Diet and the microbiota - gut - brain-axis: a primer for clinical nutrition

Unveiling the neuroprotective impact of virgin olive oil ingestion via the microbiota-gut-brain axis

The gut-brain axis, a complex system of two-way communication between both organs, plays a key role in overall health. This comprehensive review explores the possible neuromodulatory effects upon consumption of virgin olive oil (VOO) via changes in the gut microbiota. The components found in VOO, such as polyphenols and monounsaturated fatty acids, and their function in influencing the composition of the gut microbiota, focusing on those known to possess neuroactive characteristics, based on a thorough analysis of the literature were investigated. Studies suggest that these compounds, such as hydroxytyrosol and ferulic acid, may protect against neuronal death and inhibit amyloid-β plaques (Aβ) formation. Furthermore, preclinical and clinical research indicates that VOO may promote the growth of beneficial bacteria, such as Lactobacillus and Bifidobacterium, and increase the production of short-chain fatty acids (SCFAs). These changes could be related to improved cognitive function, mood regulation, and neuroprotection. However, limitations of these studies (short duration of studies, the variability in VOO composition and the lack of standardized methodologies) need to be overcome. Furthermore, the limited number of human trials and incomplete understanding of the gut-brain axis make it difficult to establish causality and clinical application of the findings. For this reason, future research should focus on long-term clinical trials with larger cohorts, standardised characterisation of VOO and on exploring the synergistic effects with other dietary components. Furthermore, mechanistic studies should aim to uncover the molecular pathways involved in the gut-brain axis to develop specific dietary interventions for neurological and neurodegenerative disorders.

Effectiveness of the SYNCHRONIZE + Brief Intervention in Improving Mediterranean Diet Adherence, Nutritional Quality and Intake Pattern in Persons with Fibromyalgia and Chronic Fatigue Syndrome

BACKGROUND

Multidisciplinary lifestyle interventions are being researched to treat fibromyalgia. However, the impact of nutrition as a key treatment component is little studied. This study aimed to evaluate the effectiveness of the SYNCHRONIZE + lifestyle multidisciplinary intervention in improving adherence to the Mediterranean diet, nutrition quality and dietary intake pattern in persons with fibromyalgia and chronic fatigue syndrome.

METHODS

A pragmatic randomized clinical trial was conducted in primary care. Data were collected using the 17-item energy-restricted Mediterranean Adherence Screener (er-MEDAS), the food frequency questionnaire (sFFQ) and the 24 h recall questionnaire (24 HR), in addition to chrono-nutritional, anthropometric, and body composition data, at baseline and 3-, 6-, and 12- month follow-up visits, and statistically analyzed.

RESULTS

A total of 158 participants were evaluated. Results showed the effectiveness of the intervention in improving adherence to the Mediterranean diet. The adherence depended on the group-time interaction being positive and significant at 3 and 6 months post-intervention in the INT group and on the participant age and educational level. Specifically, the intake of legumes, fruits, vegetables, nuts and blue fish was increased, while the intake of sweets and pastries, butter and cream and red and processed meat was reduced. Furthermore, the intake of chips and candies was also reduced, and the consumption of fermented food (yogurts, cheese, kefir) increased. Thus, general diet quality improved. Interestingly, the intake of key nutrients such as protein and iron increased. Furthermore, the number of night eaters was decreased significantly. Muscle mass index was also improved in the intervention group. These results were maintained in the medium to long term.

CONCLUSION

SYNCHRONIZE + is a brief, low-cost, multidisciplinary intervention effective in improving adherence to the Mediterranean diet and improving nutritional and dietary intake patterns in persons with fibromyalgia and chronic fatigue syndrome. Further evaluation of the effect on quality of life and symptoms is needed.

Fibre & fermented foods: differential effects on the microbiota-gut-brain axis

The ability to manipulate brain function through the communication between the microorganisms in the gastrointestinal tract and the brain along the gut-brain axis has emerged as a potential option to improve cognitive and emotional health. Dietary composition and patterns have demonstrated a robust capacity to modulate the microbiota-gut-brain axis. With their potential to possess pre-, pro-, post-, and synbiotic properties, dietary fibre and fermented foods stand out as potent shapers of the gut microbiota and subsequent signalling to the brain. Despite this potential, few studies have directly examined the mechanisms that might explain the beneficial action of dietary fibre and fermented foods on the microbiota-gut-brain axis, thus limiting insight and treatments for brain dysfunction. Herein, we evaluate the differential effects of dietary fibre and fermented foods from whole food sources on cognitive and emotional functioning. Potential mediating effects of dietary fibre and fermented foods on brain health via the microbiota-gut-brain axis are described. Although more multimodal research that combines psychological assessments and biological sampling to compare each food type is needed, the evidence accumulated to date suggests that dietary fibre, fermented foods, and/or their combination within a psychobiotic diet can be a cost-effective and convenient approach to improve cognitive and emotional functioning across the lifespan.

Modulatory effects of traditional Chinese medicines on gut microbiota and the microbiota-gut-x axis

The gut microbiota offers numerous benefits to the human body, including the promotion of nutrient absorption, participation in metabolic processes, and enhancement of immune function. Recent studies have introduced the concept of the gut-organ axis, which encompasses interactions such as the gut-brain axis, gut-liver axis, and gut-lung axis. This concept underscores the complex interplay between gut microbiota and various organs and tissues, including the brain, heart, lungs, liver, kidneys, muscles, and bones. Growing evidence indicates that gut microbiota can influence the onset and progression of multi-organ system diseases through their effects on the gut-organ axis. Traditional Chinese medicine has demonstrated significant efficacy in regulating the gastrointestinal system, leveraging its unique advantages. Considerable advancements have been made in understanding the role of gut microbiota and the gut-organ axis within the mechanisms of action of traditional Chinese medicine. This review aims to elucidate the roles of gut microbiota and the gut-organ axis in human health, explore the potential connections between traditional Chinese medicine and gut microbiota, and examine the therapeutic effects of traditional Chinese medicine on the microbiota-gut-organ axis. Furthermore, the review addresses the limitations and challenges present in current research while proposing potential directions for future investigations in this area.

Unraveling the gut-brain axis: the impact of steroid hormones and nutrition on Parkinson's disease

This comprehensive review explores the intricate relationship between nutrition, the gut microbiome, steroid hormones, and Parkinson's disease within the context of the gut-brain axis. The gut-brain axis plays a pivotal role in neurodegenerative diseases like Parkinson's disease, encompassing diverse components such as the gut microbiota, immune system, metabolism, and neural pathways. The gut microbiome, profoundly influenced by dietary factors, emerges as a key player. Nutrition during the first 1000 days of life shapes the gut microbiota composition, influencing immune responses and impacting both child development and adult health. High-fat, high-sugar diets can disrupt this delicate balance, contributing to inflammation and immune dysfunction. Exploring nutritional strategies, the Mediterranean diet's anti-inflammatory and antioxidant properties show promise in reducing Parkinson's disease risk. Microbiome-targeted dietary approaches and the ketogenic diet hold the potential in improving brain disorders. Beyond nutrition, emerging research uncovers potential interactions between steroid hormones, nutrition, and Parkinson's disease. Progesterone, with its anti-inflammatory properties and presence in the nervous system, offers a novel option for Parkinson's disease therapy. Its ability to enhance neuroprotection within the enteric nervous system presents exciting prospects. The review addresses the hypothesis that α-synuclein aggregates originate from the gut and may enter the brain via the vagus nerve. Gastrointestinal symptoms preceding motor symptoms support this hypothesis. Dysfunctional gut-brain signaling during gut dysbiosis contributes to inflammation and neurotransmitter imbalances, emphasizing the potential of microbiota-based interventions. In summary, this review uncovers the complex web of interactions between nutrition, the gut microbiome, steroid hormones, and Parkinson's disease within the gut-brain axis framework. Understanding these connections not only offers novel therapeutic insights but also illuminates the origins of neurodegenerative diseases such as Parkinson's disease.

Therapeutic potential of the ketogenic diet: A metabolic switch with implications for neurological disorders, the gut-brain axis, and cardiovascular diseases

The Ketogenic Diet (KD) is a dietary regimen that is low in carbohydrates, high in fats, and contains adequate protein. It is designed to mimic the metabolic state of fasting. This diet triggers the production of ketone bodies through a process known as ketosis. The primary objective of KD is to induce and sustain ketosis, which has been associated with numerous health benefits. Recent research has uncovered promising therapeutic potential for KD in the treatment of various diseases. This includes evidence of its effectiveness as a dietary strategy for managing intractable epilepsy, a form of epilepsy that is resistant to medication. We are currently assessing the efficacy and safety of KD through laboratory and clinical studies. This review focuses on the anti-inflammatory properties of the KD and its potential benefits for neurological disorders and the gut-brain axis. We also explore the existing literature on the potential effects of KD on cardiac health. Our aim is to provide a comprehensive overview of the current knowledge in these areas. Given the encouraging preliminary evidence of its therapeutic effects and the growing understanding of its mechanisms of action, randomized controlled trials are warranted to further explore the rationale behind the clinical use of KD. These trials will ultimately enhance our understanding of how KD functions and its potential benefits for various health conditions. We hope that our research will contribute to the body of knowledge in this field and provide valuable insights for future studies.

Fecal microbiota transplantation ameliorates high-fat diet-induced memory impairment in mice

Gut dysbiosis is linked to metabolic and neurodegenerative diseases and comprises a plausible link between high-fat diet (HFD) and brain dysfunction. Here we show that gut microbiota modulation by either antibiotic treatment for 5 weeks or a brief 3-day fecal microbiota transplantation (FMT) regimen from low-fat (control) diet-fed mice decreased weight gain, adipose tissue hypertrophy, and glucose intolerance induced by HFD in C57BL/6 male mice. Notably, gut microbiota modulation by FMT completely reversed impaired recognition memory induced by HFD, whereas modulation by antibiotics had less pronounced effect. Improvement in recognition memory by FMT was accompanied by decreased HFD-induced astrogliosis in the hippocampal cornu ammonis region. Gut microbiome composition analysis indicated that HFD diminished microbiota diversity compared to control diet, whereas FMT partially restored the phyla diversity. Our findings reinforce the role of the gut microbiota on HFD-induced cognitive impairment and suggest that modulating the gut microbiota may be an effective strategy to prevent metabolic and cognitive dysfunction associated with unfavorable dietary patterns.

Influence of human gut microbiome on the healthy and the neurodegenerative aging

The gut microbiome plays a crucial role in host health throughout the lifespan by influencing brain function during aging. The microbial diversity of the human gut microbiome decreases during the aging process and, as a consequence, several mechanisms increase, such as oxidative stress, mitochondrial dysfunction, inflammatory response, and microbial gut dysbiosis. Moreover, evidence indicates that aging and neurodegeneration are closely related; consequently, the gut microbiome may serve as a novel marker of lifespan in the elderly. In this narrative study, we investigated how the changes in the composition of the gut microbiome that occur in aging influence to various neuropathological disorders, such as mild cognitive impairment (MCI), dementia, Alzheimer's disease (AD), and Parkinson's disease (PD); and which are the possible mechanisms that govern the relationship between the gut microbiome and cognitive impairment. In addition, several studies suggest that the gut microbiome may be a potential novel target to improve hallmarks of brain aging and to promote healthy cognition; therefore, current and future therapeutic interventions have been also reviewed.

Novel digital-based approach for evaluating wine components' intake: A deep learning model to determine red wine volume in a glass from single-view images

Estimation of wine components' intake (polyphenols, alcohol, etc.) through Food Frequency Questionnaires (FFQs) may be particularly inaccurate. This paper reports the development of a deep learning (DL) method to determine red wine volume from single-view images, along with its application in a consumer study developed via a web service. The DL model demonstrated satisfactory performance not only in a daily lifelike images dataset (mean absolute error = 10 mL), but also in a real images dataset that was generated through the consumer study (mean absolute error = 26 mL). Based on the data reported by the participants in the consumer study (n = 38), average red wine volume in a glass was 114 ± 33 mL, which represents an intake of 137-342 mg of total polyphenols, 11.2 g of alcohol, 0.342 g of sugars, among other components. Therefore, the proposed method constitutes a diet-monitoring tool of substantial utility in the accurate assessment of wine components' intake.

Diet Quality and Resilience through Adulthood: A Cross-Sectional Analysis of the WELL for Life Study

Despite evidence suggesting the importance of psychological resilience for successful aging, little is known about the relationship between diet quality and resilience at different ages. Our study aims to examine the association between diet quality and resilience across the stages of adulthood. Using Stanfords' WELL for Life (WELL) survey data, we conducted a cross-sectional study of diet quality, resilience, sociodemographic, perceived stress, lifestyle, and mental health factors among 6171 Bay Area adults. Diet quality was measured by the WELL Diet Score, which ranges from 0-120. A higher score indicates a better diet quality. Linear regression analysis was used to evaluate the association between the WELL Diet Score and overall resilience and within the following age groups: early young (18-24), late young (25-34), middle (35-49), and late adulthood (≥50). To test whether these associations varied by age groups, an age group by resilience interaction term was also examined. In the fully adjusted model, the WELL Diet Score was positively and significantly associated with overall resilience (all ages (β = 1.2 ± sd: 0.2, p < 0.001)) and within each age group (early young (β = 1.1 ± sd: 0.3, p < 0.001); late young (β = 1.2 ± sd: 0.3, p < 0.001); middle (β = 0.9 ± sd: 0.3, p < 0.001); and late adulthood (β = 1.0 ± sd: 0.3, p < 0.001)). Young adults demonstrated the strongest associations between diet quality and resilience. However, there were no significant age-by-resilience interactions. Diet quality may be positively associated with resilience at all stages of adulthood. Further research is needed to determine whether assessing and addressing resilience could inform the development of more effective dietary interventions, particularly in young adults.

Unveiling the neuroprotective properties of isoflavones: current evidence, molecular mechanisms and future perspectives

Neurodegenerative diseases encompass a wide range of debilitating and incurable brain disorders characterized by the progressive deterioration of the nervous system's structure and function. Isoflavones, which are naturally occurring polyphenolic phytochemicals, have been found to regulate various cellular signaling pathways associated with the nervous system. The main objective of this comprehensive review is to explore the neuroprotective effects of isoflavones, elucidate the underlying mechanisms, and assess their potential for treating neurodegenerative disorders. Relevant data regarding isoflavones and their impact on neurodegenerative diseases were gathered from multiple library databases and electronic sources, including PubMed, Google Scholar, Web of Science, and Science Direct. Numerous isoflavones, including genistein, daidzein, biochanin A, and formononetin, have exhibited potent neuroprotective properties against various neurodegenerative diseases. These compounds have been found to modulate neurotransmitters, which in turn contributes to their ability to protect against neurodegeneration. Both in vitro and in vivo experimental studies have provided evidence of their neuroprotection mechanisms, which involve interactions with estrogenic receptors, antioxidant effects, anti-inflammatory properties, anti-apoptotic activity, and modulation of neural plasticity. This review aims to provide current insights into the neuroprotective characteristics of isoflavones and shed light on their potential therapeutic applications in future clinical scenarios.

Immune consequences of exercise in hypoxia: A narrative review

Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type, dose (frequency/duration, intensity), and individual characteristics. Similarly, reduced availability of ambient oxygen (hypoxia) modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia. How combined exercise and hypoxia (e.g., high-altitude training) sculpts immune responses is not well understood, although such combinations are becoming increasingly popular. Therefore, in this paper, we summarize the impact on immune responses of exercise and of hypoxia, both independently and together, with a focus on specialized cells in the innate and adaptive immune system. We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia, then we discuss how they may be modulated by nutritional strategies. Mitochondrial, antioxidant, and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism, resilience, and overall immune functions by regulating the survival, differentiation, activation, and migration of immune cells. This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions. Appropriate acclimatization, training, and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state.

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.

The Role of Diet in the Management of Irritable Bowel Syndrome: A Comprehensive Review

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder that has a significant impact on the general population. The suboptimal medical treatments available for IBS contribute to its large economic burden. The pathophysiology of IBS is complex, and treatments often focus on managing specific symptoms. Many individuals with IBS associate their symptoms with specific food intake, leading to increased scientific research on the role of diet in managing IBS. Dietary management has become a crucial aspect of IBS treatment, with initial recommendations focusing on adopting a healthy eating pattern and lifestyle. This comprehensive review aims to synthesise the current literature on the impact of diet on IBS, exploring various dietary approaches to managing IBS, including the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet, gluten-free diet, Mediterranean diet, and tritordeum-based diet. It presents evidence from both experimental and observational studies and summarises the underlying dietary triggers in IBS, including gut microbiota dysbiosis, visceral hypersensitivity, and immune activation. In addition, it explores the efficacy and limitations of the key diet and lifestyle recommendations provided by dietary guidelines and scientific literature, highlighting the importance of individualised dietary strategies tailored to the unique needs of different types of IBS patients. By elucidating the complex interplay between diet and IBS pathophysiology, this review provides valuable insights into optimising dietary management approaches for improving symptom control and enhancing the quality of life for individuals with IBS.

Alterations in gut microbiota caused by major depressive disorder or a low FODMAP diet and where they overlap

Beneficial changes in microbiota observed in individuals with a major depressive disorder (MDD) may be initiated with a low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) elimination diet. Academic Search Ultimate, APA PsychINFO, Cochrane Library, MEDLINE, Scopus and Web of Science were searched for original research documenting differences in microbiota in MDD or changes with a low FODMAP diet in adults (age 18 years +). Studies with fecal microbiota, 16 s RNA sequencing and QIIME pipelines were included. Studies using antibiotics, probiotics, and medications such as antidepressants were excluded. Additionally, studies based on a single gender were excluded as gender impacts microbiota changes in MDD. Four studies addressed differences in microbiota with MDD and another four assessed shifts occurring with a low FODMAP diet. The abundance of Bacteroidetes, Bacteroidaceae and Bacteroides were lower in individuals with MDD but increased with a low FODMAP diet. Abundance of Ruminoccaceae was lower and Bilophila was higher with both a low FODMAP diet and MDD. These results provide preliminary evidence that a low FODMAP diet might drive changes in microbiota that also benefit people with MDD. Further research to assess whether a low FODMAP diet can treat MDD through modification of targeted microbiota is warranted.

Effect of Pilates exercises on symptoms of irritable bowel syndrome in women: a randomized controlled trial

Objective

The treatment of irritable bowel syndrome (IBS) is challenging, calling for therapeutic strategies other than pharmacological treatment. Therefore, this study aimed to investigate the effects of Pilates exercises on IBS symptoms and severity, frequency of complete spontaneous bowel movements, fatigue, anxiety, depression, and body weight in women with IBS.

Methods

Sixty women with IBS, aged 20-45, completed this study. They were randomly assigned to two equal groups: a study group (n = 30) and a control group (n = 30). The study group received an 8-week Pilates exercise program (2 sessions per week) in addition to dietary advice, while the control group received dietary advice only. Inclusion criteria were women, IBS diagnosed based on Rome IV Diagnostic criteria, constipation-predominant IBS, and moderate to severe IBS. The outcome measures were the IBS severity scoring system (IBS-SSS), the frequency of complete spontaneous bowel movements, the modified fatigue impact scale (MFIS), hospital anxiety and depression (HADS) scale, and body weight (BW).

Results

The study group showed more significant improvements than the control group in total IBS-SSS score (Cohen d = 0.73, p < 0.001), frequency of complete spontaneous bowel movements (Cohen d = 0.50, p < 0.001), total MFIS score (Cohen d = 0.74, p < 0.001), anxiety (Cohen d = 0.56, p < 0.001), and depression (Cohen d = 0.64, p < 0.001). The study group also showed a significant reduction in body weight compared to baseline (p < 0.05). The control group showed significant improvements in all outcomes, except body weight, compared to baseline (p < 0.05).

Conclusion

Pilates exercises, used in addition to dietary advice, may significantly improve IBS symptoms and severity, frequency of complete spontaneous bowel movements, and alleviate fatigue, anxiety, and depression moderately more than dietary advice alone in women with constipation-predominant IBS. Nevertheless, dietary advice alone may also significantly improve these outcomes in this cohort.

Depression and the Aberrant Intestinal Microbiome

Depression is one of the most common mental health disorders affecting adults in the United States. The current treatment is the combination of pharmacotherapy and psychotherapy. Recently, the evidence linking gut microbiome dysregulation to the development of depression has grown. The pathophysiology is currently poorly understood, although leading hypotheses include involvement of the hypothalamic-pituitary-adrenal axis, a bidirectional relationship between the gut microbiome and the central nervous system, and production of signaling molecules by the gut microbiome. Available and emerging treatments of the aberrant microbiome include antidepressants, antibiotics, diet modification, probiotics, and fecal microbiota transplant. This article explores the interconnectivity of gut microbiota and depression and treatments targeted toward the gut, reviews the gastroenterologist's potential role in managing gut dysbiosis in patients with depression, and highlights research topics to be addressed to create evidence-based guidelines.

Casein glycomacropeptide in phenylketonuria: does it bring clinical benefit?

PURPOSE OF REVIEW

Casein glycomacropeptide (CGMP) is a milk-derived bioactive sialyated phosphorylated peptide with distinctive nutritional and nutraceutical properties, produced during the cheese making process. It comprises 20-25% of total protein in whey products. CGMP is low in phenylalanine (Phe) and provides an alternative to Phe-free amino acids as a source of protein equivalent for patients with phenylketonuria (PKU). The amino acid sequence of CGMP is adapted by adding the amino acids histidine, leucine, tyrosine, arginine and tryptophan to enable its suitability in PKU. CGMP has potential antibacterial, antioxidative, prebiotic, remineralizing, digestion /metabolism and immune-modulating properties. The aim of this review is to assess the evidence for the role of CGMP in the management of PKU.

RECENT FINDINGS

In PKU, there is no agreement concerning the amino acid composition of CGMP protein substitutes and consequently the nutritional composition varies between products. Although there is evidence in patients or animal models that CGMP has possible beneficial effects on gut microbiota and bone health, the results are inconclusive. Data on kinetic advantage is limited. Most studies report an increase in blood Phe levels with CGMP. Appropriate adaptations and reduction of dietary Phe intake should be made to compensate for the residual Phe content of CGMP, particularly in children. Data from short term studies indicate improved palatability of CGMP when compared to Phe-free amino acids.

SUMMARY

In PKU, CGMP with supplementary amino acids, offers a safe low Phe nitrogen source. Current scientific evidence is unconvincing about its bioactive advantage in PKU. Further longitudinal research is necessary.

The Gut-Brain Axis and the Microbiome in Anxiety Disorders, Post-Traumatic Stress Disorder and Obsessive-Compulsive Disorder

A large body of research supports the role of stress in several psychiatric disorders in which anxiety is a prominent symptom. Other research has indicated that the gut microbiome-immune system- brain axis is involved in a large number of disorders and that this axis is affected by various stressors. The focus of the current review is on the following stress-related disorders: generalized anxiety disorder, panic disorder, social anxiety disorder, post-traumatic stress disorder and obsessivecompulsive disorder. Descriptions of systems interacting in the gut-brain axis, microbiome-derived molecules and of pro- and prebiotics are given. Preclinical and clinical studies on the relationship of the gut microbiome to the psychiatric disorders mentioned above are reviewed. Many studies support the role of the gut microbiome in the production of symptoms in these disorders and suggest the potential for pro- and prebiotics for their treatment, but there are also contradictory findings and concerns about the limitations of some of the research that has been done. Matters to be considered in future research include longer-term studies with factors such as sex of the subjects, drug use, comorbidity, ethnicity/ race, environmental effects, diet, and exercise taken into account; appropriate compositions of pro- and prebiotics; the translatability of studies on animal models to clinical situations; and the effects on the gut microbiome of drugs currently used to treat these disorders. Despite these challenges, this is a very active area of research that holds promise for more effective, precision treatment of these stressrelated disorders in the future.

Microbes, oxytocin and stress: Converging players regulating eating behavior

Oxytocin is a peptide-hormone extensively studied for its multifaceted biological functions and has recently gained attention for its role in eating behavior, through its action as an anorexigenic neuropeptide. Moreover, the gut microbiota is involved in oxytocinergic signaling through the brain-gut axis, specifically in the regulation of social behavior. The gut microbiota is also implicated in appetite regulation and is postulated to play a role in central regulation of hedonic eating. In this review, we provide an overview on oxytocin and its individual links with the microbiome, the homeostatic and non-homeostatic regulation of eating behavior as well as social behavior and stress.

Role of the gut-microbiota-metabolite-brain axis in the pathogenesis of preterm brain injury

Brain injury, a common complication in preterm infants, includes the destruction of the key structural and functional connections of the brain and causes neurodevelopmental disorders; it has high morbidity and mortality rates. The exact mechanism underlying brain injury in preterm infants is unclear. Intestinal flora plays a vital role in brain development and the maturation of the immune system in infants; however, detailed understanding of the gut microbiota-metabolite-brain axis in preterm infants is lacking. In this review, we summarise the key mechanisms by which the intestinal microbiota contribute to neurodevelopment and brain injury in preterm infants, with special emphasis on the influence of microorganisms and their metabolites on the regulation of neurocognitive development and neurodevelopmental risks related to preterm birth, infection and neonatal necrotising enterocolitis (NEC). This review provides support for the development and application of novel therapeutic strategies, including probiotics, prebiotics, synbiotics, and faecal bacteria transplantation targeting at brain injury in preterm infants.

Depression and lifestyle: Focusing on nutrition, exercise, and their possible relevance to molecular mechanisms

Accumulating evidence has suggested the important role of lifestyle factors in depressive disorder. This paper aimed to introduce and outline recent research on epidemiological and intervention studies on lifestyle-related factors in depressive disorder with a special focus on diet. Evidence on exercise, sleep. and related behaviors is also described. Here, findings from meta-analytic studies are emphasized and related studies by the author's research group are introduced. Dietary factors that increase the risk of the illness include energy overload, skipping breakfast, unhealthy diet styles such as Western diet, inflammation-prone diet, and high consumption of ultraprocessed food (UPF). Nutritional imbalances such as inadequate intake of protein, fish (Ω3 polyunsaturated fatty acids), vitamins (folate and vitamin D), and minerals (iron and zinc) increases the risk of depression. Poor oral hygiene, food allergy, addiction to alcohol, and smoking constitute risk factors. Sedentary lifestyle and increased screen time (e.g. video games and the internet) confer the risk of depression. Insomnia and disturbed sleep-wake rhythm are also involved in the pathogenesis of depression. There is accumulating evidence at the meta-analysis level for interventions to modify these lifestyle habits in the protection and treatment of depressive disorder. Main biological mechanisms of the link between lifestyle factors and depression include monoamine imbalance, inflammation, altered stress response, oxidative stress, and dysfunction of brain-derived neurotrophic factor, although other players such as insulin, leptin, and orexin also play a role. To increase resilience to modern stress and ameliorate depression through modification of lifestyle habits, a list of 30 recommendable interventions is presented.

The emerging role of the endocannabinoidome-gut microbiome axis in eating disorders

Among the sources of chemical signals regulating food intake, energy metabolism and body weight, few have attracted recently as much attention as the expanded endocannabinoid system, or endocannabinoidome (eCBome), and the gut microbiome, the two systems on which this review article is focussed. Therefore, it is legitimate to expect that these two systems also play a major role in the etiopathology of eating disorders (EDs), in particular of anorexia nervosa, bulimia nervosa and binge-eating disorder. The major mechanisms through which, also via interactions with other endogenous signaling systems, the eCBome, with its several lipid mediators and receptors, and the gut microbiome, via its variety of microbial kingdoms, phyla and species, and armamentarium of metabolites, intervene in these disorders, are described here, based on several published studies in either experimental models or patients. Additionally, in view of the emerging multi-faceted cross-talk mechanisms between these two complex systems, we discuss the possibility that the eCBome-gut microbiome axis is also involved in EDs.

The Mediterranean Lifestyle to Contrast Low-Grade Inflammation Behavior in Cancer

A healthy diet and an active lifestyle are both effective ways to prevent, manage, and treat many diseases, including cancer. A healthy, well-balanced diet not only ensures that the body gets the right amount of nutrients to meet its needs, but it also lets the body get substances that protect against and/or prevent certain diseases. It is now clear that obesity is linked to long-term diseases such as heart disease, diabetes, and cancer. The main reasons for people being overweight or obese are having bad eating habits and not moving around enough. Maintaining weight in the normal range may be one of the best things to avoid cancer. It has been scientifically proven that those who perform regular physical activity are less likely to develop cancer than those who lead a sedentary lifestyle. Moving regularly not only helps to maintain a normal body weight, avoiding the effects that favor tumor growth in overweight subjects, but also makes the immune system more resistant by counteracting the growth of tumor cells. Physical activity also helps prevent cardiovascular and metabolic diseases. In this review, it is highlighted that the association between the Mediterranean diet and physical activity triggers biological mechanisms capable of counteracting the low-grade chronic inflammation found in patients with cancer. This assumes that healthy lifestyles associated with cancer therapies can improve the expectations and quality of life of cancer patients.

Impact of Pesticide Residues on the Gut-Microbiota–Blood–Brain Barrier Axis: A Narrative Review

Accumulating evidence indicates that chronic exposure to a low level of pesticides found in diet affects the human gut-microbiota–blood–brain barrier (BBB) axis. This axis describes the physiological and bidirectional connection between the microbiota, the intestinal barrier (IB), and the BBB. Preclinical observations reported a gut microbial alteration induced by pesticides, also known as dysbiosis, a condition associated not only with gastrointestinal disorders but also with diseases affecting other distal organs, such as the BBB. However, the interplay between pesticides, microbiota, the IB, and the BBB is still not fully explored. In this review, we first consider the similarities/differences between these two physiological barriers and the different pathways that link the gut microbiota and the BBB to better understand the dialogue between bacteria and the brain. We then discuss the effects of chronic oral pesticide exposure on the gut-microbiota-BBB axis and raise awareness of the danger of chronic exposure, especially during the perinatal period (pregnant women and offspring).

Gut Microbiota, an Additional Hallmark of Human Aging and Neurodegeneration

Gut microbiota represents a diverse and dynamic population of microorganisms harbouring the gastrointestinal tract, which influences host health and disease. Bacterial colonization of the gastrointestinal tract begins at birth and changes throughout life, with age being one of the conditioning factors for its vitality. Aging is also a primary risk factor for most neurodegenerative diseases. Among them, Alzheimeŕs disease (AD) is probably the one where its association with a state of dysbiosis of the gut microbiota has been most studied. In particular, intestinal microbial-derived metabolites have been associated with β-amyloid formation and brain amyloid deposition, tau phosphorylation, as well as neuroinflammation in AD patients. Moreover, it has been suggested that some oral bacteria increase the risk of developing AD. However, the causal connections among microbiome, amyloid-tau interaction, and neurodegeneration need to be addressed. This paper summarizes the emerging evidence in the literature regarding the link between the oral and gut microbiome and neurodegeneration with a focus on AD. Taxonomic features of bacteria as well as microbial functional alterations associated with AD biomarkers are the main points reviewed. Data from clinical studies as well as the link between microbiome and clinical determinants of AD are particularly emphasized. Further, relationships between gut microbiota and age-dependent epigenetic changes and other neurological disorders are also described. Together, all this evidence suggests that, in some sense, gut microbiota can be seen as an additional hallmark of human aging and neurodegeneration.

Self-reported ongoing adherence to diet is associated with lower depression, fatigue, and disability, in people with multiple sclerosis

Introduction

Increasingly, dietary improvements have been shown to have positive associations with health outcomes in people with multiple sclerosis (pwMS). However, adhering to a MS-specific or high-quality diet may be a challenge. We therefore assessed the level of diet-adherence necessary to improve health outcomes of depression, fatigue, and disability.

Methods

Data from an international population of pwMS followed over 7.5 years (n = 671) were analyzed. Self-reported diet quality via diet habits questionnaire (DHQ), and adherence to six MS-diets [Ashton Embry Best Bet, McDougall, Overcoming MS (OMS), Paleolithic (Paleo), Swank, and Wahls] were queried at two timepoints. Four levels of diet adherence were assessed: non-adherence at either timepoint; ceased at second timepoint; commenced at second timepoint; and ongoing at both timepoints. Associations between adherence to OMS and high-quality diet (DHQ score > median) with depression, fatigue, and disability, were assessed by log-binomial regression models adjusted for confounders.

Results

Forty-two percent of pwMS reported ongoing-adherence to a MS-diet at both timepoints, OMS (33%), Swank (4%), Wahls (1.5%), other (<1%). Of these, only OMS-diet adherence was analyzed for associations due to data availability. Ongoing-adherence to the OMS-diet or a high-quality diet, was associated with lower depression compared to non-adherence [OMS: Risk ratios (RR) = 0.80, p = 0.021; DHQ: RR = 0.78, p = 0.009] and ceased-adherence (OMS: RR = 0.70, p = 0.008; DHQ: RR = 0.70, p = 0.010), respectively. Ongoing-adherence to OMS-diet was associated with lower fatigue (RR = 0.71, p = 0.031) and lower severe disability (RR = 0.43, p = 0.033) compared to ceased-adherence.

Conclusion

Results suggest potential benefits of adherence to the OMS- or a high-quality diet on MS health outcomes, with ongoing-adherence likely best. Diet modification and maintenance may serve as a point of intervention to manage MS symptoms, especially depression, in pwMS.