Understanding the Role of the Gut Microbiome in Brain Development and Its Association With Neurodevelopmental Psychiatric Disorders

The role of the gut microbiome in the associations between lead exposure and child neurodevelopment

Lead is highly toxic to the developing brain. Given its persistence in the environment, new intervention strategies are needed to mitigate the impacts of lead on child neurodevelopment. The gut microbiome, referring to the bacteria and microorganisms residing in the gastrointestinal system, may be a viable target for intervention. This short review summarizes recent evidence linking the gut-brain axis to child developmental outcomes. We explore how lead-induced effects to the gut microbiome could indirectly affect child neurodevelopment, such that disrupting or offsetting this mediating process could buffer the effects of lead on child developmental outcomes. Unexpected findings with respect to child microbiota diversity and child cognitive and behavioral outcomes as well as lead exposure and adult microbiota diversity are discussed. When possible, we draw connections between observed changes to relative bacterial abundance, proposed bacterial functions, and downstream effects to brain development. We also explore how the gut microbiome might modify the toxicity of lead by impeding the uptake of lead across the gastrointestinal tract or through indirect mechanisms in such ways that the gut microbiome does not fit within a mediating pathway. In this case, promoting the buffering capacity of the gut microbiome may reduce the impacts of lead on child neurodevelopment. The goal of this short review is to bring attention to the potential role of the gut microbiome in the associations between lead exposure and child neurodevelopment with an eye towards intervention.

Gut-immune-brain interactions during neurodevelopment: from a brain-centric to a multisystem perspective

BACKGROUND

Neurodevelopmental disorders (NDDs) and epileptic syndromes are complex neurological conditions linked by shared abnormal neurobiological processes. Existing therapies mostly target symptoms, rather than addressing the underlying causes of the disease, leaving a burden of unmet clinical needs.

MAIN BODY

Emerging evidence suggests a significant role for the gut microbiota and associated immune responses in influencing brain development and function, changing the paradigm of a brain-centric origin of NDDs. This review discusses the pivotal interactions within the gut-immune-brain axis, highlighting how microbial dysbiosis and immune signaling contribute to neurological pathologies. We also explore the potential of microbial management and immunomodulation as novel therapeutic avenues, emphasizing the need for a shift towards addressing the root causes of these disorders rather than just their symptoms.

CONCLUSIONS

This integrated perspective offers new insights into the biological underpinnings of NDDs and epilepsy, proposing innovative biomarkers and therapeutic strategies.

Dietary Habits and Their Influence on the Microbiome and Mental Health in Adolescents

Adolescence represents a critical developmental stage where diet, gut microorganisms, and mental health are strongly interconnected. The current literature evidences the bidirectional role between dietary habits and psychological well-being, which is mediated by the gut-brain axis. The purpose of this review is to highlight the importance of dietary habits in adolescence period and the impact of different food choices on microbiota and secondary on mental health. Gut microbiota plays a vital role in the synthesis of neurotransmitters such as serotonin, dopamine, noradrenaline, and metabolites like short-chain fatty acids (SCFAs). The disruption in the composition of microbiota is called dysbiosis, which has been associated with a systemic inflammation state and chronic stress. They contribute to the onset of psychiatric disorders including MDD, anxiety, ADHD, and autism. Diets with a high quantity of sugar and low fiber contribute to alteration of microbiota and poor mental health. Additionally, early-life stress, antibiotic usage, and chronic inflammation may alter bacterial communities, with long-term implications for adolescents mental health. Dietary interventions, including the intake of prebiotics, probiotics, SCFAs, and micronutrients could restore microbial balance and improve psychiatric symptoms. This literature review highlights the critical role of diet and gut microbiota for adolescent mental health and emphasizes the need for integrative strategies to promote psychological resilience through microbiome regulation.

Abnormal microbiota due to prenatal antibiotic as a possible risk factor for Attention-Deficit / Hyperactivity Disorder (ADHD)

One of the major issues modern medicine faces is the increasing use of antibiotics in reaction to the increased incidence of infectious agents. The current trend of antibiotic overuse contributes to microbial dysbiosis. Recent studies have hypothesized that antibiotic exposure during pregnancy, which alters the composition of the microbiome, might increase the likelihood of attention deficit hyperactivity disorder (ADHD). In addition to the ongoing discussion about the potential links between antibiotic usage, microbiome dysbiosis, and ADHD, there is a rising interest in integrating AI and ML into healthcare practices. Diagnosis, treatment plans, and prognoses are all enhanced by these technological advancements. Remote monitors or telemedicine monitoring are among the management techniques described in this chapter for effectively managing illnesses. Also discussed are ways to halt the progression of diseases by preventative measures that use biosensor technology and dietary approaches. Personalized treatment programs, disease progression stages, and prognosis evaluations are all made possible with the use of artificial intelligence and machine learning. By using these technologies to provide individualized therapy, healthcare practitioners may get a better understanding of ADHD and perhaps improve patient outcomes.

Microbiome Gut-Brain-Axis: Impact on Brain Development and Mental Health

The current discovery that the gut microbiome, which contains roughly 100 trillion microbes, affects health and disease has catalyzed a boom in multidisciplinary research efforts focused on understanding this relationship. Also, it is commonly demonstrated that the gut and the CNS are closely related in a bidirectional pathway. A balanced gut microbiome is essential for regular brain activities and emotional responses. On the other hand, the CNS regulates the majority of GI physiology. Any disruption in this bidirectional pathway led to a progression of health problems in both directions, neurological and gastrointestinal diseases. In this review, we hope to shed light on the complicated connections of the microbiome-gut-brain axis and the critical roles of gut microbiome in the early development of the brain in order to get a deeper knowledge of microbiome-mediated pathological conditions and management options through rebalancing of gut microbiome.

Identification of diagnostic and therapeutic biomarkers for attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric condition among children and adolescents, often associated with a high risk of psychiatric comorbidities. Currently, ADHD diagnosis relies exclusively on clinical presentation and patient history, underscoring the need for clinically relevant, reliable, and objective biomarkers. Such biomarkers may enable earlier diagnosis and lead to improved treatment outcomes. Our research team has focused on identifying potential biomarkers for ADHD by investigating its possible pathomechanisms, with consideration of the aforementioned criteria. Given the significant sex-related differences in ADHD prevalence (male predominance) and the age-related variability in its symptomatology, we explored the role of neuroendocrine systems in ADHD. Specifically, we examined the epigenetic regulation mechanism involved in ADHD pathogenesis and developed a diagnostic model based on peripheral microRNA. Additionally, we investigated the role of microbiota dysbiosis in the pathophysiology of ADHD and provided novel insights into its management. This paper presents a summary of our findings on potential biomarkers for ADHD. By analyzing blood, salivary, and fecal samples, we identified several promising biomarkers that may serve as objective parameters for improving the diagnostic accuracy for ADHD. Further research involving larger cohort studies is required to confirm the reliability of these biomarkers.

Ghrelin in Depression: A Promising Therapeutic Target

Depression is a widespread disease affecting over 300 million individuals of various ethnicities and socioeconomic backgrounds globally. It frequently strikes early in life and becomes a chronic or recurring lifelong illness. Out of the various hypotheses for the pathophysiology of depression, the gut-brain axis and stress hypothesis are the ones that need to be researched, as psychological stress impairs one or more pathways of the brain-gut axis and is likely to cause brain-gut axis dysfunction and depression. A dysfunctional reciprocal gut-brain relationship may contribute to many diseases, including inflammatory disorders, abnormal stress responses, impaired behavior, and metabolic changes. The hormone ghrelin is a topic of interest concerning the gut-brain axis as it interacts with the gut-brain axis indirectly via the central nervous system or via crossing the blood-brain barrier. Ghrelin release is also affected by the gut microbes, which has also been discussed in the review. This review elaborates on Ghrelin's role in depression and its effect on various aspects like neurogenesis, HPA axis, and neuroinflammation. Furthermore, this review focuses on ghrelin as a potential target for alleviation of depressive symptoms.

Nutritional Interventions in Amyotrophic Lateral Sclerosis: From Ketogenic Diet and Neuroprotective Nutrients to the Microbiota-Gut-Brain Axis Regulation

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disease with significant challenges in diagnosis and treatment. Recent research has highlighted the complex nature of ALS, encompassing behavioral impairments in addition to its neurological manifestations. While several medications have been approved to slow disease progression, ongoing research is focused on identifying new therapeutic targets. The current review focuses on emerging therapeutic strategies and personalized approaches aimed at improving patient outcomes. Recent advancements highlight the importance of targeting additional pathways such as mitochondrial dysfunction and neuroinflammation to develop more effective treatments. Personalized medicine, including genetic testing and biomarkers, is proving valuable in stratifying patients and tailoring treatment options. Complementary therapies, such as nutritional interventions like the ketogenic diet and microbiome modulation, also show promise. This review emphasizes the need for a multidisciplinary approach that integrates early diagnosis, targeted treatments, and supportive care to address the multisystemic nature of ALS and improve the quality of life for patients.

Nutritional Strategies in Major Depression Disorder: From Ketogenic Diet to Modulation of the Microbiota-Gut-Brain Axis

Major depressive disorder (MDD) is a leading cause of disability worldwide. While traditional pharmacological treatments are effective for many cases, a significant proportion of patients do not achieve full remission or experience side effects. Nutritional interventions hold promise as an alternative or adjunctive approach, especially for treatment-resistant depression. This review examines the potential role of nutrition in managing MDD through addressing biological deficits and modulating pathways relevant to its pathophysiology. Specifically, it explores the ketogenic diet and gut microbiome modulation through various methods, including probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation. Numerous studies link dietary inadequacies to increased MDD risk and deficiencies in nutrients like omega-3 s, vitamins D and B, magnesium, and zinc. These deficiencies impact neurotransmitters, inflammation, and other biological factors in MDD. The gut-brain axis also regulates mood, stress response, and immunity, and disruptions are implicated in MDD. While medications aid acute symptoms, nutritional strategies may improve long-term outcomes by preventing relapse and promoting sustained remission. This comprehensive review aims to provide insights into nutrition's multifaceted relationship with MDD and its potential for developing more effective integrated treatment approaches.

Sustaining Brain Youth by Neural Stem Cells: Physiological and Therapeutic Perspectives

In the last two decades, stem cells (SCs) have attracted considerable interest for their research value and therapeutic potential in many fields, namely in neuroscience. On the other hand, the discovery of adult neurogenesis, the process by which new neurons are generated in the adult brain, challenged the traditional view that the brain is a static structure after development. The recent findings showing that adult neurogenesis has a significant role in brain plasticity, learning and memory, and emotional behavior, together with the fact that it is strongly dependent on several external and internal factors, have sparked more interest in this area. The mechanisms of adult neural stem cell (NSC) regulation, the physiological role of NSC-mediated neuroplasticity throughout life, and the most recent NSC-based therapeutic applications will be concisely reviewed. Noteworthy, due to their multipotency, self-renewal potential, and ability to secrete growth and immunomodulatory factors, NSCs have been mainly suggested for (1) transplantation, (2) neurotoxicology tests, and (3) drug screening approaches. The clinical trials of NSC-based therapy for different neurologic conditions are, nonetheless, mostly in the early phases and have not yet demonstrated conclusive efficacy or safety. Here, we provide an outlook of the major challenges and limitations, as well as some promising directions that could help to move toward stem cell widespread use in the treatment and prevention of several neurological disorders.

The Neonatal Microbiome: Implications for Amyotrophic Lateral Sclerosis and Other Neurodegenerations

Most brain development occurs in the "first 1000 days", a critical period from conception to a child's second birthday. Critical brain processes that occur during this time include synaptogenesis, myelination, neural pruning, and the formation of functioning neuronal circuits. Perturbations during the first 1000 days likely contribute to later-life neurodegenerative disease, including sporadic amyotrophic lateral sclerosis (ALS). Neurodevelopment is determined by many events, including the maturation and colonization of the infant microbiome and its metabolites, specifically neurotransmitters, immune modulators, vitamins, and short-chain fatty acids. Successful microbiome maturation and gut-brain axis function depend on maternal factors (stress and exposure to toxins during pregnancy), mode of delivery, quality of the postnatal environment, diet after weaning from breast milk, and nutritional deficiencies. While the neonatal microbiome is highly plastic, it remains prone to dysbiosis which, once established, may persist into adulthood, thereby inducing the development of chronic inflammation and abnormal excitatory/inhibitory balance, resulting in neural excitation. Both are recognized as key pathophysiological processes in the development of ALS.

Modulation of the Neuro-Cancer Connection by Metabolites of Gut Microbiota

The gut-brain-cancer axis represents a novel and intricate connection between the gut microbiota, neurobiology, and cancer progression. Recent advances have accentuated the significant role of gut microbiota metabolites in modulating systemic processes that influence both brain health and tumorigenesis. This paper explores the emerging concept of metabolite-mediated modulation within the gut-brain-cancer connection, focusing on key metabolites such as short-chain fatty acids (SCFAs), tryptophan derivatives, secondary bile acids, and lipopolysaccharides (LPS). While the gut microbiota's impact on immune regulation, neuroinflammation, and tumor development is well established, gaps remain in grasping how specific metabolites contribute to neuro-cancer interactions. We discuss novel metabolites with potential implications for neurobiology and cancer, such as indoles and polyamines, which have yet to be extensively studied. Furthermore, we review preclinical and clinical evidence linking gut dysbiosis, altered metabolite profiles, and brain tumors, showcasing limitations and research gaps, particularly in human longitudinal studies. Case studies investigating microbiota-based interventions, including dietary changes, fecal microbiota transplantation, and probiotics, demonstrate promise but also indicate hurdles in translating these findings to clinical cancer therapies. This paper concludes with a call for standardized multi-omics approaches and bi-directional research frameworks integrating microbiome, neuroscience, and oncology to develop personalized therapeutic strategies for neuro-cancer patients.

Impact of antidepressants on the composition of the gut microbiome: A systematic review and meta-analysis of in vivo studies

BACKGROUND

There is a growing body of evidence suggesting that antidepressant drugs (ADs) alter the gut microbiome of persons with depressive disorders. Herein, we aim to investigate the gut microbial profile of AD-treated animal models of depression (MoD) and persons with major depressive disorder (MDD).

METHODS

We conducted a systematic review and meta-analysis investigating the gut microbiome community-level diversity and relative abundance of microbial taxa in AD-treated animal MoD and persons with MDD.

RESULTS

24 human studies (898 participants) and 48 animal studies (849 subjects) were identified. Nonsignificant differences in gut microbial richness were observed between AD-treated and nonmedicated animals and humans. Beta diversity analysis in animals shows that AD intake is linked to a distinct gut microbial profile, a result not observed in humans. Consistent depletion of the genera Faecalibacterium and Parasutterella, along with enrichment of Bifidobacterium, was observed in AD-treated persons with MDD. In AD-treated animals, AD intake was associated with depletion of Flavobacterium and Adlercreutzia, and enrichment of Parabacteroides.

LIMITATIONS

The studies in our review were heterogeneous in their participant population, dietary intake, type of ADs used, length and dosing of AD treatment, and frequency and time of fecal sample collection.

CONCLUSION

ADs are associated with some changes to the gut microbiome. Future studies should evaluate the gut microbiome profiles between depressive disorder diagnoses that may reveal potential differences and predictors of AD response, as well as new combinatorial therapeutics with agents (e.g., specific-strain probiotic adjunctive treatment) that can ameliorate micro-composition gut dysbiosis.

Neuroglia and the microbiota-gut-brain axis

Glial cells are key players in the regulation of nervous system functioning in both the central and enteric nervous systems. Glial cells are dynamic and respond to environmental cues to modulate their activity. Increasing evidence suggests that these signals include those originating from the gut microbiota, the community of microorganisms, including bacteria, viruses, archaea, and protozoa, that inhabit the gut. The gut microbiota and the brain communicate in a bidirectional manner across multiple signaling pathways and interfaces that together comprise the microbiota-gut-brain axis. Here, we detail the role of glial cells, including astrocytes, microglia, and oligodendrocytes in the central nervous system, and glial cells in the enteric nervous system along this gut-brain axis. We review what is known regarding the modulation of glia by microbial signals, in particular by microbial metabolites which signal to the brain through systemic circulation and via the vagus nerve. In addition, we highlight what is yet to be discovered regarding the role of other gut microbiota signaling pathways in glial cell modulation and the challenges of research in this area.

Gut microbiome-gut brain axis-depression: interconnection

OBJECTIVES

The relationship between the gut microbiome and mental health, particularly depression, has gained significant attention. This review explores the connection between microbial metabolites, dysbiosis, and depression. The gut microbiome, comprising diverse microorganisms, maintains physiological balance and influences health through the gut-brain axis, a communication pathway between the gut and the central nervous system.

METHODS

Dysbiosis, an imbalance in the gut microbiome, disrupts this axis and worsens depressive symptoms. Factors like diet, antibiotics, and lifestyle can cause this imbalance, leading to changes in microbial composition, metabolism, and immune responses. This imbalance can induce inflammation, disrupt neurotransmitter regulation, and affect hormonal and epigenetic processes, all linked to depression.

RESULTS

Microbial metabolites, such as short-chain fatty acids and neurotransmitters, are key to gut-brain communication, influencing immune regulation and mood. The altered production of these metabolites is associated with depression. While progress has been made in understanding the gut-brain axis, more research is needed to clarify causative relationships and develop new treatments. The emerging field of psychobiotics and microbiome-targeted therapies shows promise for innovative depression treatments by harnessing the gut microbiome's potential.

CONCLUSIONS

Epigenetic mechanisms, including DNA methylation and histone modifications, are crucial in how the gut microbiota impacts mental health. Understanding these mechanisms offers new prospects for preventing and treating depression through the gut-brain axis.

Cross-talk between adipose tissue and microbiota-gut-brain-axis in brain development and neurological disorder

The gut microbiota is an important factor responsible for the physiological processes as well as pathogenesis of host. The communication between central nervous system (CNS) and microbiota occurs by different pathways i.e., chemical, neural, immune, and endocrine. Alteration in gut microbiota i.e., gut dysbiosis causes alteration in the bidirectional communication between CNS and gut microbiota and linked to the pathogenesis of neurological and neurodevelopmental disorder. Therefore, now-a-days microbiota-gut-brain-axis (MGBA) has emerged as therapeutic target for the treatment of metabolic disorder. But, experimental data available on MGBA from basic research has limited application in clinical study. In present study we first summarized molecular mechanism of microbiota interaction with brain physiology and pathogenesis via collecting data from different sources i.e., PubMed, Scopus, Web of Science. Furthermore, evidence shows that adipose tissue (AT) is active during metabolic activities and may also interact with MGBA. Hence, in present study we have focused on the relationship among MGBA, brown adipose tissue, and white adipose tissue. Along with this, we have also studied functional specificity of AT, and understanding heterogeneity among MGBA and different types of AT. Therefore, molecular interaction among them may provide therapeutic target for the treatment of neurological disorder.

Targeting inflammation and gut microbiota with antibacterial therapy: Implications for central nervous system health

The complex symbiotic relationship between inflammation, the gut microbiota, and the central nervous system (CNS) has become a pivotal focus of contemporary biomedical research. Inflammation, as a physiological defense mechanism, plays a dual role as both a protective and pathological factor, and is intricately associated with gut microbiota homeostasis, often termed the "second brain." The gutbrain axis (GBA) exemplifies this multifaceted interaction, where gut health exerts significantly regulatory effects on CNS functions. Antibacterial therapies represent both promising and challenging strategies for modulating inflammation and gut microbiota composition to confer CNS benefits. However, while such therapies may exert positive modulatory effects on the gut microbiota, they also carry the potential to disrupt microbial equilibrium, potentially exacerbating neurological dysfunction. Recent advances have provided critical insights into the therapeutic implications of antibacterial interventions; nevertheless, the application of these therapies in the context of CNS health warrants a judicious and evidence-based approach. As research progresses, deeper investigation into the microbial-neural interface is essential to fully realize the potential of therapies targeting inflammation and the gut microbiota for CNS health. Future efforts should focus on refining antibacterial interventions to modulate the gut microbiota while minimizing disruption to microbial balance, thereby reducing risks and enhancing efficacy in CNS-related conditions. In conclusion, despite challenges, a more comprehensive understanding of the GBA, along with precise modulation through targeted antibacterial therapies, offers significant promise for advancing CNS disorder treatment. Continued research in this area will lead to innovative interventions and improved patient outcomes.

Maternal gut-microbiota impacts the influence of intrauterine environmental stressors on the modulation of human cognitive development and behavior

This review examines the longstanding debate of nature and intrauterine environmental challenges that shapes human development and behavior, with a special focus on the influence of maternal prenatal gut microbes. Recent research has revealed the critical role of the gut microbiome in human neurodevelopment, and evidence suggest that maternal microbiota can impact fetal gene and microenvironment composition, as well as immunophysiology and neurochemical responses. Furthermore, intrauterine neuroepigenetic regulation may be influenced by maternal microbiota, capable of having long-lasting effects on offspring behavior and cognition. By examining the complex relationship between maternal prenatal gut microbes and human development, this review highlights the importance of early-life environmental factors in shaping neurodevelopment and cognition.

Impact of Probiotics and Prebiotics on Gut Microbiome and Hormonal Regulation

The gut microbiome plays a crucial role in human health by influencing various physiological functions through complex interactions with the endocrine system. These interactions involve the production of metabolites, signaling molecules, and direct communication with endocrine cells, which modulate hormone secretion and activity. As a result, the microbiome can exert neuroendocrine effects and contribute to metabolic regulation, adiposity, and appetite control. Additionally, the gut microbiome influences reproductive health by altering levels of sex hormones such as estrogen and testosterone, potentially contributing to conditions like polycystic ovary syndrome (PCOS) and hypogonadism. Given these roles, targeting the gut microbiome offers researchers and clinicians novel opportunities to improve overall health and well-being. Probiotics, such as Lactobacillus and Bifidobacterium, are live beneficial microbes that help maintain gut health by balancing the microbiota. Prebiotics, non-digestible fibers, nourish these beneficial bacteria, promoting their growth and activity. When combined, probiotics and prebiotics form synbiotics, which work synergistically to enhance the gut microbiota balance and improve metabolic, immune, and hormonal health. This integrated approach shows promising potential for managing conditions related to hormonal imbalances, though further research is needed to fully understand their specific mechanisms and therapeutic potential.

Relationships between Gut Microbiota and Autism Spectrum Disorders: Development and Treatment

Many studies have demonstrated the impact of intestinal microbiota on normal brain development. Moreover, the gut microbiota (GM) is impacted by multiple endogenous and environmental factors that may promote gut dysbiosis (GD). An increasing number of studies are investigating the possible role of the GD in the development of neurological and behavioral disorders. For autism spectrum disorders (ASD), specific intestinal bacterial signatures have been identified, knowing that gastrointestinal symptoms are frequently found in ASD. In this review, the peri and post-natal factors modulating the GM are described and the specific gut bacterial signature of ASD children is detailed. Through bidirectional communication between the GM and the brain, several mechanisms are involved in the development of ASD, such as cytokine-mediated neuroinflammation and decreased production of neuroprotective factors such as short-chain fatty acids by the GM. Imbalance of certain neurotransmitters such as serotonin or gamma-aminobutyric acid could also play a role in these gut-brain interactions. Some studies show that this GD in ASD is partly reversible by treatment with pre- and probiotics, or fecal microbiota transplantation with promising results. However, certain limitations have been raised, in particular concerning the short duration of treatment, the small sample sizes and the diversity of protocols. The development of standardized therapeutics acting on GD in large cohort could rescue the gastrointestinal symptoms and behavioral impairments, as well as patient management.

A Comprehensive Review on Dietary Polysaccharides as Prebiotics, Synbiotics, and Postbiotics in Infant Formula and Their Influences on Gut Microbiota

Human milk contains an abundance of nutrients which benefit the development and growth of infants. However, infant formula has to be used when breastfeeding is not possible. The large differences between human milk and infant formula in prebiotics lead to the suboptimal intestinal health of infant formula-fed infants. This functional deficit of infant formula may be overcome through other dietary polysaccharides that have been characterized. The aim of this review was to summarize the potential applications of dietary polysaccharides as prebiotics, synbiotics, and postbiotics in infant formula to better mimic the functionality of human milk prebiotics for infant gut health. Previous studies have demonstrated the influences of dietary polysaccharides on gut microbiota, SCFA production, and immune system development. Compared to prebiotics, synbiotics and postbiotics showed better application potential in shaping the gut microbiota, the prevention of pathogen infections, and the development of the immune system. Moreover, the safety issues for biotics still require more clinical trials with a large-scale population and long time duration, and the generally accepted regulations are important to regulate related products. Pectin polysaccharides has similar impacts to human milk oligosaccharides on gut microbiota and the repairing of a damaged gut barrier, with similar functions also being observed for inulin and β-glucan. Prebiotics as an encapsulation material combined with probiotics and postbiotics showed better potential applications compared to traditional material in infant formula.

Enriching the Mediterranean diet could nourish the brain more effectively

The increasing prevalence of neurodegenerative disorders represents a challenge to the global health of all nations and populations, particularly with increasing longevity. Urgent prevention strategies are therefore needed, and one opportunity may be to explore the relationship between dietary patterns and brain health which has emerged as a promising strategy. Numerous studies indicate that dietary choices have a significant impact on cognitive function, memory and the risks of neurological disorders, recognizing the dynamic role of diet in maintaining cognitive abilities. One of the most studied dietary styles, the Mediterranean diet, characterized by healthy, plant-based foods fats and moderate consumption of animal products, has demonstrated its neuroprotective potential. Rich in antioxidants, vitamins and polyphenols, this diet shows consistent associations with cardiovascular health and cognitive function. Some less talked about foods, such as seaweed, blackcurrants, Lion's Mane mushroom and chia seeds, are emerging as potential brain health boosters. These and other new foods could enrich the Western diet making it capable of effectively preventing neurological disorders. Despite promising scientific data, difficulties persist in understanding the complex relationship between nutrition and brain health. Individual variability, long-term dietary adherence, comorbidities, and the need for rigorous clinical evidence pose obstacles. In this review, we would like to focus our attention on the future of brain-diets, which should involve accessible, personalized and evidence-based interventions, providing hope against the challenges posed by neurodegenerative diseases. In fact, as research progresses, more and more attention are being placed to brain health, promising a harmonious and resilient cognitive landscape for individuals and society.

Roles of the gut microbiota in human neurodevelopment and adult brain disorders

Growing evidence demonstrates the connection between gut microbiota, neurodevelopment, and adult brain function. Microbial colonization occurs before the maturation of neural systems and its association with brain development. The early microbiome interactions with the gut-brain axis evolved to stimulate cognitive activities. Gut dysbiosis can lead to impaired brain development, growth, and function. Docosahexaenoic acid (DHA) is critically required for brain structure and function, modulates gut microbiota, and impacts brain activity. This review explores how gut microbiota influences early brain development and adult functions, encompassing the modulation of neurotransmitter activity, neuroinflammation, and blood-brain barrier integrity. In addition, it highlights processes of how the gut microbiome affects fetal neurodevelopment and discusses adult brain disorders.

Gut dysbiosis mediates the association between antibiotic exposure and chronic disease

Antibiotics are safe, effective drugs and continue to save millions of lives and prevent long-term illness worldwide. A large body of epidemiological, interventional and experimental evidence shows that exposure to antibiotics has long-term negative effects on human health. We reviewed the literature data on the links between antibiotic exposure, gut dysbiosis, and chronic disease (notably with regard to the "developmental origins of health and disease" ("DOHaD") approach). Molecular biology studies show that the systemic administration of antibiotic to infants has a rapid onset but also often a long-lasting impact on the microbial composition of the gut. Along with other environmental factors (e.g., an unhealthy "Western" diet and sedentary behavior), antibiotics induce gut dysbiosis, which can be defined as the disruption of a previously stable, functionally complete microbiota. Gut dysbiosis many harmful long-term effects on health. Associations between early-life exposure to antibiotics have been reported for chronic diseases, including inflammatory bowel disease, celiac disease, some cancers, metabolic diseases (obesity and type 2 diabetes), allergic diseases, autoimmune disorders, atherosclerosis, arthritis, and neurodevelopmental, neurodegenerative and other neurological diseases. In mechanistic terms, gut dysbiosis influences chronic disease through direct effects on mucosal immune and inflammatory pathways, plus a wide array of direct or indirect effects of short-chain fatty acids, the enteric nervous system, peristaltic motility, the production of hormones and neurotransmitters, and the loss of intestinal barrier integrity (notably with leakage of the pro-inflammatory endotoxin lipopolysaccharide into the circulation). To mitigate dysbiosis, the administration of probiotics in patients with chronic disease is often (but not always) associated with positive effects on clinical markers (e.g., disease scores) and biomarkers of inflammation and immune activation. Meta-analyses are complicated by differences in probiotic composition, dose level, and treatment duration, and large, randomized, controlled clinical trials are lacking in many disease areas. In view of the critical importance of deciding whether or not to prescribe antibiotics (especially to children), we suggest that the DOHaD concept can be logically extended to "gastrointestinal origins of health and disease" ("GOHaD") or even "microbiotic origins of health and disease" ("MOHaD").

Home-ics: how experiences of the home impact biology and child neurodevelopmental outcomes

Studies on the -omics of child neurodevelopmental outcomes, e.g. genome, epigenome, microbiome, metabolome, and brain connectome aim to enable data-driven precision health to improve these outcomes, or deliver the right intervention, to the right child, at the right time. However, evidence suggests that neurodevelopmental outcomes are shaped by modifiable socioenvironmental factors. Everyday exposures including family and neighbourhood-level socioeconomic status, housing conditions, and interactions with those living in the home, are strongly associated with child health and have been suggested to alter -omics. Our aim was to review and understand the biological pathways by which home factors contribute to child neurodevelopment outcomes. We review studies suggestive of the home factors contributing to neurodevelopmental outcomes that encompass the hypothalamic-pituitary-adrenal axis, the brain, the gut-brain-axis, and the immune system. We thus conceptualize home-ics as the study of how the multi-faceted living environment can impact neurodevelopmental outcomes through biology and highlight the importance of targeting the modifiable aspects of a child's home to optimize outcomes. We encourage clinicians and health care providers to routinely assess home factors in patient encounters, and counsel families on modifiable aspects of the home. We conclude by discussing clinical and policy implications and future research directions of home-ics. IMPACT: Home-ics can be conceptualized as the study of how home factors may shape child neurodevelopmental outcomes through altering biology. Targeting modifiable aspects of a child's home environment (e.g. parenting style, early intervention, enriched environment) may lead to improved neurodevelopmental outcomes. Clinicians should routinely assess home factors and counsel families on modifiable aspects of the home.

Biopsychosocial pathways model of early childhood appetite self-regulation: Temperament as a key to modulation of interactions among systems

The widespread discrimination against individuals with obesity often stems from a simplistic perception of obesity as a mere consequence of personal choices of overeating and insufficient physical activity. This reductionist perception fails to acknowledge the complexity of the epidemic of obesity, which extends beyond diet and exercise decisions. The concept of appetite self-regulation (ASR) has been explored as a crucial element in identifying obesogenic behavioral approaches to food. Although an extensive understanding of ASR in children is essential as an early precursor and modifiable factor influencing obesity, the prevailing view of self-regulation of eating solely as a matter of cognitive and behavioral processing tends to overlook interacting systems of influences. This narrow approach attributes obesity to the lack of voluntary self-control in food consumption while neglecting to account for the biological, psychological, and social influences implicated in the developmental processes of ASR, which may further contribute to the stigmatization of obesity. The current critical analysis provides a comprehensive developmental framework that could guide future studies with testable hypotheses, outlining pathways of interactions among biopsychosocial systems, all of which contribute to the development of ASR in early childhood. Adopting developmental perspectives allows a holistic approach to investigating ASR, which accounts for intricate interactions between biological (B), psychological (P), and social (S) factors influential in the early manifestation of ASR.

Exploring the Frontier: The Human Microbiome's Role in Rare Childhood Neurological Diseases and Epilepsy

Emerging research into the human microbiome, an intricate ecosystem of microorganisms residing in and on our bodies, reveals that it plays a pivotal role in maintaining our health, highlighting the potential for microbiome-based interventions to prevent, diagnose, treat, and manage a myriad of diseases. The objective of this review is to highlight the importance of microbiome studies in enhancing our understanding of rare genetic epilepsy and related neurological disorders. Studies suggest that the gut microbiome, acting through the gut-brain axis, impacts the development and severity of epileptic conditions in children. Disruptions in microbial composition can affect neurotransmitter systems, inflammatory responses, and immune regulation, which are all critical factors in the pathogenesis of epilepsy. This growing body of evidence points to the potential of microbiome-targeted therapies, such as probiotics or dietary modifications, as innovative approaches to managing epilepsy. By harnessing the power of the microbiome, we stand to develop more effective and personalized treatment strategies for children affected by this disease and other rare neurological diseases.

From microbes to mind: germ-free models in neuropsychiatric research

The gut-microbiota-brain axis refers to the bidirectional communication system between the gut, its microbial community, and the brain. This interaction involves a complex interplay of neural pathways, chemical transmitters, and immunological mechanisms. Germ-free animal models have been extensively employed to investigate gut-microbiota-brain interactions, significantly contributing to our current understanding of the role of intestinal microbes in brain function. However, despite the many benefits, this absence of microbiota is not futile. Germ-free animals present physiological and neurodevelopmental alterations that can persist even after reconstitution with normal microbiota. Therefore, the main goal of this minireview is to discuss how some of the inherent limitations of this model can interfere with the conclusion obtained when using these animals to study the complex nature of neuropsychiatric disorders. Furthermore, we examine the inclusion and use of antibiotic-based treatments as an alternative in the research of gut-brain interactions.

The Association of the Oral Microbiota with Cognitive Functioning in Adolescence

Background: A growing body of research supports the role of the microbial communities residing in the digestive system in the host's cognitive functioning. Most of these studies have been focused on the gut microbiome and its association with clinical phenotypes in middle-aged and older adults. There is an insufficiency of population-based research exploring the association of normative cognitive functioning with the microbiome particularly with the oral microbiota. Methods: In this study, using metagenomics and metabolomics, we characterized the salivary microbiome diversity in a sample of 51 males of Hispanic and African American origin aged 12-18 years and explored the associations between the microbiome and the youths' cognitive performance captured with the Kaufman Assessment Battery for Children II (KABC-II). Results: Several bacterial species of the oral microbiota and related metabolic pathways were associated with cognitive function. In particular, we found negative associations between indicators of general intelligence and the relative abundance of Bacteroidetes and Lachnospiraceae and positive associations with Bifidobacteriaceae and Prevotella histicola sp. Among metabolic pathways, the super pathways related to bacterial cell division and GABA metabolism were linked to cognitive function. Conclusions: The results of our work are consistent with the literature reporting on the association between microbiota and cognitive function and support further population work to elucidate the potential for a healthy oral microbiome to improve cognitive health.

Systems Biology of Human Microbiome for the Prediction of Personal Glycaemic Response

The human gut microbiota is increasingly recognized as a pivotal factor in diabetes management, playing a significant role in the body's response to treatment. However, it is important to understand that long-term usage of medicines like metformin and other diabetic treatments can result in problems, gastrointestinal discomfort, and dysbiosis of the gut flora. Advanced sequencing technologies have improved our understanding of the gut microbiome's role in diabetes, uncovering complex interactions between microbial composition and metabolic health. We explore how the gut microbiota affects glucose metabolism and insulin sensitivity by examining a variety of -omics data, including genomics, transcriptomics, epigenomics, proteomics, metabolomics, and metagenomics. Machine learning algorithms and genome-scale modeling are now being applied to find microbiological biomarkers associated with diabetes risk, predicted disease progression, and guide customized therapy. This study holds promise for specialized diabetic therapy. Despite significant advances, some concerns remain unanswered, including understanding the complex relationship between diabetes etiology and gut microbiota, as well as developing user-friendly technological innovations. This mini-review explores the relationship between multiomics, precision medicine, and machine learning to improve our understanding of the gut microbiome's function in diabetes. In the era of precision medicine, the ultimate goal is to improve patient outcomes through personalized treatments.

Prenatal Nutritional Factors and Neurodevelopmental Disorders: A Narrative Review

According to the DSM-5, neurodevelopmental disorders represent a group of heterogeneous conditions, with onset during the developmental period, characterized by an alteration of communication and social skills, learning, adaptive behavior, executive functions, and psychomotor skills. These deficits determine an impairment of personal, social, scholastic, or occupational functioning. Neurodevelopmental disorders are characterized by an increased incidence and a multifactorial etiology, including genetic and environmental components. Data largely explain the role of genetic and environmental factors, also through epigenetic modifications such as DNA methylation and miRNA. Despite genetic factors, nutritional factors also play a significant role in the pathophysiology of these disorders, both in the prenatal and postnatal period, underscoring that the control of modifiable factors could decrease the incidence of neurodevelopmental disorders. The preventive role of nutrition is widely studied as regards many chronic diseases, such as diabetes, hypertension, and cancer, but actually we also know the effects of nutrition on embryonic brain development and the influence of prenatal and preconceptional nutrition in predisposition to various pathologies. These factors are not limited only to a correct caloric intake and a good BMI, but rather to an adequate and balanced intake of macro and micronutrients, the type of diet, and other elements such as exposure to heavy metals. This review represents an analysis of the literature as regards the physiopathological mechanisms by which food influences our state of health, especially in the age of development (from birth to adolescence), through prenatal and preconceptional changes, underlying how controlling these nutritional factors should improve mothers' nutritional state to significantly reduce the risk of neurodevelopmental disorders in offspring. We searched key words such as "maternal nutrition and neurodevelopmental disorders" on Pubmed and Google Scholar, selecting the main reviews and excluding individual cases. Therefore, nutrigenetics and nutrigenomics teach us the importance of personalized nutrition for good health. So future perspectives may include well-established reference values in order to determine the correct nutritional intake of mothers through food and integration.

The brain-gut axis: communication mechanisms and the role of the microbiome as a neuroprotective factor in the development of neurodegenerative diseases: A literature overview

The study of the brain-gut axis and its impact on cognitive function and in the development of neurodegenerative diseases is a very timely topic of interest to researchers. This review summarizes information on the basic mechanisms of gut-brain communication. We then discuss the roles of the gut microbiome as a neuroprotective factor in neurodegeneration. The gut microbiota is extremely important in maintaining the body's homeostasis, shaping the human immune system and the proper functioning of the brain. The intestinal microflora affects the processes of neuroplasticity, synaptogenesis, and neuronal regeneration. This review aims to explain changes in the composition of the bacterial population of the intestinal microflora among patients with Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Abnormalities in gut microflora composition are also noted in stress, depression, or autism spectrum development. New observations on psychobiotic supplementation in alleviating the symptoms of neurodegenerative diseases are also presented.

Dietary interventions to improve metabolic health in schizophrenia: A systematic literature review of systematic reviews

AIM

This review of systematic reviews synthesised evidence on the impact of dietary interventions on anthropometric and biochemical measures associated with schizophrenia and metabolic syndrome. Secondly, an aim to identify intervention elements associated with greater dietary adherence and behaviour change.

METHODS

Five databases were searched from 2000-March 2023. Eligible reviews included adults, majority diagnosed with schizophrenia, dietary intervention components and at least one anthropometric or biochemical outcome related to metabolic syndrome. Two independent reviewers performed article selection, data extraction, and quality assessment.

RESULTS

Seven systematic reviews, consisting of 79 unique primary papers were included. No reviews exclusively examined dietary interventions. Nutrition education and counselling administered alongside physical activity were common. All reviews favoured intervention over the control to reduce body weight, body mass index, and waist circumference. Glycaemic control, blood pressure and triglycerides were not routinely reported with mixed effects following interventions. There was insufficient data to examine any trends for dropout rates, dietary adherence, and behaviour change. There was both low (n = 3/7) and high (n = 4/7) risk of bias and degree of study overlap was very high (16.4 %). The level of evidence was rated as suggestive (n = 2/7), weak (n = 2/7), non-significant (n = 1/7) and ungraded (n = 2/7).

CONCLUSION

Dietary interventions administered alongside lifestyle therapies can reduce anthropometric measurements for consumers living with schizophrenia and prescribed antipsychotic medications. Higher quality reviews with greater strength and credibility of evidence are required. Uniform reporting of intervention elements is also necessary for cross comparison of efficacious elements and synthesis of evidence at higher levels to advance dietetic practice and inform future policies.

Exploring Therapeutic Potential of Phytoconstituents as a Gut Microbiota Modulator in the Management of Neurological and Psychological Disorders

The functioning of the brain and its impact on behavior, emotions, and cognition can be affected by both neurological and psychiatric disorders that impose a significant burden on global health. Phytochemicals are helpful in the treatment of several neurological and psychological disorders, including anxiety, depression, Huntington's disease (HD), Parkinson's disease (PD), Alzheimer's disease (AD), and autism spectrum disorder (ASD), because they have symptomatic benefits with few adverse reactions. Changes in gut microbiota have been associated with many neurological and psychiatric conditions. This review focuses on the potential efficacy of phytochemicals such as flavonoids, terpenoids, and polyphenols in regulating gut flora and providing symptomatic relief for a range of neurological and psychological conditions. Evidence-based research has shown the medicinal potentials of these phytochemicals, but additional study is required to determine whether altering gut microbiota might slow the advancement of neurological and psychological problems.

Add-On Bifidobacterium Bifidum Supplement in Children with Attention-Deficit/Hyperactivity Disorder: A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial

We conducted a 12-week randomized double-blind placebo-controlled clinical trial to investigate the potential impact of Bifidobacterium bifidum (Bf-688) supplementation on attention-deficit/hyperactivity disorder (ADHD). Children with ADHD who were already receiving a stable dose of methylphenidate (MPH) treatment were enrolled and were randomly assigned to two groups: one receiving add-on Bf-688 (daily bacterial count of 5 × 109 CFUs) (n = 51) and the other receiving a placebo (n = 51). All participants underwent assessments using Conners' Continuous Performance Test (CPT) and Conners' Continuous Auditory Test of Attention (CATA). Additionally, fecal samples were collected at the beginning of the trial (week 0) and at the endpoint (week 12). Remarkably, the group receiving Bf-688 supplementation, but not the placebo group, exhibited significant improvements in omission errors in CPT as well as Hit reaction time in both CPT and CATA. Gut microbiome analysis revealed a significant increase in the Firmicutes to Bacteroidetes ratio (F/B ratio) only in the Bf-688 group. Furthermore, we identified significant negative correlations between N-Glycan biosynthesis and Hit reaction time in both CPT and CATA. Our results demonstrate that the probiotic Bf-688 supplement can enhance neuropsychological performance in children with ADHD, possibly by altering the composition of the gut microbiota, ultimately leading to reduced N-Glycan biosynthesis.

Gestational diabetes mellitus: Impacts on fetal neurodevelopment, gut dysbiosis, and the promise of precision medicine

Gestational diabetes mellitus (GDM) is a common metabolic disorder affecting approximately 16.5% of pregnancies worldwide and causing significant health concerns. GDM is a serious pregnancy complication caused by chronic insulin resistance in the mother and has been associated with the development of neurodevelopmental disorders in offspring. Emerging data support the notion that GDM affects both the maternal and fetal microbiome, altering the composition and function of the gut microbiota, resulting in dysbiosis. The observed dysregulation of microbial presence in GDM pregnancies has been connected to fetal neurodevelopmental problems. Several reviews have focused on the intricate development of maternal dysbiosis affecting the fetal microbiome. Omics data have been instrumental in deciphering the underlying relationship among GDM, gut dysbiosis, and fetal neurodevelopment, paving the way for precision medicine. Microbiome-associated omics analyses help elucidate how dysbiosis contributes to metabolic disturbances and inflammation, linking microbial changes to adverse pregnancy outcomes such as those seen in GDM. Integrating omics data across these different layers-genomics, transcriptomics, proteomics, metabolomics, and microbiomics-offers a comprehensive view of the molecular landscape underlying GDM. This review outlines the affected pathways and proposes future developments and possible personalized therapeutic interventions by integrating omics data on the maternal microbiome, genetics, lifestyle factors, and other relevant biomarkers aimed at identifying women at high risk of developing GDM. For example, machine learning tools have emerged with powerful capabilities to extract meaningful insights from large datasets.

Male mice are susceptible to brain dysfunction induced by early-life acephate exposure

Background

Acephate is a widely used organophosphate insecticide. Exposure to endocrine-disrupting chemicals, such as acephate, can interfere with neurodevelopment in childhood, increasing the risk of higher brain dysfunction later in life. Furthermore, brain dysfunction may be related to chemical exposure-related disturbances in the gut microbiota. However, the effects of early acephate exposure on the brains of adult males and females as well as on the adult gut environment remain poorly understood.

Methods

This study investigated the effects of perinatal acephate exposure on the central nervous system and gut microbiota of mice, including sex differences and environmentally relevant concentrations. C57BL/6 N pups were exposed to acephate (0, 0.3, 10, and 300 ppm) via the dam in their drinking water from embryonic day (E) 11.5 to postnatal day 14. We examined its effects on the central nervous system of adult males and females.

Results

In the male treatment group, impairments in learning and memory were detected. Immunohistochemical analysis revealed a decrease in SOX2-, NeuN-, DCX-, and GFAP-positive cells in the hippocampal dentate gyrus in males compared to the control group, whereas GFAP-positive cells were fewer in females. In addition, gut microbiota diversity was reduced in both sexes in the experimental group.

Conclusion

Our study demonstrates that the effects of early-life exposure to acephate are more pronounced in males than in females and can lead to a lasting impact on adult behavior, even at low doses, and that the gut microbiota may reflect the brain environment.

Microbiota-brain axis: Exploring the role of gut microbiota in psychiatric disorders - A comprehensive review

Mental illness is a hidden epidemic in modern science that has gradually spread worldwide. According to estimates from the World Health Organization (WHO), approximately 10% of the world's population suffers from various mental diseases each year. Worldwide, financial and health burdens on society are increasing annually. Therefore, understanding the different factors that can influence mental illness is required to formulate novel and effective treatments and interventions to combat mental illness. Gut microbiota, consisting of diverse microbial communities residing in the gastrointestinal tract, exert profound effects on the central nervous system through the gut-brain axis. The gut-brain axis serves as a conduit for bidirectional communication between the two systems, enabling the gut microbiota to affect emotional and cognitive functions. Dysbiosis, or an imbalance in the gut microbiota, is associated with an increased susceptibility to mental health disorders and psychiatric illnesses. Gut microbiota is one of the most diverse and abundant groups of microbes that have been found to interact with the central nervous system and play important physiological functions in the human gut, thus greatly affecting the development of mental illnesses. The interaction between gut microbiota and mental health-related illnesses is a multifaceted and promising field of study. This review explores the mechanisms by which gut microbiota influences mental health, encompassing the modulation of neurotransmitter production, neuroinflammation, and integrity of the gut barrier. In addition, it emphasizes a thorough understanding of how the gut microbiome affects various psychiatric conditions.

Neurodevelopmental Disorders Associated with Gut Microbiome Dysbiosis in Children

The formation of the human gut microbiome initiates in utero, and its maturation is established during the first 2-3 years of life. Numerous factors alter the composition of the gut microbiome and its functions, including mode of delivery, early onset of breastfeeding, exposure to antibiotics and chemicals, and maternal stress, among others. The gut microbiome-brain axis refers to the interconnection of biological networks that allow bidirectional communication between the gut microbiome and the brain, involving the nervous, endocrine, and immune systems. Evidence suggests that the gut microbiome and its metabolic byproducts are actively implicated in the regulation of the early brain development. Any disturbance during this stage may adversely affect brain functions, resulting in a variety of neurodevelopmental disorders (NDDs). In the present study, we reviewed recent evidence regarding the impact of the gut microbiome on early brain development, alongside its correlation with significant NDDs, such as autism spectrum disorder, attention-deficit/hyperactivity disorder, Tourette syndrome, cerebral palsy, fetal alcohol spectrum disorders, and genetic NDDs (Rett, Down, Angelman, and Turner syndromes). Understanding changes in the gut microbiome in NDDs may provide new chances for their treatment in the future.

Placental Epigenome Impacts Fetal Development: Effects of Maternal Nutrients and Gut Microbiota

Evidence is emerging on the role of maternal diet, gut microbiota, and other lifestyle factors in establishing lifelong health and disease, which are determined by transgenerationally inherited epigenetic modifications. Understanding epigenetic mechanisms may help identify novel biomarkers for gestation-related exposure, burden, or disease risk. Such biomarkers are essential for developing tools for the early detection of risk factors and exposure levels. It is necessary to establish an exposure threshold due to nutrient deficiencies or other environmental factors that can result in clinically relevant epigenetic alterations that modulate disease risks in the fetus. This narrative review summarizes the latest updates on the roles of maternal nutrients (n-3 fatty acids, polyphenols, vitamins) and gut microbiota on the placental epigenome and its impacts on fetal brain development. This review unravels the potential roles of the functional epigenome for targeted intervention to ensure optimal fetal brain development and its performance in later life.

Antibiotic treatment induces microbiome dysbiosis and reduction of neuroinflammation following traumatic brain injury in mice

Background

The gut microbiome is linked to brain pathology in cases of traumatic brain injury (TBI), yet the specific bacteria that are implicated are not well characterized. To address this gap, in this study, we induced traumatic brain injury (TBI) in male C57BL/6J mice using the controlled cortical impact (CCI) injury model. After 35 days, we administered a broad-spectrum antibiotics (ABX) cocktail (ampicillin, gentamicin, metronidazole, vancomycin) through oral gavage for 2 days to diminish existing microbiota. Subsequently, we inflicted a second TBI on the mice and analyzed the neuropathological outcomes five days later.

Results

Longitudinal analysis of the microbiome showed significant shifts in the diversity and abundance of bacterial genera during both acute and chronic inflammation. These changes were particularly dramatic following treatment with ABX and after the second TBI. ABX treatment did not affect the production of short-chain fatty acids (SCFA) but did alter intestinal morphology, characterized by reduced villus width and a lower count of goblet cells, suggesting potential negative impacts on intestinal integrity. Nevertheless, diminishing the intestinal microbiome reduced cortical damage, apoptotic cell density, and microglial/macrophage activation in the cortical and thalamic regions of the brain.

Conclusions

Our findings suggest that eliminating colonized gut bacteria via broad-spectrum ABX reduces neuroinflammation and enhances neurological outcomes in TBI despite implications to gut health.

From the Microbiome to the Electrome: Implications for the Microbiota-Gut-Brain Axis

The gut microbiome plays a fundamental role in metabolism, as well as the immune and nervous systems. Microbial imbalance (dysbiosis) can contribute to subsequent physical and mental pathologies. As such, interest has been growing in the microbiota-gut-brain brain axis and the bioelectrical communication that could exist between bacterial and nervous cells. The aim of this study was to investigate the bioelectrical profile (electrome) of two bacterial species characteristic of the gut microbiome: a Proteobacteria Gram-negative bacillus Escherichia coli (E. coli), and a Firmicutes Gram-positive coccus Enterococcus faecalis (E. faecalis). We analyzed both bacterial strains to (i) validate the fluorescent probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol, DiBAC4(3), as a reliable reporter of the changes in membrane potential (Vmem) for both bacteria; (ii) assess the evolution of the bioelectric profile throughout the growth of both strains; (iii) investigate the effects of two neural-type stimuli on Vmem changes: the excitatory neurotransmitter glutamate (Glu) and the inhibitory neurotransmitter γ-aminobutyric acid (GABA); (iv) examine the impact of the bioelectrical changes induced by neurotransmitters on bacterial growth, viability, and cultivability using absorbance, live/dead fluorescent probes, and viable counts, respectively. Our findings reveal distinct bioelectrical profiles characteristic of each bacterial species and growth phase. Importantly, neural-type stimuli induce Vmem changes without affecting bacterial growth, viability, or cultivability, suggesting a specific bioelectrical response in bacterial cells to neurotransmitter cues. These results contribute to understanding the bacterial response to external stimuli, with potential implications for modulating bacterial bioelectricity as a novel therapeutic target.

Mind over Microbes: Investigating the Interplay between Lifestyle Factors, Gut Microbiota, and Brain Health

BACKGROUND

The gut microbiota (GM) of the human body comprises several species of microorganisms. This microorganism plays a significant role in the physiological and pathophysiological processes of various human diseases.

METHODS

The literature review includes studies that describe causative factors that influence GM. The GM is sensitive to various factors like circadian rhythms, environmental agents, physical activity, nutrition, and hygiene that together impact the functioning and composition of the gut microbiome. This affects the health of the host, including the psycho-neural aspects, due to the interconnectivity between the brain and the gut. Hence, this paper examines the relationship of GM with neurodegenerative disorders in the context of these aforesaid factors.

CONCLUSION

Future studies that identify the regulatory pathways associated with gut microbes can provide a causal link between brain degeneration and the gut at a molecular level. Together, this review could be helpful in designing preventive and treatment strategies aimed at GM, so that neurodegenerative diseases can be treated.

Application of Microbiome-Based Therapies in Chronic Respiratory Diseases

The application of microbiome-based therapies in various areas of human disease has recently increased. In chronic respiratory disease, microbiome-based clinical applications are considered compelling options due to the limitations of current treatments. The lung microbiome is ecologically dynamic and affected by various conditions, and dysbiosis is associated with disease severity, exacerbation, and phenotype as well as with chronic respiratory disease endotype. However, it is not easy to directly modulate the lung microbiome. Additionally, studies have shown that chronic respiratory diseases can be improved by modulating gut microbiome and administrating metabolites. Although the composition, diversity, and abundance of the microbiome between the gut and lung are considerably different, modulation of the gut microbiome could improve lung dysbiosis. The gut microbiome influences that of the lung via bacterial-derived components and metabolic degradation products, including short-chain fatty acids. This phenomenon might be associated with the cross-talk between the gut microbiome and lung, called gut-lung axis. There are multiple alternatives to modulate the gut microbiome, such as prebiotics, probiotics, and postbiotics ingestion and fecal material transplantation. Several studies have shown that high-fiber diets, for example, present beneficial effects through the production of short-chain fatty acids. Additionally, genetically modified probiotics to secrete some beneficial molecules might also be utilized to treat chronic respiratory diseases. Further studies on microbial modulation to regulate immunity and potentiate conventional pharmacotherapy will improve microbiome modulation techniques, which will develop as a new therapeutic area in chronic respiratory diseases.

Protective effects of fecal microbiota transplantation against ischemic stroke and other neurological disorders: an update

The bidirectional communication between the gut and brain or gut-brain axis is regulated by several gut microbes and microbial derived metabolites, such as short-chain fatty acids, trimethylamine N-oxide, and lipopolysaccharides. The Gut microbiota (GM) produce neuroactives, specifically neurotransmitters that modulates local and central neuronal brain functions. An imbalance between intestinal commensals and pathobionts leads to a disruption in the gut microbiota or dysbiosis, which affects intestinal barrier integrity and gut-immune and neuroimmune systems. Currently, fecal microbiota transplantation (FMT) is recommended for the treatment of recurrent Clostridioides difficile infection. FMT elicits its action by ameliorating inflammatory responses through the restoration of microbial composition and functionality. Thus, FMT may be a potential therapeutic option in suppressing neuroinflammation in post-stroke conditions and other neurological disorders involving the neuroimmune axis. Specifically, FMT protects against ischemic injury by decreasing IL-17, IFN-γ, Bax, and increasing Bcl-2 expression. Interestingly, FMT improves cognitive function by lowering amyloid-β accumulation and upregulating synaptic marker (PSD-95, synapsin-1) expression in Alzheimer's disease. In Parkinson's disease, FMT was shown to inhibit the expression of TLR4 and NF-κB. In this review article, we have summarized the potential sources and methods of administration of FMT and its impact on neuroimmune and cognitive functions. We also provide a comprehensive update on the beneficial effects of FMT in various neurological disorders by undertaking a detailed interrogation of the preclinical and clinical published literature.

Probiotics as modulators of gut-brain axis for cognitive development

Various microbial communities reside in the gastrointestinal tract of humans and play an important role in immunity, digestion, drug metabolism, intestinal integrity, and protection from pathogens. Recent studies have revealed that the gut microbiota (GM) is involved in communication with the brain, through a bidirectional communication network known as the gut-brain axis. This communication involves humoral, immunological, endocrine, and neural pathways. Gut dysbiosis negatively impacts these communication pathways, leading to neurological complications and cognitive deficits. Both pre-clinical and clinical studies have demonstrated that probiotics can restore healthy GM, reduce intestinal pH, and reduce inflammation and pathogenic microbes in the gut. Additionally, probiotics improve cell-to-cell signaling and increase blood-brain-derived neurotrophic factors. Probiotics emerge as a potential approach for preventing and managing neurological complications and cognitive deficits. Despite these promising findings, the safety concerns and possible risks of probiotic usage must be closely monitored and addressed. This review article provides a brief overview of the role and significance of probiotics in cognitive health.

Gut microbiota, nutrition, and mental health

The human brain remains one of the greatest challenges for modern medicine, yet it is one of the most integral and sometimes overlooked aspects of medicine. The human brain consists of roughly 100 billion neurons, 100 trillion neuronal connections and consumes about 20-25% of the body's energy. Emerging evidence highlights that insufficient or inadequate nutrition is linked to an increased risk of brain health, mental health, and psychological functioning compromise. A core component of this relationship includes the intricate dynamics of the brain-gut-microbiota (BGM) system, which is a progressively recognized factor in the sphere of mental/brain health. The bidirectional relationship between the brain, gut, and gut microbiota along the BGM system not only affects nutrient absorption and utilization, but also it exerts substantial influence on cognitive processes, mood regulation, neuroplasticity, and other indices of mental/brain health. Neuroplasticity is the brain's capacity for adaptation and neural regeneration in response to stimuli. Understanding neuroplasticity and considering interventions that enhance the remarkable ability of the brain to change through experience constitutes a burgeoning area of research that has substantial potential for improving well-being, resilience, and overall brain health through optimal nutrition and lifestyle interventions. The nexus of lifestyle interventions and both academic and clinical perspectives of nutritional neuroscience emerges as a potent tool to enhance patient outcomes, proactively mitigate mental/brain health challenges, and improve the management and treatment of existing mental/brain health conditions by championing health-promoting dietary patterns, rectifying nutritional deficiencies, and seamlessly integrating nutrition-centered strategies into clinical care.

Analysis of the gut microbiome in sled dogs reveals glucosamine- and activity-related effects on gut microbial composition

The composition of the microbiome influences many aspects of physiology and health, and can be altered by environmental factors, including diet and activity. Glucosamine is a dietary supplement often administered to address arthritic symptoms in humans, dogs, and other mammals. To investigate how gut microbial composition varies with glucosamine supplementation, we performed 16S rRNA sequence analysis of fecal samples from 24 Alaskan and Inuit huskies and used mixed effects models to investigate associations with activity, age, and additional factors. Glucosamine ingestion, age, activity, sex, and diet were correlated with differences in alpha-diversity, with diversity decreasing in dogs consuming glucosamine. Beta-diversity analysis revealed clustering of dogs based on glucosamine supplementation status. Glucosamine supplementation and exercise-related activity were associated with greater inter-individual pairwise distances. At the family level, Lactobacillaceae and Anaerovoracaceae relative abundances were lower in supplemented dogs when activity was accounted for. At the genus level, Eubacterium [brachy], Sellimonus, Parvibacter, and an unclassified genus belonging to the same family as Parvibacter (Eggerthellaceae) all were lower in supplemented dogs, but only significantly so post-activity. Our findings suggest that glucosamine supplementation alters microbiome composition in sled dogs, particularly in the context of exercise-related activity.

Stress, Environment and Early Psychosis

Existing literature provides extended evidence of the close relationship between stress dysregulation, environmental insults, and psychosis onset. Early stress can sensitize genetically vulnerable individuals to future stress, modifying their risk for developing psychotic phenomena. Neurobiological substrate of the aberrant stress response to hypothalamic-pituitary-adrenal axis dysregulation, disrupted inflammation processes, oxidative stress increase, gut dysbiosis, and altered brain signaling, provides mechanistic links between environmental risk factors and the development of psychotic symptoms. Early-life and later-life exposures may act directly, accumulatively, and repeatedly during critical neurodevelopmental time windows. Environmental hazards, such as pre- and perinatal complications, traumatic experiences, psychosocial stressors, and cannabis use might negatively intervene with brain developmental trajectories and disturb the balance of important stress systems, which act together with recent life events to push the individual over the threshold for the manifestation of psychosis. The current review presents the dynamic and complex relationship between stress, environment, and psychosis onset, attempting to provide an insight into potentially modifiable factors, enhancing resilience and possibly influencing individual psychosis liability.

Microglia and Microbiome-Gut-Brain Axis

The mammalian gut contains a community of microorganisms called gut microbiome. The gut microbiome is integrated into mammalian physiology, contributing to metabolism, production of metabolites, and promoting immunomodulatory actions. Microglia, the brain's resident innate immune cells, play an essential role in homeostatic neurogenesis, synaptic remodeling, and glial maturation. Microglial dysfunction has been implicated in the pathogenesis of several neuropsychiatric disorders. Recent findings indicate that microglia are influenced by the gut microbiome and their derived metabolites throughout life. The pathways by which microbiota regulate microglia have only started to be understood, but this discovery has the potential to provide valuable insights into the pathogenesis of brain disorders associated with an altered microbiome. Here, we discuss the recent literature on the role of the gut microbiome in modulating microglia during development and adulthood and summarize the key findings on this bidirectional crosstalk in selected examples of neuropsychiatric and neurodegenerative disorders. We also highlight some current caveats and perspectives for the field.