommended ranges. The TG/DTG, DSC, and Rancimat analyses revealed similar behaviors, and the optical analyses revealed color variations caused by carotenoid contents in L and GL. In the in vivo trial, G (G2: 2000 mg/kg/day) promoted lower total consumption, and the blend (GL: 2000 mg/kg/day) group exhibited less weight gain per gram of consumed food. The group with G supplementation (G2: 2000 mg/kg/day) and GL had the highest levels of HDL-c. The group with L supplementation (L2: 2000 mg/kg/day) had the lowest total cholesterol level. The L2, G1 (1000 mg/kg/day), and G2 groups exhibited the lowest MCP-1 and TNF-α values. Additionally, the lowest adipocyte areas occurred in G and GL. Our results suggest that this combination is of high quality for consumption and can influence lipid profiles, markers of inflammation, and antioxidant status.

Treating chronic stress and chronic pain by manipulating gut microbiota with diet: can we kill two birds with one stone?

Background: Chronic stress and chronic pain are closely linked by the capacity to exacerbate each other, sharing common roots in the brain and in the gut. The strict intersection between these two neurological diseases makes important to have a therapeutic strategy aimed at preventing both to maintain mental health in patients. Diet is an modifiable lifestyle factor associated with gut-brain axis diseases and there is growing interest in its use as adjuvant to main therapies. Several evidence attest the impact of specific diets or nutrients on chronic stress-related disorders and pain with a good degree of certainty. A daily adequate intake of foods containing micronutrients such as amino acids, minerals and vitamins, as well as the reduction in the consumption of processed food products can have a positive impact on microbiota and gut health. Many nutrients are endowed of prebiotic, anti-inflammatory, immunomodulatory and neuroprotective potential which make them useful tools helping the management of chronic stress and pain in patients. Dietary regimes, as intermittent fasting or caloric restriction, are promising, although further studies are needed to optimize protocols according to patient's medical history, age and sex. Moreover, by supporting gut microbiota health with diet is possible to attenuate comorbidities such as obesity, gastrointestinal dysfunction and mood disorders, thus reducing healthcare costs related to chronic stress or pain.Objective: This review summarize the most recent evidence on the microbiota-mediated beneficial effects of macro- and micronutrients, dietary-related factors, specific nutritional regimens and dietary intervention on these pathological conditions.

Oxidative Stress as a Target for Non-Pharmacological Intervention in MAFLD: Could There Be a Role for EVOO?

Oxidative stress plays a central role in most chronic liver diseases and, in particular, in metabolic dysfunction-associated fatty liver disease (MAFLD), the new definition of an old condition known as non-alcoholic fatty liver disease (NAFLD). The mechanisms leading to hepatocellular fat accumulation in genetically predisposed individuals who adopt a sedentary lifestyle and consume an obesogenic diet progress through mitochondrial and endoplasmic reticulum dysfunction, which amplifies reactive oxygen species (ROS) production, lipid peroxidation, malondialdehyde (MDA) formation, and influence the release of chronic inflammation and liver damage biomarkers, such as pro-inflammatory cytokines. This close pathogenetic link has been a key stimulus in the search for therapeutic approaches targeting oxidative stress to treat steatosis, and a number of clinical trials have been conducted to date on subjects with NAFLD using drugs as well as supplements or nutraceutical products. Vitamin E, Vitamin D, and Silybin are the most studied substances, but several non-pharmacological approaches have also been explored, especially lifestyle and diet modifications. Among the dietary approaches, the Mediterranean Diet (MD) seems to be the most reliable for affecting liver steatosis, probably with the added value of the presence of extra virgin olive oil (EVOO), a healthy food with a high content of monounsaturated fatty acids, especially oleic acid, and variable concentrations of phenols (oleocanthal) and phenolic alcohols, such as hydroxytyrosol (HT) and tyrosol (Tyr). In this review, we focus on non-pharmacological interventions in MAFLD treatment that target oxidative stress and, in particular, on the role of EVOO as one of the main antioxidant components of the MD.

Exploring the Impact of Extra Virgin Olive Oil on Maternal Immune System and Breast Milk Composition in Rats

Maternal breast milk plays a key role in providing newborns with passive immunity and stimulating the maturation of an infant's immune system, protecting them from many diseases. It is known that diet can influence the immune system of lactating mothers and the composition of their breast milk. The aim of this study was to establish if a supplementation during the gestation and lactation of Lewis rats with extra virgin olive oil (EVOO), due to the high proportion of antioxidant components in its composition, has an impact on the mother's immune system and on the breast milk's immune composition. For this, 10 mL/kg of either EVOO, refined oil (control oil) or water (REF group) were orally administered once a day to rats during gestation and lactation periods. Immunoglobulin (Ig) concentrations and gene expressions of immune molecules were quantified in several compartments of the mothers. The EVOO group showed higher IgA levels in both the breast milk and the mammary glands than the REF group. In addition, the gene expression of IgA in mammary glands was also boosted by EVOO consumption. Overall, EVOO supplementation during gestation and lactation is safe and does not negatively affect the mother's immune system while improving breast milk immune composition by increasing the presence of IgA, which could be critical for an offspring's immune health.

The Composition of Volatiles and the Role of Non-Traditional LOX on Target Metabolites in Virgin Olive Oil from Autochthonous Dalmatian Cultivars

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.

Association between Life's Essential 8 and cognitive function: insights from NHANES 2011-2014

Introduction

Life's Essential 8 (LE8) is prompted by the American Heart Association (AHA) to assess cardiovascular health. The association between LE8 and cognitive function in America is unknown. Our study was to investigate the association of LE8 with cognitive function in general adults.

Materials and methods

A total of 2,301 participants were enrolled in the National Health and Nutrition Examination Surveys (NHANES). LE8 scores (range 0-100) were obtained from measurements based on American Heart Association definitions, divided into health behavior and health factor scores. Cognitive function was assessed by three tests including the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal fluency test (AFT), and Digit Symbol Substitution test (DSST). The multivariable linear regression analysis explored the associations between LE8 and cognitive function. Smooth curve fitting was explored using restricted cubic splines. The inflection point was determined by the two-piecewise linear regression.

Results

In the multivariable linear regression model with full adjustment for confounding variables, AFT scores were 1.2 points higher in participants with LE8 scores >80 than in those with LE8 scores <50 (high LE8 score group: β = 1.20, 95% CI 0.37, 2.03), and 3.32 points higher in DSST (high LE8 score group: β = 3.32, 95% CI 1.24, 5.39). Although high LE8 scores show a Negative association with high CERAD, we found a significant association between higher LE8 scores and higher CERAD when LE8 scores were higher than 82.5 (β = 0.21 95%CI 0.04, 0.39, p-value = 0.0179).

Conclusion

Our study highlighted a positive association between Life's Essential 8 and cognitive function in older adults.

Evaluation of the protective and therapeutic effects of extra virgin olive oil rich in phenol in experimental model of neonatal necrotizing enterocolitis by clinical disease score, ınflammation, apoptosis, and oxidative stress markers

BACKGROUND AND AIM

Necrotizing Enterocolitis (NEC) is an inflammation-associated ischemic necrosis of the intestine. To investigate the effects of extra virgin olive oil (EVOO) on inflammation, oxidative stress, apoptosis, and histological changes in NEC-induced newborn rats.

MATERIALS AND METHODS

24 rats were randomly divided into three groups: control, NEC and NEC + EVOO. NEC induction was performed using hypoxia-hyperoxia, formula feeding, and cold stress. The NEC + EVOO group received 2 ml/kg EVOO with high phenolic content by gavage twice a day for 3 days. 3 cm of bowel including terminal ileum, cecum, and proximal colon was excised.

RESULTS

Weight gain and clinical disease scores were significantly higher in the NEC + EVOO group than in the NEC group (p < 0.001). EVOO treatment caused significant decreases in IL1β, IL6 levels (p = 0.016, p = 0.029 respectively) and EGF, MDA levels (p = 0.032, p = 0.013 respectively) compared to NEC group. Significant decreases were observed in IL6 gene expression in the NEC + EVOO group compared to the NEC group (p = 0.002). In the group NEC + EVOO, the number of Caspase-3 positive cells was found to be significantly reduced (p < 0.001) and histopathological examination revealed minimal changes and significantly lower histopathological scores (p < 0.001).

CONCLUSION

Phenol-rich EVOO prevents intestinal damage caused by NEC by inhibiting inflammation, oxidative stress, apoptosis.

Fermented foods: Harnessing their potential to modulate the microbiota-gut-brain axis for mental health

Over the past two decades, whole food supplementation strategies have been leveraged to target mental health. In addition, there has been increasing attention on the ability of gut microbes, so called psychobiotics, to positively impact behaviour though the microbiota-gut-brain axis. Fermented foods offer themselves as a combined whole food microbiota modulating intervention. Indeed, they contain potentially beneficial microbes, microbial metabolites and other bioactives, which are being harnessed to target the microbiota-gut-brain axis for positive benefits. This review highlights the diverse nature of fermented foods in terms of the raw materials used and type of fermentation employed, and summarises their potential to shape composition of the gut microbiota, the gut to brain communication pathways including the immune system and, ultimately, modulate the microbiota-gut-brain axis. Throughout, we identify knowledge gaps and challenges faced in designing human studies for investigating the mental health-promoting potential of individual fermented foods or components thereof. Importantly, we also suggest solutions that can advance understanding of the therapeutic merit of fermented foods to modulate the microbiota-gut-brain axis.

Torreya grandis oil attenuates cognitive impairment in scopolamine-induced mice

The oil of Torreya grandis (TGO), a common nut in China, is considered to be a bioactive edible oil and has a great value in functional food development. In this study, the neuroprotective effects of TGO were investigated on a scopolamine (SCOP)-induced C57BL/6J mouse model. The mice were pretreated with TGO for 30 days (1000 mg per kg per day and 3000 mg per kg per day, i.g.). Behavioral tests showed that the supplementation of TGO could prevent the cognitive deficits induced by SCOP. TGO rebalanced the disorder of the cholinergic system by upgrading the level of acetylcholine. TGO also alleviated the over-activation of microglia and inhibited neuroinflammation and oxidative stress. Additionally, TGO could regulate the composition of gut microbiota, increase the production of short-chain fatty acids, and decrease the content of lipopolysaccharides in the serum. In conclusion, TGO has the potential to prevent loss of memory and impairment of cognition, which may be related to its regulation of the gut microbiota-metabolite-brain axis.

Lipids, Gut Microbiota, and the Complex Relationship with Alzheimer's Disease: A Narrative Review

Alzheimer's Disease (AD) is a multifactorial, progressive, and chronic neurodegenerative disorder associated with the aging process. Memory deficits, cognitive impairment, and motor dysfunction are characteristics of AD. It is estimated that, by 2050, 131.5 million people will have AD. There is evidence that the gastrointestinal microbiome and diet may contribute to the development of AD or act preventively. Communication between the brain and the intestine occurs through immune cells in the mucosa and endocrine cells, or via the vagus nerve. Aging promotes intestinal dysbiosis, characterized by an increase in pro-inflammatory pathogenic bacteria and a reduction in anti-inflammatory response-mediating bacteria, thus contributing to neuroinflammation and neuronal damage, ultimately leading to cognitive decline. Therefore, the microbiota-gut-brain axis has a significant impact on neurodegenerative disorders. Lipids may play a preventive or contributory role in the development of AD. High consumption of saturated and trans fats can increase cortisol release and lead to other chronic diseases associated with AD. Conversely, low levels of omega-3 polyunsaturated fatty acids may be linked to neurodegenerative diseases. Unlike other studies, this review aims to describe, in an integrative way, the interaction between the gastrointestinal microbiome, lipids, and AD, providing valuable insights into how the relationship between these factors affects disease progression, contributing to prevention and treatment strategies.

Effects of Functional and Nutraceutical Foods in the Context of the Mediterranean Diet in Patients Diagnosed with Breast Cancer

Several studies report that breast cancer survivors (BCS) tend to have a poor diet, as fruit, vegetable, and legume consumption is often reduced, resulting in a decreased intake of nutraceuticals. Moreover, weight gain has been commonly described among BCS during treatment, increasing recurrence rate and mortality. Improving lifestyle and nutrition after the diagnosis of BC may have important benefits on patients' general health and on specific clinical outcomes. The Mediterranean diet (MD), known for its multiple beneficial effects on health, can be considered a nutritional pool comprising several nutraceuticals: bioactive compounds and foods with anti-inflammatory and antioxidant effects. Recent scientific advances have led to the identification of nutraceuticals that could amplify the benefits of the MD and favorably influence gene expression in these patients. Nutraceuticals could have beneficial effects in the postdiagnostic phase of BC, including helping to mitigate the adverse effects of chemotherapy and radiotherapy. Moreover, the MD could be a valid and easy-to-follow option for managing excess weight. The aim of this narrative review is to evaluate the recent scientific literature on the possible beneficial effects of consuming functional and nutraceutical foods in the framework of MD in BCS.

Evaluation of the Bioaccessible Fraction of T-2 Toxin from Cereals and Its Effect on the Viability of Caco-2 Cells Exposed to Tyrosol

The bioaccessibility of mycotoxins is an important factor that has to be considered when assessing the risk they pose to human health. Bioactive compounds like phenolics could play a protective role against the toxic effects of contaminants. In this work, the bioaccessible fraction of the T-2 toxin (T-2) contained in breakfast cereals and its effect on the viability of Caco-2 cells were investigated. Furthermore, the effect of tyrosol (a polyphenol abundant in EVOO) on T-2-induced cytotoxicity was evaluated in the same cell line. After standardized in vitro gastrointestinal digestion, the T-2 toxin was released from T-2-spiked breakfast cereals and further quantified by UHPLC-MS/MS. The bioaccessible fraction of T-2 was 51 ± 4%. The cell viability study was performed by pre-treating the cells for 24 h with tyrosol (25, 50 and 100 µM) and subsequently adding T-2 at 15 nM or by treating the cells with a combination of tyrosol and T-2. In the simultaneous treatment, 25 µM tyrosol prevented the toxic effects produced by the exposure to T-2 at 15 nM; however, cytotoxic effects were observed for the other combinations tested. The pre-treatment of Caco-2 cells with tyrosol did not attenuate the cytotoxic effects caused by exposure to T-2. These results suggest that tyrosol at low concentrations (25 µM) could exert a cytoprotective effect on Caco-2 cells against 15 nM T-2 when administered simultaneously with T-2. However, more studies are required to corroborate this hypothesis.

Targeted Application of Functional Foods as Immune Fitness Boosters in the Defense against Viral Infection

In recent times, the emergence of viral infections, including the SARS-CoV-2 virus, the monkeypox virus, and, most recently, the Langya virus, has highlighted the devastating effects of viral infection on human life. There has been significant progress in the development of efficacious vaccines for the prevention and control of viruses; however, the high rates of viral mutation and transmission necessitate the need for novel methods of control, management, and prevention. In recent years, there has been a shift in public awareness on health and wellbeing, with consumers making significant dietary changes to improve their immunity and overall health. This rising health awareness is driving a global increase in the consumption of functional foods. This review delves into the benefits of functional foods as potential natural means to modulate the host immune system to enhance defense against viral infections. We provide an overview of the functional food market in Europe and discuss the benefits of enhancing immune fitness in high-risk groups, including the elderly, those with obesity, and people with underlying chronic conditions. We also discuss the immunomodulatory mechanisms of key functional foods, including dairy proteins and hydrolysates, plant-based functional foods, fermentates, and foods enriched with vitamin D, zinc, and selenium. Our findings reveal four key immunity boosting mechanisms by functional foods, including inhibition of viral proliferation and binding to host cells, modulation of the innate immune response in macrophages and dendritic cells, enhancement of specific immune responses in T cells and B cells, and promotion of the intestinal barrier function. Overall, this review demonstrates that diet-derived nutrients and functional foods show immense potential to boost viral immunity in high-risk individuals and can be an important approach to improving overall immune health.

Microbiome Alterations and Alzheimer's Disease: Modeling Strategies with Transgenic Mice

In the last decade, the role of the microbiota-gut-brain axis has been gaining momentum in the context of many neurodegenerative and metabolic disorders, including Alzheimer's disease (AD) and diabetes, respectively. Notably, a balanced gut microbiota contributes to the epithelial intestinal barrier maintenance, modulates the host immune system, and releases neurotransmitters and/or neuroprotective short-chain fatty acids. However, dysbiosis may provoke immune dysregulation, impacting neuroinflammation through peripheral-central immune communication. Moreover, lipopolysaccharide or detrimental microbial end-products can cross the blood-brain barrier and induce or at least potentiate the neuropathological progression of AD. Thus, after repeated failure to find a cure for this dementia, a necessary paradigmatic shift towards considering AD as a systemic disorder has occurred. Here, we present an overview of the use of germ-free and/or transgenic animal models as valid tools to unravel the connection between dysbiosis, metabolic diseases, and AD, and to investigate novel therapeutical targets. Given the high impact of dietary habits, not only on the microbiota but also on other well-established AD risk factors such as diabetes or obesity, consistent changes of lifestyle along with microbiome-based therapies should be considered as complementary approaches.

Oleocanthal - Characterization, production, safety, functionality and in vivo evidences

Oleocanthal, OC, 2-(4-Hydroxyphenyl)ethyl(3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate, is a natural organic compound exclusively found in Olea europaea L. (Oleoaceae), such as extra virgin olive oil (EVOO). Chemically, it is considered a monophenolic secoiridoid, taking part of the validated antioxidants naturally occurring in some plant-based foods. In this review, the aim is to summarize the identity and characteristics of this molecule, where it can be obtained (isolation from the natural source or chemical synthesis), as well as the use as food component. Then, the bioavailability, safety and studies aiming to demonstrate the potential health benefits, including in vitro and in vivo animal and human studies were also discussed.

In vivo evidences of the health-promoting properties of bioactive compounds obtained from olive by-products and their use as food ingredient

Olea europaea L. is the source of virgin olive oil (VOO). During its extraction, a high amount of by-products (pomace, mill wastewaters, leaves, stones, and seeds) is originated, which possess an environmental problem. If the generation of waste cannot be prevented, its economic value must be recovered and its effects on the environment and climate change must be avoided or minimized. The bioactive compounds (e.g., phenols, pectins, peptides) of these by-product fractions are being investigated as nutraceutical due to the beneficial properties it might have. In this review, the aim is to summarize the in vivo studies carried out in animals and humans with bioactive compounds exclusively obtained from olive by-products, aiming to demonstrate the potential health benefits these products can exert, as well as to describe its use in the food industry as bioactive ingredient. Several food matrices have been fortified with olive by-products fractions, leading to an improvement of properties. Animal and human studies suggest the benefits of ingesting olive-derived products to promote health. However, the investigation until now is scarce and consequently, well-designed human studies are required in order to fully address and confirm the safety and health-promoting properties of olive oil by-products.

Evidence Supporting the Involvement of the Minority Compounds of Extra Virgin Olive Oil, through Gut Microbiota Modulation, in Some of the Dietary Benefits Related to Metabolic Syndrome in Comparison to Butter

Extra virgin olive oil (EVOO) has proven to yield a better health outcome than other saturated fats widely used in the Western diet, including a distinct dysbiosis-preventive modulation of gut microbiota. Besides its high content in unsaturated fatty acids, EVOO also has an unsaponifiable polyphenol-enriched fraction that is lost when undergoing a depurative process that gives place to refined olive oil (ROO). Comparing the effects of both oils on the intestinal microbiota of mice can help us determine which benefits of EVOO are due to the unsaturated fatty acids, which remain the same in both, and which benefits are a consequence of its minority compounds, mainly polyphenols. In this work, we study these variations after only six weeks of diet, when physiological changes are not appreciated yet but intestinal microbial alterations can already be detected. Some of these bacterial deviations correlate in multiple regression models with ulterior physiological values, at twelve weeks of diet, including systolic blood pressure. Comparison between the EVOO and ROO diets reveals that some of these correlations can be explained by the type of fat that is present in the diet, while in other cases, such as the genus Desulfovibrio, can be better understood if the antimicrobial role of the virgin olive oil polyphenols is considered.

S-(-)-Oleocanthal Ex Vivo Modulatory Effects on Gut Microbiota

Compelling evidence points to the critical role of bioactive extra-virgin olive oil (EVOO) phenolics and gut microbiota (GM) interplay, but reliable models for studying the consequences thereof remain to be developed. Herein, we report an optimized ex vivo fecal anaerobic fermentation model to study the modulation of GM by the most bioactive EVOO phenolic S-(-)-oleocanthal (OC), and impacts therefrom, focusing on OC biotransformation in the gut. This model will also be applicable for characterization of GM interactions with other EVOO phenolics, and moreover, for a broadly diverse range of bioactive natural products. The fecal fermentation media and time, and mouse type and gender, were the major factors varied and optimized to provide better understanding of GM-OC interplay. A novel resin entrapment technique (solid-phase extraction) served to selectively entrap OC metabolites, degradation products, and any remaining fraction of OC while excluding interfering complex fecal medium constituents. The effects of OC on GM compositions were investigated via shallow shotgun DNA sequencing. Robust metabolome analyses identified GM bacterial species selectively altered (population numbers/fraction) by OC. Finally, the topmost OC-affected gut bacterial species of the studied mice were compared with those known to be extant in humans and distributions of these bacteria at different human body sites. OC intake caused significant quantitative and qualitative changes to mice GM, which was also comparable with human GM. Results clearly highlight the potential positive health outcomes of OC as a prospective nutraceutical.

Host Microbiomes Influence the Effects of Diet on Inflammation and Cancer

Cancer is the second leading cause of death globally, and there is a growing appreciation for the complex involvement of diet, microbiomes, and inflammatory processes culminating in tumorigenesis. Although research has significantly improved our understanding of the various factors involved in different cancers, the underlying mechanisms through which these factors influence tumor cells and their microenvironment remain to be completely understood. In particular, interactions between the different microbiomes, specific dietary factors, and host cells mediate both local and systemic immune responses, thereby influencing inflammation and tumorigenesis. Developing an improved understanding of how different microbiomes, beyond just the colonic microbiome, can interact with dietary factors to influence inflammatory processes and tumorigenesis will support our ability to better understand the potential for microbe-altering and dietary interventions for these patients in future.

Intestinal microbiome in normal ageing, frailty and cognition decline

PURPOSE OF REVIEW

The intestinal microbiome modulates the risk of several age-related chronic diseases and syndromes, including frailty and neurodegenerative diseases. Herein we provided an update on the influence of gut microbiota on physical and cognitive performance in older age and suggest microbiota-targeted interventions for healthy ageing.

RECENT FINDINGS

Low uniqueness index of the gut microbiome and high representation of Bacteroides are independently associated with mortality in older individuals, while the centenarian microbiome is characterized by high abundance of Lactobacilli and Bifidobacteria . Frailty syndrome, sarcopenia and cognitive decline are associated with reduced faecal microbiota biodiversity, reduced abundance of bacteria able to synthetize short-chain fatty acids (SCFA), including Faecalibacterium prausnitzii , and reduced faecal butyrate levels. Dietary intervention, especially involving Mediterranean diet, and exercise training seem to be associated with improved biodiversity of the microbiota, increased capacity of SCFA synthesis and, probably, protection against the onset of frailty and cognitive decline.

SUMMARY

The gut microbiota biodiversity and composition may reflect the different ageing trajectory, but further research is needed to understand potential independent and combined effects of environmental and lifestyle factors in older adults, especially from a clinical point of view.

The gut microbiome: an overview of current trends and risks for paediatric populations

PURPOSE OF REVIEW

Gut health is an increasingly popular topic of discussion among scientists and the general population alike. As interest surrounding the gut microbiome grows, the accessibility to misinformation and unfounded gut health trends to youth is likely to emerge as a public health concern. The purpose of this review is to provide paediatricians with current information about the gut microbiome, as well as explanations and possible risks of the multitude of gut health trends that adolescents may be exposed to.

RECENT FINDINGS

The gut microbiome is implicated in overall health by playing roles in digestion, immunity and mental health. Novel microbiome-related therapies, such as faecal microbiota transplants, and the gut-brain link show the therapeutic potential of the gut microbiome. However, unproven dietary fads and trends on social media are rampant as well, such as ginger juice shots. In addition, paediatric supplements meant to target gut health are unregulated, yet are highly marketed. Improperly applying these trends and diets may result in risks of malnutrition and body image issues for impressionable children.

SUMMARY

Increased familiarity regarding the types of gut health trends and diets among young people will allow paediatricians to more effectively advise their patients about potential risks and good gut health practices. Paediatricians and caregivers serve as role models and educators with regard to children's perceptions and management of their gut and overall health.

Gut microbiota, pathogenic proteins and neurodegenerative diseases

As the world's population ages, neurodegenerative diseases (NDs) have brought a great burden to the world. However, effective treatment measures have not been found to alleviate the occurrence and development of NDs. Abnormal accumulation of pathogenic proteins is an important cause of NDs. Therefore, effective inhibition of the accumulation of pathogenic proteins has become a priority. As the second brain of human, the gut plays an important role in regulate emotion and cognition functions. Recent studies have reported that the disturbance of gut microbiota (GM) is closely related to accumulation of pathogenic proteins in NDs. On the one hand, pathogenic proteins directly produced by GM are transmitted from the gut to the central center via vagus nerve. On the other hand, The harmful substances produced by GM enter the peripheral circulation through intestinal barrier and cause inflammation, or cross the blood-brain barrier into the central center to cause inflammation, and cytokines produced by the central center cause the production of pathogenic proteins. These pathogenic proteins can produced by the above two aspects can cause the activation of central microglia and further lead to NDs development. In addition, certain GM and metabolites have been shown to have neuroprotective effects. Therefore, modulating GM may be a potential clinical therapeutic approach for NDs. In this review, we summarized the possible mechanism of NDs caused by abnormal accumulation of pathogenic proteins mediated by GM to induce the activation of central microglia, cause central inflammation and explore the therapeutic potential of dietary therapy and fecal microbiota transplantation (FMT) in NDs.

Olive oil consumption and risk of cardiovascular disease and all-cause mortality: A meta-analysis of prospective cohort studies

Background

Epidemiological studies have shown the preventive effects of olive oil consumption against cardiovascular events and all-cause deaths, but the results remain inconsistent. Herein, we performed a meta-analysis to elucidate this association.

Materials and methods

A systematical literature search was conducted in online databases (PubMed and Scopus) through July 31, 2022. Prospective cohort studies providing the risk of total cardiovascular disease (CVD) or all-cause mortality for olive oil consumption were included. Relative risks (RRs) and 95% confidence intervals (CIs) were aggregated using random-effect model.

Results

This meta-analysis included 13 studies comprising a total of 13 prospective cohorts. Compared with lower consumption, higher consumption of olive oil conferred a significantly reduced risk in CVD (RR: 0.85, 95% CI: 0.77–0.93, p < 0.001) and all-cause mortality (RR: 0.83, 95% CI: 0.77–0.90, p < 0.001). This beneficial effect was not modified by the potential confounders such as study country, sample size, follow-up duration, gender, and type of olive oil consumed. In dose-response meta-analysis, the summary RR of per 5-g/days increase in olive oil intake was 0.96 (95% CI: 0.93–0.99, p = 0.005) for CVD and 0.96 (95% CI: 0.95–0.96, p < 0.001) for all-cause mortality. Non-linear associations of olive oil intake with CVD and all-cause mortality were also identified (both p for non-linearity < 0.001), with little additional or no risk reduction observed beyond the consumption of approximately 20 g/days.

Conclusion

Olive oil consumption is inversely related to the risk of CVD and all-cause mortality. Such benefits seem to be obtained with an intake of olive oil up to 20 g/days, which deserves further exploration in future studies.

Oxidative stress and metabolic diseases: Relevance and therapeutic strategies

Metabolic syndrome (MS) is a prominent cause of death worldwide, posing a threat to the global economy and public health. A mechanism that causes the oxidation of low-density lipoproteins (LDL) is associated with metabolic abnormalities. Various processes are involved in oxidative stress (OS) of lipoprotein. Although the concept of the syndrome has been fiercely debated, this confluence of risk factors is associated with a higher chance of acquiring type 2 diabetes mellitus (T2DM) and atherosclerosis. Insulin resistance has been found to play a significant role in the progression of these metabolism-associated conditions. It causes lipid profile abnormalities, including greater sensitivity to lipid peroxidation, contributing to the increased prevalence of T2DM and atherosclerosis. This review aims to cover the most recent scientific developments in dietary OS, the consequence of metabolic disorders, and their most significant clinical manifestations (T2DM and atherosclerosis). It will also emphasize the effects of dietary approaches in alleviating OS in MS.

Dietary EVOO Polyphenols and Gut Microbiota Interaction: Are There Any Sex/Gender Influences?

Accumulating evidence indicates that regular consumption of extra virgin olive oil (EVOO), the main source of fat in the Mediterranean diet, is associated with beneficial health effects and a reduced risk of developing chronic degenerative disorders. The beneficial effects of EVOO can be attributed to its unique composition in monounsaturated fats and phenolic compounds that provide important antioxidant, anti-inflammatory, and immune-modulating activities. On the other hand, it is well known that the gut microbiota has several important roles in normal human physiology, and its composition can be influenced by a multitude of environmental and lifestyle factors, among which dietary components play a relevant role. In the last few years, the two-way interaction between polyphenols, including those in EVOO, and the gut microbiota, i.e., the modulation of the microbiota by polyphenols and that of polyphenol metabolism and bioavailability by the microbiota, has attracted growing attention, being potentially relevant to explain the final effects of polyphenols, as well as of the microbiota profile. Furthermore, sex and gender can affect dietary habits, polyphenol intake, and nutrient metabolism. Lastly, it has been recently suggested that differences in gut microbiota composition could be involved in the unequal incidence of metabolic diseases observed between women and men, due to sex-dependent effects on shaping gut microbiota profiles according to diet. This review summarizes the most recent studies on the relationship between EVOO polyphenols and the gut microbiota, taking into account possible influences of sex and gender in modulating such an interaction.

Chemoprevention effect of the Mediterranean diet on colorectal cancer: Current studies and future prospects

Colorectal cancer (CRC) is the third most common cancer and the second most deadly cancer worldwide. Nevertheless, more than 70% of CRC cases are resulted from sporadic tumorigenesis and are not inherited. Since adenoma-carcinoma development is a slow process and may take up to 20 years, diet-based chemoprevention could be an effective approach in sporadic CRC. The Mediterranean diet is an example of a healthy diet pattern that consists of a combination of nutraceuticals that prevent several chronic diseases and cancer. Many epidemiological studies have shown the correlation between adherence to the Mediterranean diet and low incidence of CRC. The goal of this review is to shed the light on the anti-inflammatory and anti-colorectal cancer potentials of the natural bioactive compounds derived from the main foods in the Mediterranean diet.

Impact of alcohol-induced intestinal microbiota dysbiosis in a rodent model of Alzheimer's disease

Introduction: Alzheimer's disease (AD) is a devastating neurodegenerative disorder. While genetics are important in the development of AD, environment and lifestyle are also important factors influencing AD. One such lifestyle factor is alcohol consumption. Unhealthy and excessive chronic alcohol consumption is associated with a greater risk of all types of dementia, especially AD. Alcohol consumption has numerous effects on the body, including alterations to the intestinal microbiota (dysbiosis) and intestinal barrier dysfunction (leakiness and intestinal hyperpermeability), with evidence indicating that inflammation resulting from dysbiosis and barrier dysfunction can promote neuroinflammation impacting brain structure and function. Objective: This study sought to determine the impact of alcohol-induced dysbiosis and barrier dysfunction on AD-like behavior and brain pathology using a transgenic rodent model of AD (3xTg-AD). Methods: Alcohol (20%) was administered to 3xTg-AD mice in the drinking water for 20 weeks. Intestinal (stool) microbiota, intestinal barrier permeability, systemic inflammation (IL-6), behavior, and AD pathology (phosphorylated tau and β-amyloid), and microglia were examined. Results: Alcohol consumption changed the intestinal microbiota community (dysbiosis) and increased intestinal barrier permeability in both control and 3xTg-AD mice (oral/urine sugar test and lipopolysaccharide-binding protein (LBP)). However, alcohol consumption did not influence serum IL-6, behavior, or β-amyloid, phosphorylated tau, or microglia in 3xTg-AD mice. Important differences in genotype and sex were noted. Conclusion: Alcohol-induced microbiota dysbiosis and intestinal barrier dysfunction did not exacerbate behavior or AD-like brain pathology in the 3xTg-AD mouse model of AD which could, in part, be the result of a lack of systemic inflammation.

Neuroprotective Natural Products’ Regulatory Effects on Depression via Gut–Brain Axis Targeting Tryptophan

L-tryptophan (Trp) contributes to regulating bilateral communication of the gut–brain axis. It undergoes three major metabolic pathways, which lead to formation of kynurenine, serotonin (5-HT), and indole derivatives (under the control of the microbiota). Metabolites from the principal Trp pathway, kynurenic acid and quinolinic acid, exhibit neuroprotective activity, while picolinic acid exhibits antioxidant activity, and 5-HT modulates appetite, sleep cycle, and pain. Abnormality in Trp plays crucial roles in diseases, including depression, colitis, ulcer, and gut microbiota-related dysfunctions. To address these diseases, the use of natural products could be a favorable alternative because they are a rich source of compounds that can modulate the activity of Trp and combat various diseases through modulating different signaling pathways, including the gut microbiota, kynurenine pathway, and serotonin pathway. Alterations in the signaling cascade pathways via different phytochemicals may help us explore the deep relationships of the gut–brain axis to study neuroprotection. This review highlights the roles of natural products and their metabolites targeting Trp in different diseases. Additionally, the role of Trp metabolites in the regulation of neuroprotective and gastroprotective activities is discussed. This study compiles the literature on novel, potent neuroprotective agents and their action mechanisms in the gut–brain axis and proposes prospective future studies to identify more pharmaceuticals based on signaling pathways targeting Trp.

Protective effects of camellia and olive oils against cognitive impairment via gut microbiota-brain communication in rats

Food intake influences neurofunction via the gut microbiota-brain axis. Monounsaturated fatty acid (MUFA) consumption is highly associated with neuroprotection; the mechanism behind the effects of olive oil and camellia oil on gut microbiota remains unclear. In this study, the objective was to compare the neuroprotective role of oleic acid-rich camellia oil and olive oil against AlCl₃-induced mild cognitive impairment (MCI) in rats. Morris water maze tests revealed that learning and memory capacities improved in AlCl₃-induced rats subjected to camellia oil administration better than olive oil treatment. Moreover, the results showed that the camellia oil- and olive oil-treated AlCl₃-induced rat groups had significantly reduced oxidative stress and inflammatory cytokines. Notably, Spearman correlation analysis indicated that the inflammatory cytokines negatively correlated with the microbial strains (Bacteroides pectinophilus_group and Blautia) in response to camellia oil administration. Furthermore, Ruminococcaceae_UCG014 abundance was significantly enhanced by camellia oil intake, which was highly positively associated with antioxidant activity expression. In conclusion, the novel data suggest that the outcomes of camellia oil consumption were superior to those of olive oil intake as camellia oil may have a beneficial effect on MCI protection and improvement through the gut microbiota-brain communication.

Extra Virgin Olive Oil Reduces Gut Permeability and Metabolic Endotoxemia in Diabetic Patients

BACKGROUND

Extra virgin olive oil (EVOO) improves post-prandial glycemia, but the underlying mechanism has not been fully elucidated. We tested the hypothesis that EVOO improves post-prandial glycemia by reducing gut permeability-derived low-grade endotoxemia.

METHODS

Serum levels of lipopolysaccharides (LPS), zonulin, a marker of gut permeability, glucose, insulin and glucagon-like peptide 1 (GLP1) were measured in 20 patients with impaired fasting glucose (IFG) and 20 healthy subjects (HS) matched for sex and age. The same variables were measured in IFG patients (n = 20) and HS (n = 20) before and after a Mediterranean diet with 10 g EVOO added or not (n = 20) or in IFG patients (n = 20) before and after intake of 40 g chocolate with EVOO added or not.

RESULTS

Compared to HS, IFG had higher levels of LPS and zonulin. In HS, meal intake was associated with a significant increase of blood glucose, insulin, and GLP1 with no changes of blood LPS and zonulin. Two hours after a meal intake containing EVOO, IFG patients showed a less significant increase of blood glucose, a more marked increase of blood insulin and GLP1 and a significant reduction of LPS and zonulin compared to IFG patients not given EVOO. Correlation analysis showed that LPS directly correlated with blood glucose and zonulin and inversely with blood insulin. Similar findings were detected in IFG patients given a chocolate added or without EVOO.

CONCLUSION

Addition of EVOO to a Mediterranean diet or chocolate improves gut permeability and low-grade endotoxemia.

Association Between the EAT-Lancet Diet Pattern and Risk of Type 2 Diabetes: A Prospective Cohort Study

Background:

The EAT-Lancet Commission has promulgated a sustainable dietary guideline and recommended that it was designed to improve the human health and support environmental sustainability.

Objective:

This research was designed to explore the association between this healthy diet pattern (EAT-Lancet diet pattern, EAT-LDP) and risk of type 2 diabetes (T2D).

Methods:

Between 2006 and 2010, a total of 59,849 participants from the UK Biobank without diabetes, cardiovascular disease, or cancers were included at baseline. The EAT-LDP score was constructed on the sum of 14 food components and then categorized into three tertiles. Multivariable Cox proportional hazards regression models were conducted to explore the association between EAT-LDP score and the risk of incident T2D. A mediation analysis was also implemented to disentangle the role of body mass index (BMI) and waist circumference in the relationship between EAT-LDP score and T2D.

Results:

During a median follow-up of 10 years, 2,461 incident T2D cases were recorded. In analyses that compared tertile 3 of the EAT-LDP score (highest) with tertile 1 (lowest), the hazard ratio (HR) for T2D was 0.81 (95% CI: 0.72–0.90) after adjusting for sociodemographic status and health-related factors. Participants who reported a one-point increase in the diet score were associated with a 6% decrease in risk of T2D (HR: 0.94, 95% CI: 0.91–0.97). A significant indirect association was observed between the EAT-LDP score and T2D (β: 0.66, 95% CI: 0.65–0.67), indicating that 44% of the association of EAT-LDP score with T2D was mediated by BMI. Additionally, 40% of the association of EAT-LDP score with T2D was mediated by waist circumference was also observed.

Conclusions:

Our findings indicate that a higher adherence to EAT-LDP contributes to lower risk of T2D. Further independent validation is needed to be conducted before applying the EAT-LDP to inform dietary guidelines.

Mediterranean diet score is associated with greater allocentric processing in the EPAD LCS cohort: A comparative analysis by biogeographical region

Background: Adherence to the Mediterranean diet (MedDiet), a primarily plant-based eating pattern, has been associated with lower dementia incidence. Much of the research has focused on Alzheimer's disease (AD) dementia and mild cognitive impairment (MCI), with less research looking at the preclinical symptomatically silent stages that pre-empt MCI and AD dementia. Although there is evidence from studies conducted globally, no studies have compared the effects of the MedDiet within and outside of the Mediterranean region in one cohort. Methods: Our study explored cross-sectional and longitudinal associations between MedDiet and cognition in the pan-European EPAD LCS, comparing those living within and outside of the Mediterranean region (as classified by European Union biogeographical definitions). After deriving MEDAS scores to quantify adherence to the MedDiet, we used linear regression and linear mixed effects models to test for associations between the MEDAS score and cognitive function measured by the Four Mountains Test (FMT) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). We additionally calculated MEDAS continuous and PYRAMID scores to provide alternative measures of MedDiet adherence. Results: We included 1826 participants, mean age 65.69 (±7.42) years, majority female (56.2%) with family history (65.8%) and minority APOEε4 carriers (38.9%). Higher MEDAS scores were associated with better performance on the FMT both cross-sectionally (n = 1,144, ß: -0.11, SE: 0.04, p = 0.007) and longitudinally (slope: 0.10, 95% CI: 0.04-0.17, p: 0.002). The effect was marginally greater in the Mediterranean region in the cross-sectional analysis, with a stronger effect emerging longitudinally. In exploratory analyses, the association between MEDAS and FMT scores was only seen in female participants. A sensitivity analysis excluding Toulouse and Perugia, as cities near, but not within, the biogeographical region, found significant associations between higher MEDAS and MEDAS continuous scores, and a number of RBANS total and index scores. Conclusion: MedDiet adherence is associated with better FMT scores, with effects seen most strongly in the Mediterranean region from longitudinal data. Our sensitivity analysis suggested a more global cognitive benefit of MedDiet adherence. This study highlights the need to further explore for whom and for what brain health outcomes the MedDiet confers benefit. This evidence would identify a window of opportunity in the life-course to maximise the benefit and better inform public health campaigns and patient-level interventions.

Mediterranean, DASH, and MIND Dietary Patterns and Cognitive Function: The 2-Year Longitudinal Changes in an Older Spanish Cohort

Background and Aims: Plant-forward dietary patterns have been associated with cardiometabolic health benefits, which, in turn, have been related to cognitive performance with inconsistent findings. The objective of this study was to examine the relationship between baseline adherence to three a priori dietary patterns (Mediterranean, DASH, and MIND diets) with 2-year changes in cognitive performance in older adults with overweight or obesity and high cardiovascular disease risk. Methods: A prospective cohort analysis was conducted within the PREDIMED-Plus trial, involving 6,647 men and women aged 55-75 years with overweight or obesity and metabolic syndrome. Using a validated, semiquantitative 143-item food frequency questionnaire completed at baseline, the dietary pattern adherence scores were calculated. An extensive neuropsychological test battery was administered at baseline and 2-year follow-up. Multivariable-adjusted linear regression models were used to assess associations between 2-year changes in cognitive function z-scores across tertiles of baseline adherence to the a priori dietary patterns. Results: Adherence to the Mediterranean diet at baseline was associated with 2-year changes in the general cognitive screening Mini-Mental State Examination (MMSE, β: 0.070; 95% CI: 0.014, 0.175, P-trend = 0.011), and two executive function-related assessments: the Trail Making Tests Part A (TMT-A, β: -0.054; 95% CI: -0.110, - 0.002, P-trend = 0.047) and Part B (TMT-B, β: -0.079; 95% CI: -0.134, -0.024, P-trend = 0.004). Adherence to the MIND diet was associated with the backward recall Digit Span Test assessment of working memory (DST-B, β: 0.058; 95% CI: 0.002, 0.114, P-trend = 0.045). However, higher adherence to the DASH dietary pattern was not associated with better cognitive function over a period of 2 years. Conclusion: In older Spanish individuals with overweight or obesity and at high cardiovascular disease risk, higher baseline adherence to the Mediterranean dietary pattern may be associated with better cognitive performance than lower adherence over a period of 2 years.

Potential of olive oil and its phenolic compounds as therapeutic intervention against colorectal cancer: a comprehensive review

Colorectal cancer (CRC) is one of the major causes of death across the world and incidence rate of CRC increasing alarmingly each passing year. Diet, genomic anomalies, inflammation and deregulated signalling pathways are among the major causes of CRC. Because of numerous side effects of CRC therapies available now, researchers all over the world looking for alternative treatment/preventive strategy with lesser/no side effects. Olive oil which is part of Mediterranean diet contains numerous phenolic compounds that fight against free radicals and inflammation and also well-known for protective role against CRC. The current review focused on the recent evidences where olive oil and its phenolic compounds such as hydroxytyrosol, oleuropein and oleocanthal showed activities against CRC as well to analyse the cellular and molecular signalling mechanism through which these compounds act on. These compounds shown to combat CRC by reducing proliferation, migration, invasion and angiogenesis through regulation of numerous signalling pathways including MAPK pathway, PI3K-Akt pathway and Wnt/β-catenin pathway and at the same time, induce apoptosis in different CRC model. However, further research is an absolute necessity to establish these compounds as nutritional supplements and develop therapeutic strategy in CRC.

Association of Gut Microbiome Dysbiosis with Neurodegeneration: Can Gut Microbe-Modifying Diet Prevent or Alleviate the Symptoms of Neurodegenerative Diseases?

The central nervous system was classically perceived as anatomically and functionally independent from the other visceral organs. But in recent decades, compelling evidence has led the scientific community to place a greater emphasis on the role of gut microbes on the brain. Pathological observations and early gastrointestinal symptoms highlighted that gut dysbiosis likely precedes the onset of cognitive deficits in Alzheimer's disease (AD) and Parkinson's disease (PD) patients. The delicate balance in the number and functions of pathogenic microbes and alternative probiotic populations is critical in the modulation of systemic inflammation and neuronal health. However, there is limited success in restoring healthy microbial biodiversity in AD and PD patients with general probiotics interventions and fecal microbial therapies. Fortunately, the gut microflora is susceptible to long-term extrinsic influences such as lifestyle and dietary choices, providing opportunities for treatment through comparatively individual-specific control of human behavior. In this review, we examine the impact of restrictive diets on the gut microbiome populations associated with AD and PD. The overall evidence presented supports that gut dysbiosis is a plausible prelude to disease onset, and early dietary interventions are likely beneficial for the prevention and treatment of progressive neurodegenerative diseases.

Olive Polyphenols: Antioxidant and Anti-Inflammatory Properties

Oxidative stress and inflammation triggered by increased oxidative stress are the cause of many chronic diseases. The lack of anti-inflammatory drugs without side-effects has stimulated the search for new active substances. Plant-derived compounds provide new potential anti-inflammatory and antioxidant molecules. Natural products are structurally optimized by evolution to serve particular biological functions, including the regulation of endogenous defense mechanisms and interaction with other organisms. This property explains their relevance for infectious diseases and cancer. Recently, among the various natural substances, polyphenols from extra virgin olive oil (EVOO), an important element of the Mediterranean diet, have aroused growing interest. Extensive studies have shown the potent therapeutic effects of these bioactive molecules against a series of chronic diseases, such as cardiovascular diseases, diabetes, neurodegenerative disorders and cancer. This review begins from the chemical structure, abundance and bioavailability of the main EVOO polyphenols to highlight the effects and the possible molecular mechanism(s) of action of these compounds against inflammation and oxidation, in vitro and in vivo. In addition, the mechanisms of inhibition of molecular signaling pathways activated by oxidative stress by EVOO polyphenols are discussed, together with their possible roles in inflammation-mediated chronic disorders, also taking into account meta-analysis of population studies and clinical trials.

Mediterranean, DASH, and MIND Dietary Patterns and Cognitive Function: The 2-Year Longitudinal Changes in an Older Spanish Cohort

Background and Aims: Plant-forward dietary patterns have been associated with cardiometabolic health benefits, which, in turn, have been related to cognitive performance with inconsistent findings. The objective of this study was to examine the relationship between baseline adherence to three a priori dietary patterns (Mediterranean, DASH, and MIND diets) with 2-year changes in cognitive performance in older adults with overweight or obesity and high cardiovascular disease risk. Methods: A prospective cohort analysis was conducted within the PREDIMED-Plus trial, involving 6,647 men and women aged 55-75 years with overweight or obesity and metabolic syndrome. Using a validated, semiquantitative 143-item food frequency questionnaire completed at baseline, the dietary pattern adherence scores were calculated. An extensive neuropsychological test battery was administered at baseline and 2-year follow-up. Multivariable-adjusted linear regression models were used to assess associations between 2-year changes in cognitive function z-scores across tertiles of baseline adherence to the a priori dietary patterns. Results: Adherence to the Mediterranean diet at baseline was associated with 2-year changes in the general cognitive screening Mini-Mental State Examination (MMSE, β: 0.070; 95% CI: 0.014, 0.175, P-trend = 0.011), and two executive function-related assessments: the Trail Making Tests Part A (TMT-A, β: -0.054; 95% CI: -0.110, - 0.002, P-trend = 0.047) and Part B (TMT-B, β: -0.079; 95% CI: -0.134, -0.024, P-trend = 0.004). Adherence to the MIND diet was associated with the backward recall Digit Span Test assessment of working memory (DST-B, β: 0.058; 95% CI: 0.002, 0.114, P-trend = 0.045). However, higher adherence to the DASH dietary pattern was not associated with better cognitive function over a period of 2 years. Conclusion: In older Spanish individuals with overweight or obesity and at high cardiovascular disease risk, higher baseline adherence to the Mediterranean dietary pattern may be associated with better cognitive performance than lower adherence over a period of 2 years.