Gut brain axis: diet microbiota interactions and implications for modulation of anxiety and depression. Curr Opin Biotechnol. 2015;32:35-41. [PMID: 25448230 DOI: 10.1016/j.copbio.2014.10.007]

Human Milk Oligosaccharide LNnT Promotes Intestinal Epithelial Growth and Maturation During the Early Life of Infant Mice

Lacto-N-neotetraose (LNnT) is a prevalent neutral core human milk oligosaccharides (HMOs) recognized for its numerous benefits to infant health. In infant formula, galactooligosaccharide (GOS) are frequently used as substitutes for HMOs. However, the regulatory roles of LNnT and GOS in early intestinal development are not yet fully understood. This study aims to elucidate the effects of LNnT and GOS on intestinal development during early life. Our findings show that administering LNnT or GOS significantly increased the spleen and liver indices of infant mice at postnatal day 21. Immunofluorescence and qPCR analysis showed that feeding LNnT significantly promoted the proliferation and differentiation of intestinal stem cells (ISCs) in the colon of infant mice at postnatal day 21, and increased the expression of differentiation markers of goblet cells, intestinal epithelial cells, Paneth cells, and intestinal endocrine cells. Conversely, feeding GOS had no significant effect on the proliferation and differentiation of ISCs. Furthermore, intestinal microbiota analysis showed that LNnT increased the microbiota associated with intestinal regeneration and ISCs proliferation and differentiation in infant mice at postnatal day 21. In conclusion, LNnT promoted ISCs proliferation and differentiation in the colon and alters the composition and function of the intestinal microbiota to support intestinal development in infant mice.

The "brain-gut" mechanism of postherpetic neuralgia: a mini-review

Postherpetic neuralgia (PHN), a representative type of neuropathic pain, has attracted much research on its diagnosis and therapy at the molecular level. Interestingly, this study based on the brain-gut axis provided a novel point of view to interpret the mechanism of PHN. Past neuroanatomical and neuroimaging studies of pain suggest that the prefrontal cortex, anterior cingulate cortex, amygdala, and other regions of the brain may play crucial roles in the descending inhibition of PHN. Dominant bacterial species in patients with PHN, such as Lactobacillus, generate short-chain fatty acids, including butyrate. Evidence indicates that disturbance of some metabolites (such as butyrate) is closely related to the development of hyperalgesia. In addition, tryptophan and 5-HT in the intestinal tract act as neurotransmitters that regulate the descending transmission of neuropathic pain signals. Concurrently, the enteric nervous system establishes close connections with the central nervous system through the vagus nerve and other pathways. This review aims to investigate and elucidate the molecular mechanisms associated with PHN, focusing on the interplay among PHN, the gut microbiota, and relevant metabolites while scrutinizing its pathogenesis.

DS0384 Alleviates Necrotizing Enterocolitis: Secretes N-carbamyl glutamic Acid and Participates in Lipid Metabolism and Lipid Peroxidation Processes

Necrotizing enterocolitis (NEC) is a life-threatening inflammatory bowel disease linked to gut microbiome dysbiosis. This study evaluates the efficacy of Limosilactobacillus reuteri strain DS0384, which secretes N-carbamyl glutamic acid (NCG), in modulating lipid peroxidation and inflammatory pathways in NEC. After pretreatment with DS0384, NEC mouse model was induced by gavage with bacteria-containing formula. NCG levels in the ileum were measured via CE-TOFMS metabolomic analysis. Additionally, rat small intestinal epithelial IEC-6 cells were exposed to lipopolysaccharide (LPS), treated with DS0384 DNA (D-DNA), and/or transfected to overexpress fatty acid synthase (FASN) and Toll-like receptor 4 (TLR4). Lipid peroxidation, peroxidation and inflammatory factors and NF-κB pathways were analysed. Immunofluorescence was used to measure the expression levels of ZO-1 and TLR4 in the ileum. DS0384 treatment significantly reduced more histological abnormalities, apoptosis, and TLR4 expression in NEC mice, while restoring NCG levels, downregulating FASN and inhibiting lipid peroxidation and inflammation. Pre-treatment with D-DNA maintained cell vitality, reduced apoptosis, and suppressed TLR4/NF-κB-mediated inflammasome activation. Overexpression of FASN or TLR4 reversed these effects. DS0384 is a promising therapeutic against NEC, enhancing gut barrier integrity and modulating inflammatory and oxidative responses, suggesting potential clinical benefits in preventing NEC progression.

A bibliometric analysis of research on dementia comorbid with depression from 2005 to 2024

Introduction

With the global rise in life expectancy, the incidence of dementia is increasing, often accompanied by depressive symptoms. Understanding the interplay between dementia and depression is crucial, as depression may not only co-occur with but also potentially exacerbate the progression of dementia. This study employs bibliometric analysis to map the global research landscape, identify prevailing themes, and discern future research directions.

Methods

We analyzed reviews and original research articles on dementia and depression extracted from the Web of Science Core Collection spanning from 2005 to 2024. Utilizing tools such as CiteSpace, VOSviewer, and an R-based bibliometric analysis package, we assessed trends in publication volume, citation frequency, contributing countries, leading institutions, predominant journals, influential authors, and emergent keywords.

Results

A total of 1972 publications were obtained, revealing a consistent increase in both the number of publications and their citation impact over the study period. The United States is the country with the most publications and the most extensive collaborations. The University of Toronto and the Journal of Alzheimer's Disease were identified as key contributors to this field. This research area is currently focused on cognitive impairments, the role of gut microbiota, and non-drug interventions. Future directions emphasize the importance of early detection and intervention, a deeper understanding of the gut-brain axis, and the integration of technology in treatment strategies. Additionally, there is a growing interest in the physiological and psychological interplays such as oxidative stress and its implications.

Conclusion

This study underscores pathogenesis, comorbid conditions, and non-drug interventions as primary research focal points, suggesting these areas as potential pathways for therapeutic innovation. These insights are intended to deepen our understanding, enhance diagnostics, and improve the management of dementia and depression, providing guidance for future research aimed at addressing these escalating global health challenges.

Exploring the Multifaceted Therapeutic Potential of Probiotics: A Review of Current Insights and Applications

The interplay between human health and the microbiome has gained extensive attention, with probiotics emerging as pivotal therapeutic agents due to their vast potential in treating various health issues. As significant modulators of the gut microbiota, probiotics are crucial in maintaining intestinal homeostasis and enhancing the synthesis of short-chain fatty acids. Despite extensive research over the past decades, there remains an urgent need for a comprehensive and detailed review that encapsulates probiotics' latest insights and applications. This review focusses on the multifaceted roles of probiotics in promoting health and preventing disease, highlighting the complex mechanisms through which these beneficial bacteria influence both gut flora and the human body at large. This paper also explores probiotics' neurological and gastrointestinal applications, focussing on their significant impact on the gut-brain axis and their therapeutic potential in a broad spectrum of pathological conditions. Current innovations in probiotic formulations, mainly focusing on integrating genomics and biotechnological advancements, have also been comprehensively discussed herein. This paper also critically examines the regulatory landscape that governs probiotic use, ensuring safety and efficacy in clinical and dietary settings. By presenting a comprehensive overview of recent studies and emerging trends, this review aims to illuminate probiotics' extensive therapeutic capabilities, leading to future research and clinical applications. However, besides extensive research, further advanced explorations into probiotic interactions and mechanisms will be essential for developing more targeted and effective therapeutic strategies, potentially revolutionizing health care practices for consumers.

Advances in neuroscience research and big data's analysis on anxiety disorder

Anxiety disorder is a complex disease with the influence of environmental and genetic factors and multimolecular participation, and it is also one of the most common mental disorders. The causes of disorders are not clear but may include a variety of social, psychological, and biological factors. Therefore, neither genetics, neurobiology, nor neuroimaging can independently explain the pathological mechanism. By searching the Web of Science databases, Derwent Innovation Patent database, ClinicalTrials.gov database, and Cortellis database, we analyze the current situation of papers, patents, clinical trials, and drugs of anxiety disorder. Second, the existing literature was reviewed to summarize the neurophysiological mechanism, brain imaging, gene, anti-anxiety drugs, and other aspects of anxiety disorders. This article reviews the research status of anxiety disorders. The heterogeneity of the disease, lack of treatment effectiveness, and gaps in translational medicine still present barriers to further advancement. Thus, in-depth explorations of the underlying biological mechanisms of anxiety disorders, the detection and intervention of biological targets, and further developments based on existing intervention strategies will drive future research on anxiety disorders. This article is categorized under: Neuroscience > Clinical.

The Impact of Lactobacillus reuteri on Oral and Systemic Health: A Comprehensive Review of Recent Research

Oral diseases, particularly dental caries and periodontal disease, pose significant global health challenges. The imbalance of the oral microbiota plays a key role in the occurrence of these diseases, prompting researchers to seek new strategies to restore oral ecological balance. Lactobacillus reuteri is a Gram-positive rod-shaped bacterium that exists in various body parts of humans, including the gastrointestinal tract, urinary tract, skin, and so on. This species has a potentially positive impact on oral health and plays an important role in maintaining systemic health. Recent studies have explored the application of Lactobacillus reuteri in the prevention and treatment of oral diseases, and its impact on systemic health has also been preliminarily revealed. The current review summarizes the role of Lactobacillus reuteri in oral health and systemic health and outlines its potential applications in the future. Lactobacillus reuteri has shown promising prospects in treating non-communicable biofilm-dependent oral diseases, but its mechanism of action and efficacy still need further research. In addition, Lactobacillus reuteri has also displayed some potential benefits in promoting overall health. Future research should focus on revealing the specific pathways of action of Lactobacillus reuteri, screening for the most beneficial strains, determining the most effective drug delivery strategies, developing oral and systemic health products based on Lactobacillus reuteri, and ensuring their safety in clinical applications.

Nutritional Modulation of the Gut-Brain Axis: A Comprehensive Review of Dietary Interventions in Depression and Anxiety Management

Mental health is an increasing topic of focus since more than 500 million people in the world suffer from depression and anxiety. In this multifactorial disorder, parameters such as inflammation, the state of the microbiota and, therefore, the patient's nutrition are receiving more attention. In addition, food products are the source of many essential ingredients involved in the regulation of mental processes, including amino acids, neurotransmitters, vitamins, and others. For this reason, this narrative review was carried out with the aim of analyzing the role of nutrition in depression and anxiety disorders. To reach the review aim, a critical review was conducted utilizing both primary sources, such as scientific publications and secondary sources, such as bibliographic indexes, web pages, and databases. The search was conducted in PsychINFO, MedLine (Pubmed), Cochrane (Wiley), Embase, and CinAhl. The results show a direct relationship between what we eat and the state of our nervous system. The gut-brain axis is a complex system in which the intestinal microbiota communicates directly with our nervous system and provides it with neurotransmitters for its proper functioning. An imbalance in our microbiota due to poor nutrition will cause an inflammatory response that, if sustained over time and together with other factors, can lead to disorders such as anxiety and depression. Changes in the functions of the microbiota-gut-brain axis have been linked to several mental disorders. It is believed that the modulation of the microbiome composition may be an effective strategy for a new treatment of these disorders. Modifications in nutritional behaviors and the use of ergogenic components are presented as important non-pharmacological interventions in anxiety and depression prevention and treatment. It is desirable that the choice of nutritional and probiotic treatment in individual patients be based on the results of appropriate biochemical and microbiological tests.

Deciphering relationship between depression and microbial molecules based on multi-omics: A case study of Chaigui Granules

Objective

To decipher the antidepression effect of Chaigui Granules (CGKL) from the relationship between depression and microbial molecules based on multi-omics.

Methods

Male SD rats were subjected to chronic unpredictable mild stress (CUMS) for seven weeks. The antidepressants CGKL extract and CGKL were administered for the following four weeks. The behavior test and the content of monoamine neurotransmitters were used to evaluate the efficacy of CGKL. The 16S rRNA sequencing, LC-MS technology and molecular biological techniques were used to explore the pharmacological mechanism of CGKL.

Results

CGKL treatment obviously alleviated the depressive behavioral indicators and regulated the content of monoamine neurotransmitters, and presented dose-dependent manner. CGKL could also improve the arginine metabolism disorder of gut microbiota in the jejunum. Meanwhile, the contents of arginine and its metabolites in the serum and hippocampus were regulated to normal levels. Further investigation indicated that the expression of related rate-limiting enzyme genes and proteins in the hippocampus was validated by qRT-PCR and Western blotting. The results showed that the gut microbiota, metabolites, and genes or proteins of rate-limiting enzymes involved in the arginine pathway were significantly regulated by CGKL.

Conclusion

The present study demonstrates that CGKL might exert antidepressant effects through regulating arginine metabolism, and its mechanism may be related to modulating the gut microbiota and related metabolic enzyme.

Exploring the gut-brain Axis: Potential therapeutic impact of Psychobiotics on mental health

One of the most challenging and controversial issues in microbiome research is related to gut microbial metabolism and neuropsychological disorders. Psychobiotics affect human behavior and central nervous system processes via the gut-brain axis, involving neuronal, immune, and metabolic pathways. They have therapeutic potential in the treatment of several neurodegenerative and neurodevelopmental disorders such as depression, anxiety, autism, attention deficit hyperactivity disorder, Alzheimer's disease, Parkinson's disease, schizophrenia, Huntington's disease, anorexia nervosa, and multiple sclerosis. However, the mechanisms underlying the interaction between psychobiotics and the abovementioned diseases need further exploration. This review focuses on the relationship between gut microbiota and its impact on neurological and neurodegenerative disorders, examining the potential of psychobiotics as a preventive and therapeutic approach, summarising recent research on the gut-brain axis and the potential beneficial effects of psychobiotics, highlighting the need for further research and investigation in this area.

Differences in the human gut microbiota with varying depressive symptom severity scores

Depression is a prevalent mental health disorder, and its incidence has increased further because of the coronavirus disease 2019 (COVID-19) pandemic. The gut microbiome has been suggested as a potential target for mental health treatment because of the bidirectional communication system between the brain and gastrointestinal tract, known as the gut-brain axis. We aimed to investigate the relationship between the human gut microbiome and depression screening by analyzing the abundance and types of microbiomes among individuals living in Japan, where mental health awareness and support may differ from those in other countries owing to cultural factors. We used a data-driven approach to evaluate the gut microbiome of participants who underwent commercial gut microbiota testing services and completed a questionnaire survey that included a test for scoring depressive tendencies. Our data analysis results indicated that no significant differences in gut microbiome composition were found among the groups based on their depression screening scores. However, the results also indicated the potential existence of a few differentially abundant bacterial taxa. Specifically, the detected bacterial changes in abundance suggest that the Bifidobacteriaceae, Streptococcaceae, and Veillonellaceae families are candidates for differentially abundant bacteria. Our findings should contribute to the growing body of research on the relationship between gut microbiome and mental health, highlighting the potential of microbiome-based interventions for depression treatment. The limitations of this study include the lack of clear medical information on the participants' diagnoses. Future research could benefit from a larger sample size and more detailed clinical information.

Psychobiotics Lactiplantibacillus plantarum JYLP-326: Antidepressant-like effects on CUMS-induced depressed mouse model and alleviation of gut microbiota dysbiosis

BACKGROUND

Depression affects a significant portion of the global population and has emerged as one of the most debilitating conditions worldwide. Recent studies have explored the relationship between depression and the microbiota of the intestine, revealing potential avenues for effective treatment.

METHODS

To evaluate the potential alleviation of depression symptoms, we employed a depression C57BL/6 mice model induced by chronic unpredictable mild stress (CUMS). We administered Lactiplantibacillus plantarum JYLP-326 and conducted various animal behavior tests, including the open-field test (OFT), sucrose preference test (SPT), and tail-suspension test (TST). Additionally, we conducted immunohistochemistry staining and analyzed the hippocampal and colon parts of the mice.

RESULTS

The results of the behavior tests indicated that L. plantarum JYLP-326 alleviated spontaneous behavior associated with depression. Moreover, the treatment led to significant improvements in GFAP and Iba1, suggesting its potential neuroprotective effects. Analysis of the hippocampal region indicated that L. plantarum JYLP-326 administration upregulated p-TPH2, TPH2, and 5-HT1AR, while downregulating the expression of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. In the colon, the treatment inhibited the TLR4-MyD88-NF-κB pathway and increased the levels of occludin and ZO-1, indicating improved intestinal barrier function. Additionally, the probiotic demonstrated a regulatory effect on the HMGB1-RAGE-TLR4 signaling pathway.

CONCLUSIONS

Our findings demonstrate that L. plantarum JYLP-326 exhibits significant antidepressant-like effects in mice, suggesting its potential as a therapeutic approach for depression through the modulation of gut microbiota. However, further investigations and clinical trials are required to validate its safety and efficacy for human use.

Associations between memory performance and Bifidobacterium pseudolongum abundance in the canine gut microbiome

Memory has been identified as the least heritable cognitive trait in canines, suggesting a significant influence of non-genetic factors. We observed a trend that overall memory scores (OMS) improve with age in a cohort of 27 young dogs, but considerable plasticity exists. Employing linear discriminant analysis of gut microbiome data from dogs exhibiting low and high OMS, a single bacterial species, Bifidobacterium pseudolongum, was identified and confirmed to be correlated with elevated OMS. Subsequent analysis using a random forest regression model revealed that sex, litter, and breed identity had minimal predictive importance. Age had some predictive value but failed to achieve statistical significance in this dataset. In sharp contrast, the abundance of 17 bacterial taxa in the microbiome showed a stronger predictive capacity for memory performance. Our findings provide insights into microbiome underpinnings of mammalian cognitive functions and suggest avenues for developing psychobiotics to enhance canine memory and learning.

Gut microbiome-based therapies for alleviating cognitive impairment: state of the field, limitations, and future perspectives

Cognitive impairment (CI) is a multifaceted neurological condition that can trigger negative emotions and a range of concurrent symptoms, imposing significant public health and economic burdens on society. Therefore, it is imperative to discover a remedy for CI. Nevertheless, the mechanisms behind the onset of this disease are multifactorial, which makes the search for effective amelioration difficult and complex, hindering the search for effective measures. Intriguingly, preclinical research indicates that gut microbiota by influencing brain function, plays an important role in the progression of CI. Furthermore, numerous preclinical studies have highlighted the potential of probiotics, prebiotics, fecal microbiota transplantation (FMT), and diet in modulating the gut microbiota, thereby ameliorating CI symptoms. This review provides a comprehensive evaluation of CI pathogenesis, emphasizing the contribution of gut microbiota disorders to CI development. It also summarizes and discusses current strategies and mechanisms centered on the synergistic role of gut microbiota modulation in the microbiota-gut-brain axis in CI development. Finally, problems with existing approaches are contemplated and the development of microbial modulation strategies as therapeutic approaches to promote and restore brain cognition is discussed. Further research considerations and directions are highlighted to provide ideas for future CI prevention and treatment strategies.

BDNF/CREB signaling pathway contribution in depression pathogenesis: A survey on the non-pharmacological therapeutic opportunities for gut microbiota dysbiosis

Emerging evidence supports the gut microbiota and the brain communication in general health. This axis may affect behavior through modulating neurotransmission, and thereby involve in the pathogenesis and/or progression of different neuropsychiatric disorders such as depression. Brain-derived neurotrophic factor and cAMP response element-binding protein known as CREB/BDNF pathway plays have critical functions in the pathogenesis of depression as the same of mechanisms related to antidepressants. However, the putative causal significance of the CREB/BDNF signaling cascade in the gut-brain axis in depression remains unknown. Also interventions such as probiotics supplementation and exercise can influence microbiome also improve bidirectional communication of gut and brain. In this review we aim to explain the BDNF/CREB signaling pathway and gut microbiota dysfunction and then evaluate the potential role of probiotics, prebiotics, and exercise as a therapeutic target in the gut microbiota dysfunction induced depression. The current narrative review will specifically focus on the impact of exercise and diet on the intestinal microbiota component, as well as the effect that these therapies may have on the microbiota to alleviate depressive symptoms. Finally, we look at how BDNF/CREB signaling pathway may exert distinct effects on depression and gut microbiota dysfunction.

Akkermansia muciniphila Improves Depressive-Like Symptoms by Modulating the Level of 5-HT Neurotransmitters in the Gut and Brain of Mice

Accumulating evidence has suggested that the gut microbiome plays an important role in depression. Akkermansia muciniphila (AKK), a next-generation probiotic, shows a beneficial effect on immune and metabolic homeostasis. The relative abundance of AKK was found negatively correlated with depressive symptoms in both clinical and pre-clinical studies. To evaluate the potential antidepressant effect of AKK and explore the possible mechanism, we used chronic alcohol exposure and chronic unpredictable mild stress (CUMS) to induce depressive-like behaviors in mice. We found that oral AKK administration significantly reduced the immobility time in the force swimming test (FST) and tail suspension test (TST) in the mice with chronic alcohol exposure and the CUMS mice. The sucrose preference in the mice receiving AKK was significantly increased in the sucrose preference test (SPT). More importantly, AKK implantation significantly increased the level of 5-HT in the gut and PFC of both the alcohol exposure mice and the CUMS mice. Furthermore, AKK had inhibited the expression of SERT in the gut but not in the brain for both NIAAA and the CUMS model mice. Interestingly, the expression of cFos in enteric nerves in the gut significantly decreased after AKK administration. In conclusion, our study demonstrated the antidepressant effect of AKK in mice exposed to alcohol exposure and CUMS, with the potential mechanism that AKK implantation might lead to an increased level of 5-HT and inhibited SERT expression in the gut, and might alter the gut-to-brain signal through suppression of enteric nerves activation.

Nutrition and Mental Well-Being: Exploring Connections and Holistic Approaches

Quality of life, well-being, and psycho-emotional balance are closely related to the quality of the diet, the level of physical activity, the quality of rest, but also the absence of the consumption of narcotic substances and tobacco, or alcohol abuse. Based on the distribution of a questionnaire that included 30 questions, we aimed to statistically evaluate several factors that influence mental health and vices. It recorded a total of 1719 valid responses, which came from 78.3% female respondents and 21.7% male respondents. After processing the anthropometric data, it was observed that the majority of respondents are of normal weight (63.87%) and come from women in particular (36.13%). Based on the answers recorded, although over 60% of the respondents participating in the study are up to 40 years old, there is an increased tendency towards sedentarism (over 58% of the respondents declaring that they do sports very rarely or not at all), a low tendency regarding optimal consumption of vegetables and fruits, many respondents do not hydrate properly, which is why approximately 60% of respondents feel frequently tired, and over 32% are frequently nervous. The increased level of stress among the respondents and emotional eating are also generated by inadequate rest, reduced physical activity, and a diet that does not help the efficient detoxification of the body.

Nutritional considerations in major depressive disorder: current evidence and functional testing for clinical practice

Depression is a multifaceted condition with diverse underlying causes. Several contributing and inter-related factors such as genetic, nutritional, neurological, physiological, gut-brain-axis, metabolic and psychological stress factors play a role in the pathophysiology of depression. This review aims to highlight the role that nutritional factors play in the aetiology of depression. Secondly, we discuss the biomedical and functional pathology tests which measure these factors, and the current evidence supporting their use. Lastly, we make recommendations on how practitioners can incorporate the latest evidence-based research findings into clinical practice. This review highlights that diet and nutrition greatly affect the pathophysiology of depression. Nutrients influence gene expression, with folate and vitamin B12 playing vital roles in methylation reactions and homocysteine regulation. Nutrients are also involved in the tryptophan/kynurenine pathway and the expression of brain-derived neurotrophic factor (BDNF). Additionally, diet influences the hypothalamic-pituitary-adrenal (HPA) response and the composition and diversity of the gut microbiome, both of which have been implicated in depression. A comprehensive dietary assessment, combined with appropriate evaluation of biochemistry and blood pathology, may help uncover contributing factors to depressive symptoms. By employing such an approach, a more targeted and personalised treatment strategy can be devised, ultimately leading to improved patient outcomes.

From-Toilet-to-Freezer: A Review on Requirements for an Automatic Protocol to Collect and Store Human Fecal Samples for Research Purposes

The composition, viability and metabolic functionality of intestinal microbiota play an important role in human health and disease. Studies on intestinal microbiota are often based on fecal samples, because these can be sampled in a non-invasive way, although procedures for sampling, processing and storage vary. This review presents factors to consider when developing an automated protocol for sampling, processing and storing fecal samples: donor inclusion criteria, urine-feces separation in smart toilets, homogenization, aliquoting, usage or type of buffer to dissolve and store fecal material, temperature and time for processing and storage and quality control. The lack of standardization and low-throughput of state-of-the-art fecal collection procedures promote a more automated protocol. Based on this review, an automated protocol is proposed. Fecal samples should be collected and immediately processed under anaerobic conditions at either room temperature (RT) for a maximum of 4 h or at 4 °C for no more than 24 h. Upon homogenization, preferably in the absence of added solvent to allow addition of a buffer of choice at a later stage, aliquots obtained should be stored at either -20 °C for up to a few months or -80 °C for a longer period-up to 2 years. Protocols for quality control should characterize microbial composition and viability as well as metabolic functionality.

The potential modulation of gut microbiota and oxidative stress by dietary carotenoid pigments

Gut microbiota plays a crucial role in regulating the response to immune checkpoint therapy, therefore modulation of the microbiome with bioactive molecules like carotenoids might be a very effective strategy to reduce the risk of chronic diseases. This review highlights the bio-functional effect of carotenoids on Gut Microbiota modulation based on a bibliographic search of the different databases. The methodology given in the preferred reporting items for systematic reviews and meta-analyses (PRISMA) has been employed for developing this review using papers published over two decades considering keywords related to carotenoids and gut microbiota. Moreover, studies related to the health-promoting properties of carotenoids and their utilization in the modulation of gut microbiota have been presented. Results showed that there can be quantitative changes in intestinal bacteria as a function of the type of carotenoid. Due to the dependency on several factors, gut microbiota continues to be a broad and complex study subject. Carotenoids are promising in the modulation of Gut Microbiota, which favored the appearance of beneficial bacteria, resulting in the protection of villi and intestinal permeability. In conclusion, it can be stated that carotenoids may help to protect the integrity of the intestinal epithelium from pathogens and activate immune cells.

Kombucha: Challenges for Health and Mental Health

BACKGROUND

Increasing research into probiotics is showing potential benefits for health in general and mental health in particular. Kombucha is a recent beverage and can be considered a probiotic drink, but little is known about its effects on physical and mental health. This product is experiencing growth in the market; however, there are no scientific results to support its potential for physical and mental health.

AIM

This review article aims to draw attention to this issue and to highlight the lack of studies in this area.

KEY FINDINGS AND CONCLUSIONS

The lack of legislation for the correct marketing of this product may also constrain clinical studies. However, clinical studies are of utmost importance for an in-depth understanding of the effects of this product on the human body. More research is needed, not only to better understand the impact of Kombucha on the human body, but also to ensure the application of regulatory guidelines for its production and marketing and enable its safe and effective consumption.

Microbiome: The Next Frontier in Psychedelic Renaissance

The psychedelic renaissance has reignited interest in the therapeutic potential of psychedelics for mental health and well-being. An emerging area of interest is the potential modulation of psychedelic effects by the gut microbiome-the ecosystem of microorganisms in our digestive tract. This review explores the intersection of the gut microbiome and psychedelic therapy, underlining potential implications for personalized medicine and mental health. We delve into the current understanding of the gut-brain axis, its influence on mood, cognition, and behavior, and how the microbiome may affect the metabolism and bioavailability of psychedelic substances. We also discuss the role of microbiome variations in shaping individual responses to psychedelics, along with potential risks and benefits. Moreover, we consider the prospect of microbiome-targeted interventions as a fresh approach to boost or modulate psychedelic therapy's effectiveness. By integrating insights from the fields of psychopharmacology, microbiology, and neuroscience, our objective is to advance knowledge about the intricate relationship between the microbiome and psychedelic substances, thereby paving the way for novel strategies to optimize mental health outcomes amid the ongoing psychedelic renaissance.

Systems biology approaches to identify potential targets and inhibitors of the intestinal microbiota to treat depression

Depression is a common mental disease, with some patients exhibiting ideas and behaviors such as self-harm and suicide. The drugs currently used to treat depression have not achieved good results. It has been reported that metabolites produced by intestinal microbiota affect the development of depression. In this study, core targets and core compounds were screened by specific algorithms in the database, and three-dimensional structures of these compounds and proteins were simulated by molecular docking and molecular dynamics software to further study the influence of intestinal microbiota metabolites on the pathogenesis of depression. By analyzing the RMSD gyration radius and RMSF, it was finally determined that NR1H4 had the best binding effect with genistein. Finally, according to Lipinski's five rules, equol, genistein, quercetin and glycocholic acid were identified as effective drugs for the treatment of depression. In conclusion, the intestinal microbiota can affect the development of depression through the metabolites equol, genistein and quercetin, which act on the critical targets of DPP4, CYP3A4, EP300, MGAM and NR1H4.

Protective effects of Liupao tea against high-fat diet/cold exposure-induced irritable bowel syndrome in rats

Liupao tea as a type of dark tea can relieve irritable bowel syndrome by regulating gut microbiota, but the mechanism has not been fully explained. An ultra-high performance liquid chromatography along with quadrupole time of flight tandem mass spectrometry was used to analyze the phytochemicals in Liupao tea. Then, we explored the effects of Liupao tea against IBS. From the results of chemical analysis, we identified catechins, polyphenols, amino acids, caffeine, polysaccharides and other components in Liupao tea. The open-field test, gastrointestinal function-related indexes, histochemical assays, measurements of cytokine and aquaporin 3 (AQP3), and determination of serum metabolites were utilized to monitor the physiological consequences of Liupao tea administration in rats with irritable bowel syndrome. The results showed that Liupao tea had a significant protective effect on irritable bowel syndrome. Liupao tea increased locomotive velocity while reducing interleukin-6, interleukin-1β, and tumor necrosis factor-α levels, as well as gastrointestinal injury. Moreover, Liupao tea increased the AQP3 levels of renal tissues but reduced the AQP3 levels of gastrointestinal tissues. Liupao tea reduced the Firmicutes/Bacteroides ratio and significantly reconstructed the microbial pattern. Liupao tea relieved irritable bowel syndrome by repairing gastrointestinal dysfunction, regulating the secretion of pro-inflammatory cytokines, modulating water metabolism, and restoring microbial homeostasis.

The Muscle-Gut-Brain Axis and Psychiatric Illness

The microbiota-gut-brain axis (MGBA) has been the subject of much research over the past decade, offering an exciting new paradigm for the treatment of psychiatric disorders. In this review, the MGBA is extended to include skeletal muscle and the potential role of an expanded "muscle-gut-brain axis" (MuGBA) in conditions such as anxiety and depression is discussed. There is evidence, from both preclinical and human studies, of bidirectional links between the gut microbiome and skeletal muscle function and structure. The therapeutic role of exercise in reducing depressive and anxiety symptoms is widely recognised, and the potential role of the gut microbiota-skeletal muscle link is discussed within this context. Potential pathways of communication involved in the MuGBA including the tryptophan-kynurenine pathway, intestinal permeability, immune modulation, and bacterial metabolites such as short-chain-fatty-acids are explored.

Probiotics therapy show significant improvement in obesity and neurobehavioral disorders symptoms

Obesity is a complex metabolic disease, with cognitive impairment being an essential complication. Gut microbiota differs markedly between individuals with and without obesity. The microbial-gut-brain axis is an important pathway through which metabolic factors, such as obesity, affect the brain. Probiotics have been shown to alleviate symptoms associated with obesity and neurobehavioral disorders. In this review, we evaluated previously published studies on the effectiveness of probiotic interventions in reducing cognitive impairment, depression, and anxiety associated with obesity or a high-fat diet. Most of the probiotics studied have beneficial health effects on obesity-induced cognitive impairment and anxiety. They positively affect immune regulation, the hypothalamic-pituitary-adrenal axis, hippocampal function, intestinal mucosa protection, and glucolipid metabolism regulation. Probiotics can influence changes in the composition of the gut microbiota and the ratio between various flora. However, probiotics should be used with caution, particularly in healthy individuals. Future research should further explore the mechanisms underlying the gut-brain axis, obesity, and cognitive function while overcoming the significant variation in study design and high risk of bias in the current evidence.

Microbiota from Preterm Infants Who Develop Necrotizing Enterocolitis Drives the Neurodevelopment Impairment in a Humanized Mouse Model

Necrotizing enterocolitis (NEC) is the leading basis for gastrointestinal morbidity and poses a significant risk for neurodevelopmental impairment (NDI) in preterm infants. Aberrant bacterial colonization preceding NEC contributes to the pathogenesis of NEC, and we have demonstrated that immature microbiota in preterm infants negatively impacts neurodevelopment and neurological outcomes. In this study, we tested the hypothesis that microbial communities before the onset of NEC drive NDI. Using our humanized gnotobiotic model in which human infant microbial samples were gavaged to pregnant germ-free C57BL/6J dams, we compared the effects of the microbiota from preterm infants who went on to develop NEC (MNEC) to the microbiota from healthy term infants (MTERM) on brain development and neurological outcomes in offspring mice. Immunohistochemical studies demonstrated that MNEC mice had significantly decreased occludin and ZO-1 expression compared to MTERM mice and increased ileal inflammation marked by the increased nuclear phospho-p65 of NFκB expression, revealing that microbial communities from patients who developed NEC had a negative effect on ileal barrier development and homeostasis. In open field and elevated plus maze tests, MNEC mice had worse mobility and were more anxious than MTERM mice. In cued fear conditioning tests, MNEC mice had worse contextual memory than MTERM mice. MRI revealed that MNEC mice had decreased myelination in major white and grey matter structures and lower fractional anisotropy values in white matter areas, demonstrating delayed brain maturation and organization. MNEC also altered the metabolic profiles, especially carnitine, phosphocholine, and bile acid analogs in the brain. Our data demonstrated numerous significant differences in gut maturity, brain metabolic profiles, brain maturation and organization, and behaviors between MTERM and MNEC mice. Our study suggests that the microbiome before the onset of NEC has negative impacts on brain development and neurological outcomes and can be a prospective target to improve long-term developmental outcomes.

Protective Effects of Kefir Against Unpredictable Chronic Stress Alterations in Mice Central Nervous System, Heart, and Kidney

Kefir is a probiotic mixture with anxiolytic and antioxidant properties. Chronic stress can lead to anxiety disorders and increase oxidative damage in organs such as the heart and kidney. In this study, we examined whether kefir ameliorates the anxiety-like behavior of mice submitted to chronic unpredictable stress (CUS) by modulating brain-derived neurotrophic factor (BDNF) and corticosterone levels and whether kefir modifies the oxidative parameters in the heart and kidney of mice. Male Swiss mice received kefir (0.3 mL/100 g/day) or milk for 30 days (gavage). On the 10th day, the mice were submitted to CUS. Behavioral analysis was performed using the elevated plus maze and forced swimming tests. BDNF levels were analyzed in brain tissues. Heart and kidney superoxide dismutase (SOD), catalase, glutathione (GSH), thiobarbituric acid reactive substances (TBARS), 3-nitrotyrosine, metalloproteinase-2 (MMP-2), and plasma corticosterone were evaluated. Kefir reverted the CUS-induced decrease in the time spent in the open arms, the increase in grooming frequency, and decrease in the head dipping frequency, but not the reduced immobility time. CUS decreased the cerebellum BDNF levels and increased corticosterone levels, which were restored by Kefir. Neither catalase and SOD activities nor GSH, TBARS, 3-nitrotyrosine, and MMP-2 were modified by CUS in the heart. In the kidney, CUS increased 3-nitrotyrosine and MMP-2. Kefir increased the antioxidant defense in the heart and kidney of control and CUS mice. These results suggest that kefir ameliorated CUS-induced anxiety-like behavior by modulating brain BDNF and corticosterone levels. Kefir also increased the antioxidant defense of mice heart and kidney.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Tryptophol Acetate and Tyrosol Acetate, Small-Molecule Metabolites Identified in a Probiotic Mixture, Inhibit Hyperinflammation

Probiotic fermented foods are perceived as contributing to human health; however, solid evidence for their presumptive therapeutic systemic benefits is generally lacking. Here we report that tryptophol acetate and tyrosol acetate, small-molecule metabolites secreted by the probiotic milk-fermented yeast Kluyveromyces marxianus, inhibit hyperinflammation (e.g., "cytokine storm"). Comprehensive in vivo and in vitro analyses, employing LPS-induced hyperinflammation models, reveal dramatic effects of the molecules, added in tandem, on mice morbidity, laboratory parameters, and mortality. Specifically, we observed attenuated levels of the proinflammatory cytokines IL-6, IL-1α, IL-1β, and TNF-α and reduced reactive oxygen species. Importantly, tryptophol acetate and tyrosol acetate did not completely suppress proinflammatory cytokine generation, rather brought their concentrations back to baseline levels, thus maintaining core immune functions, including phagocytosis. The anti-inflammatory effects of tryptophol acetate and tyrosol acetate were mediated through downregulation of TLR4, IL-1R, and TNFR signaling pathways and increased A20 expression, leading to NF-kB inhibition. Overall, this work illuminates phenomenological and molecular details underscoring anti-inflammatory properties of small molecules identified in a probiotic mixture, pointing to potential therapeutic avenues against severe inflammation.

Gut microbiota mediates the pharmacokinetics of Zhi-zi-chi decoction for the personalized treatment of depression

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-zi-chi decoction (ZZCD), from "Treatise on Febrile Diseases", is a typical traditional Chinese medicine herb pair, which consists of Gardeniae Fructus (GF) and Semen Sojae Praeparatu (SSP). In clinical research, ZZCD was widely used to fight depression, remove annoyance. Many studies have reported that gut microbiota is critical target for the influence of depress through gut-brain axis, and our previously studies have found that ZZCD exhibiting antidepressant effect was through the gut-brain axis. However, the specific mechanism by which gut microbiota mediates the pharmacokinetics parameters of active compounds from ZZCD during the process of depression treatment has not yet been studied.

AIM OF THE STUDY

To explore the differences in pharmacokinetics characters of bioactive iridoids from ZZCD and study the changes of gut microbiota at different stages of depression with the personalized medicine of ZZCD.

MATERIALS AND METHODS

A new strategy exploring the relationship among disease phenotypes (D), intestinal microbiota (I), enzymes (E) and traits of metabolism (T) named as "DIET" was established. Firstly, a fast, selective and sensitive ultra-performance liquid chromatography coupled with tandem mass spectrometer (UPLC-MS/MS) was established and validated to quality the main bioactive compounds from ZZCD and compare the pharmacokinetics and bioavailability of different iridoids prototypes and metabolites from ZZCD between normal and chronic unpredictable mild stress rats. Subsequently, the activity of corresponding metabolic enzymes of anti-depressive compounds, β-glucosidases and sulfotransferases, were analyzed by ρ-nitrophenyl-β -D-glucopyranoside and sulfotransferases ELISA kits, respectively. Finally, 16S rRNA gene sequencing was adopt to analyze intestinal bacteria composition for the treatment of depression by ZZCD.

RESULTS

The antidepressant effect of ZZCD was promoted due to the increased exposures and reduced eliminations of anti-depressive compounds, especially geniposide and genipin 1-gentiobioside, under the depression state. With the ZZCD treatment, the depression was improved, but the exposures of anti-depressive compounds from ZZCD gradually decreased. Meanwhile, there were the corresponding decreased trends on the activity of β-glucosidases and sulfotransferases. With the consumption of ZZDC and the improvement of depression, the exposures of anti-depressive iridoid glycosides decreased and the activity of metabolism enzymes restored. Meanwhile, the dysbiosis of pathogenic bacteria (Bacteroidota) induced by depression was ameliorated and the probiotics (Firmicutes) at the phylum and genus level raised, the two phyla are closely related to the production of β-glucosidase and sulfotransferases.

CONCLUSIONS

It is the first proposed that ZZCD could personalized to treat depression at different stages targeting gut microbiota and gut microbiome could emerged as a potential diagnostic and therapeutic biomarker in depression.

Limosilactobacillus reuteri administration alters the gut-brain-behavior axis in a sex-dependent manner in socially monogamous prairie voles

Research on the role of gut microbiota in behavior has grown dramatically. The probiotic L. reuteri can alter social and stress-related behaviors - yet, the underlying mechanisms remain largely unknown. Although traditional laboratory rodents provide a foundation for examining the role of L. reuteri on the gut-brain axis, they do not naturally display a wide variety of social behaviors. Using the highly-social, monogamous prairie vole (Microtus ochrogaster), we examined the effects of L. reuteri administration on behaviors, neurochemical marker expression, and gut-microbiome composition. Females, but not males, treated with live L. reuteri displayed lower levels of social affiliation compared to those treated with heat-killed L. reuteri. Overall, females displayed a lower level of anxiety-like behaviors than males. Live L. reuteri-treated females had lower expression of corticotrophin releasing factor (CRF) and CRF type-2-receptor in the nucleus accumbens, and lower vasopressin 1a-receptor in the paraventricular nucleus of the hypothalamus (PVN), but increased CRF in the PVN. There were both baseline sex differences and sex-by-treatment differences in gut microbiome composition. Live L. reuteri increased the abundance of several taxa, including Enterobacteriaceae, Lachnospiraceae NK4A136, and Treponema. Interestingly, heat-killed L. reuteri increased abundance of the beneficial taxa Bifidobacteriaceae and Blautia. There were significant correlations between changes in microbiota, brain neurochemical markers, and behaviors. Our data indicate that L. reuteri impacts gut microbiota, gut-brain axis and behaviors in a sex-specific manner in socially-monogamous prairie voles. This demonstrates the utility of the prairie vole model for further examining causal impacts of microbiome on brain and behavior.

Neurodevelopmental outcome of infants who develop necrotizing enterocolitis: The gut-brain axis

Necrotizing enterocolitis (NEC) poses a significant risk for neurodevelopmental impairment in extremely preterm infants. The gut microbiota shapes the development of the gut, immune system, and the brain; and dysbiosis drive neonatal morbidities including NEC. In this chapter, we delineate a gut-brain axis linking gut microbiota to the adverse neurological outcomes in NEC patients. We propose that in NEC, immaturity of the microbiome along with aberrant gut microbiota-driven immaturity of the gut barrier and immune system can lead to effects including systemic inflammation and circulating microbial mediators. This nexus of gut microbiota-driven systemic effects further interacts with a likewise underdeveloped blood-brain barrier to regulate neuroinflammation and neurodevelopment. Targeting deviant gut-brain axis signaling presents an opportunity to improve the neurodevelopmental outcomes of NEC patients.

Neuromicrobiology, an emerging neurometabolic facet of the gut microbiome?

The concept of the gut microbiome is emerging as a metabolic interactome influenced by diet, xenobiotics, genetics, and other environmental factors that affect the host's absorption of nutrients, metabolism, and immune system. Beyond nutrient digestion and production, the gut microbiome also functions as personalized polypharmacy, where bioactive metabolites that our microbes excrete or conjugate may reach systemic circulation and impact all organs, including the brain. Appreciable evidence shows that gut microbiota produce diverse neuroactive metabolites, particularly neurotransmitters (and their precursors), stimulating the local nervous system (i.e., enteric and vagus nerves) and affecting brain function and cognition. Several studies have demonstrated correlations between the gut microbiome and the central nervous system sparking an exciting new research field, neuromicrobiology. Microbiome-targeted interventions are seen as promising adjunctive treatments (pre-, pro-, post-, and synbiotics), but the mechanisms underlying host-microbiome interactions have yet to be established, thus preventing informed evidence-based therapeutic applications. In this paper, we review the current state of knowledge for each of the major classes of microbial neuroactive metabolites, emphasizing their biological effects on the microbiome, gut environment, and brain. Also, we discuss the biosynthesis, absorption, and transport of gut microbiota-derived neuroactive metabolites to the brain and their implication in mental disorders.

Microbiota-Gut-Brain Axis in Major Depression: A New Therapeutic Approach

Major depression is impacted by the disruption of gut microbiota. Defects in gut microbiota can lead to microbiota-gut-brain axis dysfunction and increased vulnerability to major depression. While traditional chemotherapeutic approaches, such as antidepressant use, produce an overall partial therapeutic effect on depression, the gut microbiome has emerged as an effective target for better therapeutic outcomes. Recent representative studies on the microbiota hypothesis to explore the association between gut pathophysiology and major depression have indicated that restoring gut microbiota and microbiota-gut-brain axis could alleviate depression. We reviewed studies that supported the gut microbiota hypothesis to better understand the pathophysiology of depression; we also explored reports suggesting that gut microbiota restoration is an effective approach for improving depression. These findings indicate that gut microbiota and microbiota-gut-brain axis are appropriate new therapeutic targets for major depression.

[The regulatory role of gut microbiota in inflammation in depression and anxiety]

Numerous studies have identified the important role of the gut microbiota in maintaining of the CNS normal functioning and in the pathogenesis of mental disorders as one of the systems regulating the bidirectional communication between the gut and the brain. The microbiota has been found to be involved in the modulation of inflammation as well as in the development and function of the immune and nervous systems. It is assumed that in multicellular organisms, the nervous and immune systems have evolved together with the microbiota, being in interaction with it, in order to optimize the body's ability to adapt to a wide range of environmental stresses in order to maintain the constancy of its homeostasis. Normally, microbes live in stable communities, while under conditions of even mild or chronic social stress, significant shifts in the composition of the microbiota occur, which lead to the development of dysbiosis associated with changes in microbiota metabolites, which can lead to the formation of physiology and behavior characteristic of stress and depression. Microbes influence the activation of peripheral immune cells that regulate the response to neuroinflammation, brain damage, autoimmune responses, and neurogenesis. The review provides a brief overview of the normal gut microbiota, describes the factors influencing the state of the microbiota, and also discusses recent discoveries concerning the regulatory effect of the gut microbiota on CNS functions, the immune system, and inflammation in the pathogenesis of depression and anxiety.

Modulatory Effect of Gut Microbiota on the Gut-Brain, Gut-Bone Axes, and the Impact of Cannabinoids

The gut microbiome is a collection of microorganisms and parasites in the gastrointestinal tract. Many factors can affect this community's composition, such as age, sex, diet, medications, and environmental triggers. The relationship between the human host and the gut microbiota is crucial for the organism's survival and development, whereas the disruption of this relationship can lead to various inflammatory diseases. Cannabidiol (CBD) and tetrahydrocannabinol (THC) are used to treat muscle spasticity associated with multiple sclerosis. It is now clear that these compounds also benefit patients with neuroinflammation. CBD and THC are used in the treatment of inflammation. The gut is a significant source of nutrients, including vitamins B and K, which are gut microbiota products. While these vitamins play a crucial role in brain and bone development and function, the influence of gut microbiota on the gut-brain and gut-bone axes extends further and continues to receive increasing scientific scrutiny. The gut microbiota has been demonstrated to be vital for optimal brain functions and stress suppression. Additionally, several studies have revealed the role of gut microbiota in developing and maintaining skeletal integrity and bone mineral density. It can also influence the development and maintenance of bone matrix. The presence of the gut microbiota can influence the actions of specific T regulatory cells, which can lead to the development of bone formation and proliferation. In addition, its metabolites can prevent bone loss. The gut microbiota can help maintain the bone's equilibrium and prevent the development of metabolic diseases, such as osteoporosis. In this review, the dual functions gut microbiota plays in regulating the gut-bone axis and gut-brain axis and the impact of CBD on these roles are discussed.

A comprehensive study on the relieving effect of Lilium brownii on the intestinal flora and metabolic disorder in p-chlorphenylalanine induced insomnia rats

CONTEXT

The bulb of Lilium brownii F. E. Brown (Liliaceae) (LB) is a common Chinese medicine to relieve insomnia.

OBJECTIVE

To investigate the molecular mechanism of LB relieving insomnia.

MATERIALS AND METHODS

Insomnia model was induced by intraperitoneally injection p-chlorophenylalanine (PCPA) in Wistar rats. Rats were divided into three groups: Control, PCPA (400 mg/kg, i.p. 2 days), LB (598.64 mg/kg, oral 7 days). The levels of 5-hydroxytryptamine (5-HT), norepinephrine (NE), melatonin (MT), and the expression of GABA_A, 5-HT1A and MT receptors, as well as pathological changes in hypothalamus, were evaluated. 16S rDNA sequencing and UPLC-MS/MS were used to reveal the change of the intestinal flora and metabolic profile.

RESULTS

The adverse changes in the abundance and diversity of intestinal flora and faecal metabolic phenotype altered by PCPA in rats were reversed after LB treatment, accompanied by the up-regulated levels of 5-HT as 8.14 ng/mL, MT as 16.16 pg/mL, 5-HT1A R and GABA_A R, down-regulated level of NE as 0.47 ng/mL, and the improvement of pathological phenomena of cells in the hypothalamus. And the arachidonic acid metabolism and tryptophan metabolism pathway most significantly altered by PCPA were markedly regulated by LB. Besides, it was also found that LB reduced the levels of kynurenic acid related to psychiatric disorders and trimethylamine-N-oxide associated with cardiovascular disease.

CONCLUSION

The mechanism of LB relieving insomnia involves regulating flora and metabolites to resemble the control group. As a medicinal and edible herb, LB could be considered for development as a health-care food to relieve increasing insomniacs in the future.

Antidepressive Effect of Natural Products and Their Derivatives Targeting BDNF-TrkB in Gut-Brain Axis

Modern neurological approaches enable detailed studies on the pathophysiology and treatment of depression. An imbalance in the microbiota-gut-brain axis contributes to the pathogenesis of depression. This extensive review aimed to elucidate the antidepressive effects of brain-derived neurotrophic factor (BDNF)-targeting therapeutic natural products and their derivatives on the gut-brain axis. This information could facilitate the development of novel antidepressant drugs. BDNF is crucial for neuronal genesis, growth, differentiation, survival, plasticity, and synaptic transmission. Signaling via BDNF and its receptor tropomyosin receptor kinase B (TrkB) plays a vital role in the etiopathogenesis of depression and the therapeutic mechanism of antidepressants. This comprehensive review provides information to researchers and scientists for the identification of novel therapeutic approaches for neuropsychiatric disorders, especially depression and stress. Future research should aim to determine the possible causative role of BDNF-TrkB in the gut-brain axis in depression, which will require further animal and clinical research as well as the development of analytical approaches.

Limosilactobacillus reuteri DS0384 promotes intestinal epithelial maturation via the postbiotic effect in human intestinal organoids and infant mice

Little is known about the modulatory capacity of the microbiota in early intestinal development. We examined various intestinal models that respond to gut microbial metabolites based on human pluripotent stem cell-derived human intestinal organoids (hIOs): physiologically relevant in vitro fetal-like intestine, intestinal stem cell, and intestinal disease models. We found that a newly isolated Limosilactobacillus reuteri strain DS0384 accelerated maturation of the fetal intestine using 3D hIO with immature fetal characteristics. Comparative metabolomic profiling analysis revealed that the secreted metabolite N-carbamyl glutamic acid (NCG) is involved in the beneficial effect of DS0384 cell-free supernatants on the intestinal maturation of hIOs. Experiments in an intestinal stem cell spheroid model and hIO-based intestinal inflamed model revealed that the cell-free supernatant from DS0384 comprising NCG promoted intestinal stem cell proliferation and was important for intestinal protection against cytokine-induced intestinal epithelial injury. The probiotic properties of DS0384 were also evaluated, including acid and bile tolerance and ability to adhere to human intestinal cells. Seven-day oral administration of DS0384 and cell-free supernatant promoted the intestinal development of newborn mice. Moreover, NCG exerted a protective effect on experimental colitis in mice. These results suggest that DS0384 is a useful agent for probiotic applications and therapeutic treatment for disorders of early gut development and for preventing intestinal barrier dysfunction.

Meals, Microbiota and Mental Health in Children and Adolescents (MMM-Study): A protocol for an observational longitudinal case-control study

Recent studies indicate that the interplay between diet, intestinal microbiota composition, and intestinal permeability can impact mental health. More than 10% of children and adolescents in Iceland suffer from mental disorders, and rates of psychotropics use are very high. The aim of this novel observational longitudinal case-control study, "Meals, Microbiota and Mental Health in Children and Adolescents (MMM-Study)" is to contribute to the promotion of treatment options for children and adolescents diagnosed with mental disorders through identification of patterns that may affect the symptoms. All children and adolescents, 5-15 years referred to the outpatient clinic of the Child and Adolescent Psychiatry Department at The National University Hospital in Reykjavik, Iceland, for one year (n≈150) will be invited to participate. There are two control groups, i.e., sex-matched children from the same postal area (n≈150) and same parent siblings (full siblings) in the same household close in age +/- 3 years (n<150). A three-day food diary, rating scales for mental health, and multiple questionnaires will be completed. Biosamples (fecal-, urine-, saliva-, blood samples, and buccal swab) will be collected and used for 16S rRNA gene amplicon sequencing of the oral and gut microbiome, measurements of serum factors, quantification of urine metabolites and host genotype, respectively. For longitudinal follow-up, data collection will be repeated after three years in the same groups. Integrative analysis of diet, gut microbiota, intestinal permeability, serum metabolites, and mental health will be conducted applying bioinformatics and systems biology approaches. Extensive population-based data of this quality has not been collected before, with collection repeated in three years' time, contributing to the high scientific value. The MMM-study follows the "Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) guidelines. Approval has been obtained from the Icelandic National Bioethics Committee, and the study is registered with Clinicaltrials.gov. The study will contribute to an improved understanding of the links between diet, gut microbiota and mental health in children through good quality study design by collecting information on multiple components, and a longitudinal approach. Furthermore, the study creates knowledge on possibilities for targeted and more personalized dietary and lifestyle interventions in subgroups. Trial registration numbers: VSN-19-225 & NCT04330703.

Marked shifts in gut microbial structure and neurotransmitter metabolism in fresh inmates revealed a close link between gut microbiota and mental health: A case-controlled study

Background/Objective

The gut microbiota plays a pivotal role in psychological health, but the mechanistic perspective between gut microbiome and mental health remains poorly understood

Method

The present case-controlled study recruited 30 unimprisoned subjects and 31 inmates that had been detained in jail for no more than a month. The mental health status, gut microbiota and blood NH3, H2S, 5-hydroxy trptamine and dopamine levels were measured.

Results

Compared with unimprisoned controls, the fresh inmates exhibited significantly higher scores on anxiety and depression. Both phylogenetic structure and functional genes of the gut microbiota markedly shifted in inmates. Inmates was more Bacteroides-dominated, while unimprisoned subjects were more Prevotella-dominated. Short-chain fatty acids (SCFAs)-producing genera were largely decreased in inmates and were negatively related to mental disorder scores, while Bacteroidetes and Proteobacteria were positive to anxiety and depression scores. Simultaneously, the inmates possessed reduced genes that participate in amino acids, carbohydrates and vitamin cofactors metabolism, but enriched genes that involved in the neurotransmitter-producing Shikimate pathway. Correlation analysis revealed that Anaerotruncus and Prevotella were negative to depression score, and Enterococcus was negative to anxiety score.

Conclusions

Our results revealed potential link between gut microbiota and mental health, leading further support to the microbiota–gut–brain axis theory.

ROLE OF GUT MICROBIOTA IN DEPRESSION: UNDERSTANDING MOLECULAR PATHWAYS, RECENT RESEARCH, AND FUTURE DIRECTION

Gut microbiota, also known as the "second brain" in humans because of the regulatory role it has on the central nervous system via neuronal, chemical and immune pathways. It has been proven that there exists a bidirectional communication between the gut and the brain. Increasing evidence supports that this crosstalk is linked to the etiology and treatment of depression. Reports suggest that the gut microbiota control the host epigenetic machinery in depression and gut dysbiosis causes negative epigenetic modifications via mechanisms like histone acetylation, DNA methylation and non-coding RNA mediated gene inhibition. The gut microbiome can be a promising approach for the management of depression. The diet and dietary metabolites like kynurenine, tryptophan, and propionic acid also greatly influence the microbiome composition and thereby, the physiological activities. This review gives a bird-eye view on the pathological updates and currently used treatment approaches targeting the gut microbiota in depression.

Modulation of gut microbiota by bioactive compounds for prevention and management of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia and insulin resistance. Gut microbiota (GM) are specific groups of microbes colonized in the gastrointestinal (GI) tract. They profoundly influence health, disease protection, and associated with metabolic activities, and play a vital role in the production of functional metabolites from dietary substances. Dysbiosis of GM has been linked to the onset of T2DM and can be altered to attain eubiosis by intervention with various nutritional bioactive compounds such as polyphenols, prebiotics, and probiotics. This review presents an overview of the evidence and underlying mechanisms by which bioactive compounds modulate the GM for the prevention and management of T2DM.

The effects of probiotics on risk and time preferences

Animal models, human neuroimaging and lesion studies revealed that the gut microbiota can influence the interaction between the central and the enteric nervous systems via the gut–brain axis (GBA) and can affect brain regions linked to basic emotional and cognitive processes. The role of the gut microbiota in decision-making in healthy humans thus far remains largely unknown. Our study establishes a functional relationship between the gut microbiota and healthy humans’ decisions that involve risk and time. We conducted a between subjects’ placebo-controlled double-blinded design, with two groups and two sessions separated by 28 days, during which participants received daily doses of probiotics or a placebo. We investigated whether the prolonged and controlled intake of probiotics affects risk-taking behavior and intertemporal choices using incentivized economic tasks. We found a significant decrease in risk-taking behavior and an increase in future-oriented choices in the probiotics group as compared to the placebo group. These findings provide the first direct experimental evidence suggesting a potential functional role on the part of the microbiota-gut-brain axis in decision-making, creating a path for potential clinical applications and allowing for a better understanding of the underlying neural mechanisms of risk-taking behavior and intertemporal choices.

Synbiotic Effects of Fermented Rice on Human Health and Wellness: A Natural Beverage That Boosts Immunity

Fermented foods have been an important component of the human diet from the time immemorial. It contains a high amount of probiotics that have been associated to a wide range of health benefits, including improved digestion and immunity. This review focuses on the indigenously prepared prebiotic- and probiotic-containing functional fermented rice (named Xaj-pani) by the Ahom Community from Assam, in Northeast India, including all the beneficial and potential effects on human health. Literature was searched from scientific databases such as PubMed, ScienceDirect and Google Scholar. Glutinous rice (commonly known as bora rice of sali variety) is primarily employed to prepare beverages that are recovered through the filtration process. The beer is normally consumed during religious rites, festivals and ritual practices, as well as being used as a refreshing healthy drink. Traditionally, it is prepared by incorporating a variety of medicinal herbs into their starter culture (Xaj-pitha) inoculum which is rich in yeasts, molds and lactic acid bacteria (LAB) and then incorporated in alcoholic beverage fermentation. The Ahom communities routinely consume this traditionally prepared alcoholic drink with no understanding of its quality and shelf life. Additionally, a finally produced dried cake, known as vekur pitha act as a source of Saccharomyces cerevisiae and can be stored for future use. Despite the rampant use in this community, the relationship between Xaj-pani's consumption, immunological response, infectious and inflammatory processes remains unknown in the presence of factors unrelated or indirectly connected to immune function. Overall, this review provides the guidelines to promote the development of prebiotic- and probiotic-containing functional fermented rice that could significantly have an impact on the health of the consumers.

The Intervention of Prebiotics on Depression via the Gut-Brain Axis

The imbalance of intestinal microbiota can cause the accumulation of endotoxin in the main circulation system of the human body, which has a great impact on human health. Increased work and life pressure have led to a rise in the number of people falling into depression, which has also reduced their quality of life. The gut–brain axis (GBA) is closely related to the pathological basis of depression, and intestinal microbiota can improve depressive symptoms through GBA. Previous studies have proven that prebiotics can modulate intestinal microbiota and thus participate in human health regulation. We reviewed the regulatory mechanism of intestinal microbiota on depression through GBA, and discussed the effects of prebiotics, including plant polysaccharides and polyphenols on the regulation of intestinal microbiota, providing new clues for the prevention and treatment of depression.

Clinical, gut microbial and neural effects of a probiotic add-on therapy in depressed patients: a randomized controlled trial

A promising new treatment approach for major depressive disorder (MDD) targets the microbiota-gut-brain (MGB) axis, which is linked to physiological and behavioral functions affected in MDD. This is the first randomized controlled trial to determine whether short-term, high-dose probiotic supplementation reduces depressive symptoms along with gut microbial and neural changes in depressed patients. Patients with current depressive episodes took either a multi-strain probiotic supplement or placebo over 31 days additionally to treatment-as-usual. Assessments took place before, immediately after and again four weeks after the intervention. The Hamilton Depression Rating Sale (HAM-D) was assessed as primary outcome. Quantitative microbiome profiling and neuroimaging was used to detect changes along the MGB axis. In the sample that completed the intervention (probiotics N = 21, placebo N = 26), HAM-D scores decreased over time and interactions between time and group indicated a stronger decrease in the probiotics relative to the placebo group. Probiotics maintained microbial diversity and increased the abundance of the genus Lactobacillus, indicating the effectivity of the probiotics to increase specific taxa. The increase of the Lactobacillus was associated with decreased depressive symptoms in the probiotics group. Finally, putamen activation in response to neutral faces was significantly decreased after the probiotic intervention. Our data imply that an add-on probiotic treatment ameliorates depressive symptoms (HAM-D) along with changes in the gut microbiota and brain, which highlights the role of the MGB axis in MDD and emphasizes the potential of microbiota-related treatment approaches as accessible, pragmatic, and non-stigmatizing therapies in MDD. Trial Registration: www.clinicaltrials.gov , identifier: NCT02957591.

Perspective: Chicken Models for Studying the Ontogenetic Origin of Neuropsychiatric Disorders

Nutrients and xenobiotics cross the blood–placenta barrier, potentially depositing in the fetal brain. The prenatal exposure affects the neuroendocrine and microbial development. The mechanism underlying maternal risk factors reprograming the microbiota–gut–brain axis with long-term effects on psychosocial behaviors in offspring is not clear. In humans, it is not possible to assess the nutrient or xenobiotic deposition in the fetal brain and gastrointestinal system for ethical reasons. Moreover, the maternal–fetal microbe transfer during gestation, natural labor, and breast-feeding constitutes the initial gut microbiome in the progeny, which is inevitable in the most widely utilized rodent models. The social predisposition in precocial birds, including chickens, provides the possibility to test behavioral responses shortly after being hatched. Hence, chickens are advantageous in investigating the ontogenetic origin of behaviors. Chicken embryos are suitable for deposition assessment and mechanistic study due to the accessibility, self-contained development, uniform genetic background, robust microbiota, and easy in vivo experimental manipulation compared to humans and rodents. Therefore, chicken embryos can be used as an alternative to the rodent models in assessing the fetal exposure effect on neurogenesis and investigating the mechanism underlying the ontogenetic origin of neuropsychiatric disorders.

Influence of 2'-Fucosyllactose and Bifidobacterium longum Subspecies infantis Supplementation on Cognitive and Structural Brain Development in Young Pigs

Development of the gut-brain axis during early-life is an important contributor of brain structural and functional development. Human milk oligosaccharides and gut microbiota have potential beneficial effects on various aspects of development; however, the effects of 2′-fucosyllactose (2′-FL) and Bifidobacterium longum subsp. infantis Bi-26 (Bi-26) administration during infancy separately and combined are still not clear. Therefore, we investigated the effects of early administration of dietary 2′-FL and Bi-26 on brain structural and functional development in the young pig. From postnatal day (PND) 2–34 or 35, fifty-two intact male pigs were randomly assigned to treatment groups in a 2 × 2 factorial arrangement and provided ad libitum access to a nutritionally adequate milk replacer without or with 1.0 g of 2′-FL/L of reconstituted liquid. Pigs within each diet group were further stratified to receive a daily oral dose of glycerol stock without or with Bi-26 (10⁹ CFU). Pigs were subjected to the novel object recognition (NOR) task from PND 27–31 to assess recognition memory and subsequently underwent magnetic resonance imaging procedures at PND 32 or 33 to assess brain macrostructure and microstructure. Pigs that received Bi-26 had smaller absolute brain volumes for 9 of 27 brain regions of interest, and smaller relative volumes for 2 regions associated with kinesthesia (P < 0.05). Synbiotic administration of 2′-FL and Bi-26 elicited interactive effects (P < 0.05) on several microstructural brain components, where dual supplementation negated the effects of each test article alone. Behavioral outcomes indicated that pigs did not express novelty preference, regardless of treatment group, demonstrating no effects of 2′-FL and Bi-26 on recognition memory when supplemented alone or in combination. Interactive effects (P < 0.05) were observed for the number of all object visits, latency to the first object visit, and number of familiar object visits. Pigs that did not receive Bi-26 supplementation exhibited less time interacting with the familiar object in total (P = 0.002) and on average (P = 0.005). In conclusion, supplementation of 2′-FL and/or Bi-26 elicited some alterations in object exploratory behaviors and macro/micro-structures of the brain, but changes in recognition memory were not observed. Specifically in brain microstructure, synbiotic administration of 2′-FL and Bi-26 appeared to negate effects observed when each dietary article was supplemented separately.