Gut inflammation and dysbiosis in human motor neuron disease

Altered microbiome influence on the enteric neuromuscular system in amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a neurological disease marked by the degeneration of motor neurons, leading to muscle weakness and paralysis. While the cause of ALS is uncertain, research indicates that changes in the gut microbiome may influence the disease's progression. This chapter explores how alterations in gut microbiota affect the enteric neuromuscular system (ENS) in ALS. In ALS patients, disrupted gut microbiota are linked to the brain-gut axis, impacting both gastrointestinal function and neuronal health. Studies show that microbial changes are associated with inflammation, immune instability, and neurodegeneration, which exacerbate the disease. Gastrointestinal issues like constipation and dysphagia in ALS are tied to ENS dysregulation. Understanding the connections between the gut microbiome, ENS, and central nervous system (CNS) may lead to novel therapies targeting neurodegeneration and microbial dysbiosis in ALS.

Unlocking the therapeutic potential of gut microbiota for preventing and treating aging-related neurological disorders

Billions of microorganisms inhabit the human gut and maintain overall health. Recent research has revealed the intricate interaction between the brain and gut microbiota through the microbiota-gut-brain axis (MGBA) and its effect on neurodegenerative disorders (NDDs). Alterations in the gut microbiota, known as gut dysbiosis, are linked to the development and progression of several NDDs. Studies suggest that the gut microbiota may be a viable target for improving cognitive health and reducing hallmarks of brain aging. Numerous pathways including hypothalamic-pituitary-adrenal axis stimulation, neurotransmitter release disruption, system-wide inflammation, and increased intestinal and blood-brain barrier permeability connect gut dysbiosis to neurological conditions. Metabolites produced by the gut microbiota influence neural processes that affect brain function. Clinical interventions depend on the capacity to understand the equilibrium between beneficial and detrimental gut microbiota, as it affects both neurodegeneration and neuroprotection. The importance of the gut microbiota and its metabolites during brain aging and the development of neurological disorders is summarized in this review. Moreover, we explored the possible therapeutic effects of the gut microbiota on age-related NDDs. Highlighting various pathways that connect the gut and the brain, this review identifies several important domains where gut microbiota-based interventions could offer possible solutions for age-related NDDs. Furthermore, prebiotics and probiotics are discussed as effective alternatives for mitigating indirect causes of gut dysbiosis. These therapeutic interventions are poised to play a significant role in improving dysbiosis and NDDs, paving the way for further research.

Synergistic Effects of Riluzole and Sodium Butyrate on Barrier Function and Disease Progression of Amyotrophic Lateral Sclerosis Through the Gut-Neuron Axis

Emerging evidence has shown that gut-brain barrier dysfunction occurs at the early stages of ALS. Previous studies demonstrated that sodium butyrate significantly prolonged the life span of ALS mice. Riluzole is the first FDA-approved drug for ALS treatment. We hypothesize that Riluzole and sodium butyrate combined treatment further decreases aggregation of the h-SOD1G93A, restores the gut-brain barrier function, and delays ALS progression. SOD1G93A mice (9-10-week-old) were treated with Riluzole (10 mg/kg, I.P. daily), sodium butyrate (2% in drinking water), or Riluzole and sodium butyrate combination for 6 weeks. The Riluzole/butyrate combination showed a significantly longer rotarod time, increased grip strength, and enhanced intestinal barrier, as compared with Riluzole or sodium butyrate-only treatment. More reduction of h-SOD1G93A aggregation was observed in the colon, spinal cord lumbar, and brain cortex with Riluzole and sodium butyrate combination, compared with Riluzole or sodium butyrate-only treatment. Tight junction proteins (ZO-1 and Claudin-5) significantly increased in the colon, spinal cord lumbar, and brain cortex of mice with Riluzole and sodium butyrate treatment. The Riluzole and sodium butyrate combination reduced serum lipopolysaccharides and h-SOD1G93A aggregation, and inflammatory cytokines more than those in Riluzole or sodium butyrate-only treatment. Overall, Riluzole and sodium butyrate treatment is more effective than either Riluzole or sodium butyrate-only in delaying ALS progress. It provides a potential therapeutic strategy and mechanism by restoring barrier function through the gut-brain axis for ALS.

Unveiling amyotrophic lateral sclerosis complexity: insights from proteomics, metabolomics and microbiomics

Amyotrophic lateral sclerosis is the most common motor neuron disease and manifests as a clinically and genetically heterogeneous neurodegenerative disorder mainly affecting the motor systems. To date, despite promising results and accumulating knowledge on the pathomechanisms of amyotrophic lateral sclerosis, a specific disease-modifying treatment is still not available. In vitro and in vivo disease models coupled with multiomics techniques have helped elucidate the pathomechanisms underlying this disease. In particular, omics approaches are powerful tools for identifying new potential disease biomarkers that may be particularly useful for diagnosis, prognosis and assessment of treatment response. In turn, these findings could support physicians in stratifying patients into clinically relevant subgroups for the identification of the best therapeutic targets. Here, we provide a comprehensive review of the most relevant literature highlighting the importance of proteomics approaches in determining the role of pathogenic misfolded/aggregated proteins and the molecular mechanisms involved in the pathogenesis and progression of amyotrophic lateral sclerosis. In addition, we explored new findings arising from metabolomic and lipidomic studies, which can aid to elucidate the intricate metabolic alterations underlying amyotrophic lateral sclerosis pathology. Moreover, we integrated these insights with microbiomics data, providing a thorough understanding of the interplay between metabolic dysregulation and microbial dynamics in disease progression. Indeed, a greater integration of these multiomics data could lead to a deeper understanding of disease mechanisms, supporting the development of specific therapies for amyotrophic lateral sclerosis.

Microbial signatures and therapeutic strategies in neurodegenerative diseases

Neurodegenerative diseases (NDs), including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS), arise from complex interactions between genetic factors, environmental exposures, and aging. Additionally, gut dysbiosis has been linked to systemic inflammation and neurodegeneration. Advances in microbiome and metabolome profiling techniques have provided deeper insights into how alterations in gut microbiota and dietary patterns affect metabolic pathways and contribute to the progression of NDs. This review explores the profiles of gut microbiome and metabolome derived biomarkers and their roles in NDs. Across phyla, families, and genera, we identified 55 microbial alterations in PD, 24 in AD, 4 in ALS, and 17 in MS. Some notable results include an increase in Akkermansia in PD, AD, and MS and a decrease in short-chain fatty acids (SCFAs) in PD and AD. We examined the effects of probiotics, prebiotics, fecal microbiota transplants (FMT), sleep, exercise, and diet on the microbiota, all of which contributed to delayed onset and alleviation of symptoms. Further, artificial intelligence (AI) and machine learning (ML) algorithms applied to omics data have been crucial in identifying novel therapeutic targets, diagnosing and predicting prognosis, and enabling personalized medicine using microbiota-modulating therapies in NDs patients.

Gut Barrier Dysfunction and Microbiota Variations in Cryptosporidiosis: A Comprehensive Review

Cryptosporidiosis is a zoonotic protozoan parasite-born disease, equally significant in both animals and humans, especially affecting immunocompromised individuals (e.g., AIDS patients) and neonates. The prime concerns of this review article are to demonstrate the disruption of the intestinal barrier and variations in the gut microbiome during cryptosporidiosis, and to explore host gut-parasite interactions that can lead to the development of novel therapeutics. The review concluded that the enteric barrier is particularly maintained by tight junction proteins (e.g., occludin, claudin, and ZO-1, etc.) and mucosal immunity, both of which are severely compromised during Cryptosporidium spp. infections, resulting in increased intestinal barrier permeability, inflammatory responses, diarrhea, and ultimately death in severe cases. Cryptosporidium-induced dysbiosis is characterized by reduced microbial diversity and richness, a shift from commensal to pathogenic bacteria, as evidenced by increased pro-inflammatory taxa like Proteobacteria, and reduced proportions of beneficial SCFAs producing bacteria, e.g., Firmicutes. Recent investigations have highlighted the interrelations between gut microbiota and epithelial barrier integrity, especially during cryptosporidiosis, demonstrating the modulations regarding tight junctions (TJs), immune reactions, and SCFA production, all of which are main players in alleviating this protozoal parasitic infection. This review comprehensively describes the fine details underlying these impairments, including autophagy-mediated TJs' degradation, inflammasome activation, and gut microbiome-driven alterations in metabolic pathways, providing the latest relevant, and well-organized piece of knowledge regarding intestinal barrier alterations and microbial shifts during cryptosporidiosis. This work emphasizes the future need for longitudinal studies and advanced sequencing techniques to understand host gut microbiota-parasite interactions, aiming to formulate innovative strategies to mitigate cryptosporidiosis.

Astrocytes phenomics as new druggable targets in healthy aging and Alzheimer's disease progression

For over a century after their discovery astrocytes were regarded merely as cells located among other brain cells to hold and give support to neurons. Astrocytes activation, "astrocytosis" or A1 functional state, was considered a detrimental mechanism against neuronal survival. Recently, the scientific view on astrocytes has changed. Accumulating evidence indicate that astrocytes are not homogeneous, but rather encompass heterogeneous subpopulations of cells that differ from each other in terms of transcriptomics, molecular signature, function and response in physiological and pathological conditions. In this review, we report and discuss the recent literature on the phenomic differences of astrocytes in health and their modifications in disease conditions, focusing mainly on the hippocampus, a region involved in learning and memory encoding, in the age-related memory impairments, and in Alzheimer's disease (AD) dementia. The morphological and functional heterogeneity of astrocytes in different brain regions may be related to their different housekeeping functions. Astrocytes that express diverse transcriptomics and phenomics are present in strictly correlated brain regions and they are likely responsible for interactions essential for the formation of the specialized neural circuits that drive complex behaviors. In the contiguous and interconnected hippocampal areas CA1 and CA3, astrocytes show different, finely regulated, and region-specific heterogeneity. Heterogeneous astrocytes have specific activities in the healthy brain, and respond differently to physiological or pathological stimuli, such as inflammaging present in normal brain aging or beta-amyloid-dependent neuroinflammation typical of AD. To become reactive, astrocytes undergo transcriptional, functional, and morphological changes that transform them into cells with different properties and functions. Alterations of astrocytes affect the neurovascular unit, the blood-brain barrier and reverberate to other brain cell populations, favoring or dysregulating their activities. It will be of great interest to understand whether the differential phenomics of astrocytes in health and disease can explain the diverse vulnerability of the hippocampal areas to aging or to different damaging insults, in order to find new astrocyte-targeted therapies that might prevent or treat neurodegenerative disorders.

Nutritional and Microbiota-Based Approaches in Amyotrophic Lateral Sclerosis: From Prevention to Treatment

Metabolic alterations, including hypermetabolism, lipid imbalances, and glucose dysregulation, are pivotal contributors to the onset and progression of Amyotrophic Lateral Sclerosis (ALS). These changes exacerbate systemic energy deficits, heighten oxidative stress, and fuel neuroinflammation. Simultaneously, gastrointestinal dysfunction and gut microbiota (GM) dysbiosis intensify disease pathology by driving immune dysregulation, compromising the intestinal barrier, and altering gut-brain axis (GBA) signaling, and lastly advancing neurodegeneration. Therapeutic and preventive strategies focused on nutrition offer promising opportunities to address these interconnected pathophysiological mechanisms. Diets enriched with antioxidants, omega-3 fatty acids, and anti-inflammatory compounds-such as the Mediterranean diet-have shown potential in reducing oxidative stress and systemic inflammation. Additionally, microbiota-targeted approaches, including probiotics, prebiotics, postbiotics, and fecal microbiota transplantation, are emerging as innovative tools to restore microbial balance, strengthen gut integrity, and optimize GBA function. This review highlights the critical need for personalized strategies integrating immunonutrition and microbiota modulation to slow ALS progression, improve quality of life, and develop preventive measures for neurodegenerative and neuroinflammatory diseases. Future research should prioritize comprehensive dietary and microbiota-based interventions to uncover their therapeutic potential and establish evidence-based guidelines for managing ALS and related disorders.

Inhibiting NF-κB inducing kinase improved the motor performance of ALS animal model

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a typical neurodegenerative disorder typically characterized by inflammation activation. However, the relationship between non-canonical NF-κB (ncNF-κB) pathway activation and ALS progression is not clear.

METHODS

We tested the ncNF-κB pathway in the ALS animal model including hSOD1-G93A transgenic mice and TBK1 deletion mice.We treated age-matched SOD1-G93A mice with B022 (a NIK inhibitor) to investigate the role of NIK in the ALS animal model. We also established a new mice model by crossing SOD1-G93A mice with NIK+/- mice to further evaluate the interrelationship between the NIK and the disease progression in ALS animal model.

RESULTS

In this study, we found the ncNF-κB pathway was activated in SOD1-G93A animal model and TBK1 deletion model. Inhibition of NIK activity by small molecule B022 significantly improved the motor performance of the ALS animal model. However, NIK deletion enhanced the mutant SOD1 toxicity by inflammatory infiltration.

CONCLUSION

TBK1 deletion and mutant SOD1 shared the common pathological feature possibly via effects on NIK activation and inhibitor of NIK could be a novel strategy for treating ALS.

Ageing, proteostasis, and the gut: Insights into neurological health and disease

Recent research has illuminated the profound bidirectional communication between the gastrointestinal tract and the brain, furthering our understanding of neurological ailments facilitating possible therapeutic strategies. Technological advancements in high-throughput sequencing and multi-omics have unveiled significant alterations in gut microbiota and their metabolites in various neurological disorders. This review provides a thorough analysis of the role of microbiome-gut-brain axis in neurodegenerative disease pathology, linking it to reduced age-associated proteostasis. We discuss evidences that substantiate the existence of a gut-brain cross talk ranging from early clinical accounts of James Parkinson to Braak's hypothesis. In addition to understanding of microbes, the review particularly entails specific metabolites which are altered in neurodegenerative diseases. The regulatory effects of microbial metabolites on protein clearance mechanisms, proposing their potential therapeutic implications, are also discussed. By integrating this information, we advocate for a combinatory therapeutic strategy that targets early intervention, aiming to restore proteostasis and ameliorate disease progression. This approach not only provides a new perspective on the pathogenesis of neurodegenerative diseases but also highlights innovative strategies to combat the increasing burden of these age-related disorders.

Examining the complex Interplay between gut microbiota abundance and short-chain fatty acid production in amyotrophic lateral sclerosis patients shortly after onset of disease

This study aimed to assess differences in the enteral microbiome of relatively recent-onset amyotrophic lateral sclerosis (ALS) patients (< 6-15 months since symptom onset) compared to healthy individuals, focusing on short-chain fatty acids (SCFAs) as potential mediators of host metabolism. We included 28 volunteers (16 ALS, 12 controls) with informed consent. No significant effect of ALS on alpha diversity (measuring the variety and abundance of species within a single sample, and indicating the health and complexity of the microbiome) was observed, but ALS patients had higher abundances of Fusobacteria and Acidobacteria. ALS subtypes influenced specific species, with increased Fusobacteria and Tenericutes in spinal ALS compared to bulbar ALS. ALS patients showed increased Enterobacter, Clostridium, Veillonella, Dialister, Turicibacter, and Acidaminococcus species and decreased Prevotella, Lactobacillus, and Butyricimonas. Correlations between species varied between ALS patients and healthy individuals and among ALS subtypes. No significant differences in SCFA concentrations were found, but spinal ALS samples showed a trend towards decreased propionate content. Relationships between SCFAs and phyla colonization differed by disease status. This study suggests distinct enteral microbiome characteristics in ALS patients, though the implications are unclear. Further research is needed to determine if these differences are causative or consequential and to explore their potential as diagnostic or therapeutic targets. The study also underscores the heterogeneity of microbiome constraints in ALS and the need for more research into ALS and SCFA metabolism.

The Microbiota-Gut-Brain Axis and Neurological Disorders: A Comprehensive Review

Microbes have inhabited the earth for hundreds of millions of years longer than humans. The microbiota-gut-brain axis (MGBA) represents a bidirectional communication pathway. These communications occur between the central nervous system (CNS), the enteric nervous system (ENS), and the emotional and cognitive centres of the brain. The field of research on the gut-brain axis has grown significantly during the past two decades. Signalling occurs between the gut microbiota and the brain through the neural, endocrine, immune, and humoral pathways. A substantial body of evidence indicates that the MGBA plays a pivotal role in various neurological diseases. These include Alzheimer's disease (AD), autism spectrum disorder (ASD), Rett syndrome, attention deficit hyperactivity disorder (ADHD), non-Alzheimer's neurodegeneration and dementias, fronto-temporal lobe dementia (FTLD), Wilson-Konovalov disease (WD), multisystem atrophy (MSA), Huntington's chorea (HC), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), temporal lobe epilepsy (TLE), depression, and schizophrenia (SCZ). Furthermore, the bidirectional correlation between therapeutics and the gut-brain axis will be discussed. Conversely, the mood of delivery, exercise, psychotropic agents, stress, and neurologic drugs can influence the MGBA. By understanding the MGBA, it may be possible to facilitate research into microbial-based interventions and therapeutic strategies for neurological diseases.

Psychobiotic Properties of Lactiplantibacillus plantarum in Neurodegenerative Diseases

Neurodegenerative disorders are the main cause of cognitive and physical disabilities, affect millions of people worldwide, and their incidence is on the rise. Emerging evidence pinpoints a disturbance of the communication of the gut-brain axis, and in particular to gut microbial dysbiosis, as one of the contributors to the pathogenesis of these diseases. In fact, dysbiosis has been associated with neuro-inflammatory processes, hyperactivation of the neuronal immune system, impaired cognitive functions, aging, depression, sleeping disorders, and anxiety. With the rapid advance in metagenomics, metabolomics, and big data analysis, together with a multidisciplinary approach, a new horizon has just emerged in the fields of translational neurodegenerative disease. In fact, recent studies focusing on taxonomic profiling and leaky gut in the pathogenesis of neurodegenerative disorders are not only shedding light on an overlooked field but are also creating opportunities for biomarker discovery and development of new therapeutic and adjuvant strategies to treat these disorders. Lactiplantibacillus plantarum (LBP) strains are emerging as promising psychobiotics for the treatment of these diseases. In fact, LBP strains are able to promote eubiosis, increase the enrichment of bacteria producing beneficial metabolites such as short-chain fatty acids, boost the production of neurotransmitters, and support the homeostasis of the gut-brain axis. In this review, we summarize the current knowledge on the role of the gut microbiota in the pathogenesis of neurodegenerative disorders with a particular focus on the benefits of LBP strains in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, autism, anxiety, and depression.

Brain-body mechanisms contribute to sexual dimorphism in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common form of human motor neuron disease. It is characterized by the progressive degeneration of upper and lower motor neurons, leading to generalized motor weakness and, ultimately, respiratory paralysis and death within 3-5 years. The disease is shaped by genetics, age, sex and environmental stressors, but no cure or routine biomarkers exist for the disease. Male individuals have a higher propensity to develop ALS, and a different manifestation of the disease phenotype, than female individuals. However, the mechanisms underlying these sex differences remain a mystery. In this Review, we summarize the epidemiology of ALS, examine the sexually dimorphic presentation of the disease and highlight the genetic variants and molecular pathways that might contribute to sex differences in humans and animal models of ALS. We advance the idea that sexual dimorphism in ALS arises from the interactions between the CNS and peripheral organs, involving vascular, metabolic, endocrine, musculoskeletal and immune systems, which are strikingly different between male and female individuals. Finally, we review the response to treatments in ALS and discuss the potential to implement future personalized therapeutic strategies for the disease.

Contribution of CNS and extra-CNS infections to neurodegeneration: a narrative review

Central nervous system infections have been suggested as a possible cause for neurodegenerative diseases, particularly sporadic cases. They trigger neuroinflammation which is considered integrally involved in neurodegenerative processes. In this review, we will look at data linking a variety of viral, bacterial, fungal, and protozoan infections to Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis and unspecified dementia. This narrative review aims to bring together a broad range of data currently supporting the involvement of central nervous system infections in the development of neurodegenerative diseases. The idea that no single pathogen or pathogen group is responsible for neurodegenerative diseases will be discussed. Instead, we suggest that a wide range of susceptibility factors may make individuals differentially vulnerable to different infectious pathogens and subsequent pathologies.

Butyrate as a potential therapeutic agent for neurodegenerative disorders

Maintaining an optimum microbial community within the gastrointestinal tract is intricately linked to human metabolic, immune and brain health. Disturbance to these microbial populations perturbs the production of vital bioactive compounds synthesised by the gut microbiome, such as short-chain fatty acids (SCFAs). Of the SCFAs, butyrate is known to be a major source of energy for colonocytes and has valuable effects on the maintenance of intestinal epithelium and blood brain barrier integrity, gut motility and transit, anti-inflammatory effects, and autophagy induction. Inducing endogenous butyrate production is likely to be beneficial for gut-brain homeostasis and for optimal neuronal function. For these reasons, butyrate has gained interest as a potential therapy for not only metabolic and immunological disorders, but also conditions related to the brain, including neurodegenerative diseases. While direct and indirect sources of butyrate, including prebiotics, probiotics, butyrate pro-drugs and glucosidase inhibitors, offer a promising therapeutic avenue, their efficacy and dosage in neurodegenerative conditions remain largely unknown. Here, we review current literature on effects of butyrate relevant to neuronal function, the impact of butyrate in a range of neurodegenerative diseases and related treatments that may have potential for the treatment of neurodegenerative diseases.

Bridging the Gap: Harnessing Plant Bioactive Molecules to Target Gut Microbiome Dysfunctions in Amyotrophic Lateral Sclerosis

The correlation between neurodegenerative diseases and the gut microbiome is increasingly evident, with amyotrophic lateral sclerosis (ALS) being particularly notable for its severity and lack of therapeutic options. The gut microbiota, implicated in the pathogenesis and development of ALS, plays a crucial role in the disease. Bioactive plant molecules, specifically volatile compounds in essential oils, offer a promising therapeutic avenue due to their anti-inflammatory properties and gut-modulating effects. Our narrative review aimed to identify microbiota-associated bacteria in ALS and analyze the benefits of administering bioactive plant molecules as much-needed therapeutic options in the management of this disease. A comprehensive search of PubMed database articles published before December 2023, encompassing research on cell, human, and animal ALS models, was conducted. After selecting, analyzing, and discussing key articles, bacteria linked to ALS pathogenesis and physiopathology were identified. Notably, positively highlighted bacteria included Akkermansia muciniphila (Verrucomicrobia phylum), Faecalibacterium prausnitzii, and Butyrivibrio spp. (Firmicutes phylum). Conversely, members of the Escherichia coli spp. (Proteobacteria phylum) and Ruminococcus spp. (Firmicutes phylum) stood out negatively in respect to ALS development. These bacteria were associated with molecular changes linked to ALS pathogenesis and evolution. Bioactive plant molecules can be directly associated with improvements in the microbiome, due to their role in reducing inflammation and oxidative stress, emerging as one of the most promising natural agents for enriching present-day ALS treatments.

Is gut microbiota of patients with ALS different from that of healthy individuals?

Background/aim

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. Several studies have shown that alterations of microbiota increase the risk of neurodegenerative disorders. We aimed to reveal whether there is a difference in the gut microbiota of patients with ALS.

Materials and methods

The participants are divided into three groups. Group 1 comprised patients with ALS. Healthy family members living in the same house of the patients formed Group 2. Lastly, sex- and age-matched healthy people were included in Group 3. Fecal samples were collected in 15-mL falcon tubes and stored at -80 °C. Genomic DNA isolation was performed on samples. Bacterial primers selected from the 16S rRNA region for the bacterial genome and ITS1 and ITS4 (internal transcribed spacer) were used for the identification of DNA. Next generation sequence analysis (NGS) and taxonomic analyses were performed at the level of bacterial phylum, class, order, family, genus, and species. Alpha and beta diversity indexes were used. The linear discriminant analysis (LDA) effect size method (LEfSe) was applied to identify a microbial taxon specific to ALS disease.

Results

The relative abundances of the Succinivibrionaceae and Lachnospiraceae families were significantly lower in patients. The dominant families among patients were Streptococcaceae and Ruminococcaceae, while the dominant families among healthy controls were Bacteroidaceae and Succinivibrionaceae. The LEfSe analysis revealed that four families (Atopobiaceae, Actinomycetaceae, Erysipelatoclostridiaceae, Peptococcacceae) differed significantly between the patients and healthy controls (LDA values> 2.5, p < 0.05).

Conclusion

Comparison with family members living in the same house is the strength of this study. We found that there were changes in the microbiota of the patients, consistent with the literature. Studies that analyze the composition of the gut microbiota in the predisease period may be needed to understand whether dysbiosis is caused by the mechanisms inherent in the disease or whether it is dysbiosis that initiates the disease.

Toxic effects of combined exposure to cadmium and diclofenac on freshwater crayfish (Procambarus clarkii): Insights from antioxidant enzyme activity, histopathology, and gut microbiome

In recent years, excessive discharge of pollutants has led to increasing concentrations of cadmium (Cd) and diclofenac (DCF) in water; however, the toxicity mechanism of combined exposure of the two pollutants to aquatic animals has not been fully studied. Procambarus clarkii is an economically important aquatic species that is easily affected by Cd and DCF. This study examined the effects of combined exposure to Cd and DCF on the tissue accumulation, physiology, biochemistry, and gut microflora of P. clarkii. The results showed that Cd and DCF accumulated in tissues in the order of hepatopancreas > gill > intestine > muscle. The hepatopancreas and intestines were subjected to severe oxidative stress, with significantly increased antioxidant enzyme activity. Pathological examination revealed lumen expansion and epithelial vacuolisation in the hepatopancreas and damage to the villous capillaries and wall in the intestine. The co-exposure to Cadmium (Cd) and Diclofenac (DCF) disrupts the Firmicutes/Bacteroidetes (F/B) ratio, impairing the regular functioning of intestinal microbiota in carbon (C) and nitrogen (N) cycling. This disturbance consequently hinders the absorption and utilization of energy and nutrients in Procambarus clarkii. This study offers critical insights into the toxicological mechanisms underlying the combined effects of Cd and DCF, and suggests potential approaches to alleviate their adverse impacts on aquatic ecosystems.

Gut-Modulating Agents and Amyotrophic Lateral Sclerosis: Current Evidence and Future Perspectives

Amyotrophic Lateral Sclerosis (ALS) is a highly fatal neurodegenerative disorder characterized by the progressive wasting and paralysis of voluntary muscle. Despite extensive research, the etiology of ALS remains elusive, and effective treatment options are limited. However, recent evidence implicates gut dysbiosis and gut-brain axis (GBA) dysfunction in ALS pathogenesis. Alterations to the composition and diversity of microbial communities within the gut flora have been consistently observed in ALS patients. These changes are often correlated with disease progression and patient outcome, suggesting that GBA modulation may have therapeutic potential. Indeed, targeting the gut microbiota has been shown to be neuroprotective in several animal models, alleviating motor symptoms and mitigating disease progression. However, the translation of these findings to human patients is challenging due to the complexity of ALS pathology and the varying diversity of gut microbiota. This review comprehensively summarizes the current literature on ALS-related gut dysbiosis, focusing on the implications of GBA dysfunction. It delineates three main mechanisms by which dysbiosis contributes to ALS pathology: compromised intestinal barrier integrity, metabolic dysfunction, and immune dysregulation. It also examines preclinical evidence on the therapeutic potential of gut-microbiota-modulating agents (categorized as prebiotics, probiotics, and postbiotics) in ALS.

Fecal microbiota transplantation unveils sex-specific differences in a controlled cortical impact injury mouse model

Introduction

Contusion type of traumatic brain injury (TBI) is a major cause of locomotor disability and mortality worldwide. While post-TBI deleterious consequences are influenced by gender and gut dysbiosis, the sex-specific importance of commensal gut microbiota is underexplored after TBI. In this study, we investigated the impact of controlled cortical impact (CCI) injury on gut microbiota signature in a sex-specific manner in mice.

Methods

We depleted the gut microflora of male and female C57BL/6 mice using antibiotic treatment. Thereafter, male mice were colonized by the gut microbiota of female mice and vice versa, employing the fecal microbiota transplantation (FMT) method. CCI surgery was executed using a stereotaxic impactor (Impact One™). For the 16S rRNA gene amplicon study, fecal boli of mice were collected at 3 days post-CCI (dpi).

Results and discussion

CCI-operated male and female mice exhibited a significant alteration in the genera of Akkermansia, Alistipes, Bacteroides, Clostridium, Lactobacillus, Prevotella, and Ruminococcus. At the species level, less abundance of Lactobacillus helveticus and Lactobacillus hamsteri was observed in female mice, implicating the importance of sex-specific bacteriotherapy in CCI-induced neurological deficits. FMT from female donor mice to male mice displayed an increase in genera of Alistipes, Lactobacillus, and Ruminococcus and species of Bacteroides acidifaciens and Ruminococcus gnavus. Female FMT-recipient mice from male donors showed an upsurge in the genus Lactobacillus and species of Lactobacillus helveticus, Lactobacillus hamsteri, and Prevotella copri. These results suggest that the post-CCI neurological complications may be influenced by the differential gut microbiota perturbation in male and female mice.

Gut Symptoms, Gut Dysbiosis and Gut-Derived Toxins in ALS

Many pathogenetic mechanisms have been proposed for amyotrophic lateral sclerosis (ALS). Recently, there have been emerging suggestions of a possible role for the gut microbiota. Gut microbiota have a range of functions and could influence ALS by several mechanisms. Here, we review the possible role of gut-derived neurotoxins/excitotoxins. We review the evidence of gut symptoms and gut dysbiosis in ALS. We then examine a possible role for gut-derived toxins by reviewing the evidence that these molecules are toxic to the central nervous system, evidence of their association with ALS, the existence of biochemical pathways by which these molecules could be produced by the gut microbiota and existence of mechanisms of transport from the gut to the blood and brain. We then present evidence that there are increased levels of these toxins in the blood of some ALS patients. We review the effects of therapies that attempt to alter the gut microbiota or ameliorate the biochemical effects of gut toxins. It is possible that gut dysbiosis contributes to elevated levels of toxins and that these could potentially contribute to ALS pathogenesis, but more work is required.

Brain-Gut-Microbiota Axis in Amyotrophic Lateral Sclerosis: A Historical Overview and Future Directions

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disease which is strongly associated with age. The incidence of ALS increases from the age of 40 and peaks between the ages of 65 and 70. Most patients die of respiratory muscle paralysis or lung infections within three to five years of the appearance of symptoms, dealing a huge blow to patients and their families. With aging populations, improved diagnostic methods and changes in reporting criteria, the incidence of ALS is likely to show an upward trend in the coming decades. Despite extensive researches have been done, the cause and pathogenesis of ALS remains unclear. In recent decades, large quantities of studies focusing on gut microbiota have shown that gut microbiota and its metabolites seem to change the evolvement of ALS through the brain-gut-microbiota axis, and in turn, the progression of ALS will exacerbate the imbalance of gut microbiota, thereby forming a vicious cycle. This suggests that further exploration and identification of the function of gut microbiota in ALS may be crucial to break the bottleneck in the diagnosis and treatment of this disease. Hence, the current review summarizes and discusses the latest research advancement and future directions of ALS and brain-gut-microbiota axis, so as to help relevant researchers gain correlative information instantly.

Nutritional, Clinical and Sociodemographic Profiles of Spanish Patients with Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a chronic and progressive neurodegenerative disease that leads to the loss of motor neurons. The dietary intake of ALS patients is thought to influence the prognosis and progression of the disease. The aim of this study was to examine the nutritional, clinical and sociodemographic characteristics of ALS patients in Spain. A cross-sectional descriptive study with demographics, clinical anamnesis and anthropometric assessment was carried out. Nutritional intake was recorded and compared with dietary reference intakes (DRI). Forty subjects (25 males; 15 females) aged 54.7 ± 10.17 were included in the study. The mean weight and height were 67.99 ± 8.85 kg and 167.83 ± 8.79 cm, respectively. Clinical phenotype, time to diagnosis, year of onset and family history were not associated with the place of origin. Clinical phenotype had no influence on time of diagnosis. Caloric and protein intakes were adequate, while carbohydrate, vitamin B8 and iodine intakes were significantly lower than the DRI. Lipids; vitamins B1, B2, B3, B5, B6, B12, C and E; sodium; phosphorus; and selenium intakes were significantly higher than the recommended nutritional standards. ALS patients, who are homogeneously distributed throughout our national territory, should modify their dietary habits to minimize ultra-processed products and prioritize foods rich in healthy fats and fiber.

Impaired communication at the neuromotor axis during Degenerative Cervical Myelopathy

Degenerative Cervical Myelopathy (DCM) is a progressive neurological condition characterized by structural alterations in the cervical spine, resulting in compression of the spinal cord. While clinical manifestations of DCM are well-documented, numerous unanswered questions persist at the molecular and cellular levels. In this study, we sought to investigate the neuromotor axis during DCM. We use a clinically relevant mouse model, where after 3 months of DCM induction, the sensorimotor tests revealed a significant reduction in both locomotor activity and muscle strength compared to the control group. Immunohistochemical analyses showed alterations in the gross anatomy of the cervical spinal cord segment after DCM. These changes were concomitant with the loss of motoneurons and a decrease in the number of excitatory synaptic inputs within the spinal cord. Additionally, the DCM group exhibited a reduction in the endplate surface, which correlated with diminished presynaptic axon endings in the supraspinous muscles. Furthermore, the biceps brachii (BB) muscle exhibited signs of atrophy and impaired regenerative capacity, which inversely correlated with the transversal area of remnants of muscle fibers. Additionally, metabolic assessments in BB muscle indicated an increased proportion of oxidative skeletal muscle fibers. In line with the link between neuromotor disorders and gut alterations, DCM mice displayed smaller mucin granules in the mucosa layer without damage to the epithelial barrier in the colon. Notably, a shift in the abundance of microbiota phylum profiles reveals an elevated Firmicutes-to-Bacteroidetes ratio-a consistent hallmark of dysbiosis that correlates with alterations in gut microbiota-derived metabolites. Additionally, treatment with short-chain fatty acids stimulated the differentiation of the motoneuron-like NSC34 cell line. These findings shed light on the multifaceted nature of DCM, resembling a synaptopathy that disrupts cellular communication within the neuromotor axis while concurrently exerting influence on other systems. Notably, the colon emerges as a focal point, experiencing substantial perturbations in both mucosal barrier integrity and the delicate balance of intestinal microbiota.

More than just a number: the gut microbiota and brain function across the extremes of life

Understanding the interrelationship between the gut microbiota and host physiology, although still in its relative infancy, has taken important steps forward over the past decade. In the context of brain disorders including those characterized by neurodevelopmental and neurodegenerative changes there have been important advances. However, initially research involved correlational analyses, had limited translational scope, and lacked functional assessments. Thus, largescale longitudinal clinical investigations that assess causation and underlying mechanisms via in depth analysis methods are needed. In neurodegeneration research, strong causal evidence now links the gut microbiome to Alzheimer's (AD), and Parkinson's Disease (PD), as supported by human-to-animal transplantation studies. Longitudinal interventions are being conducted in AD, PD, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis. Neurodevelopmental research has also seen a boon in microbiome-related clinical research including in autism, Attention-deficit/hyperactivity disorder, and schizophrenia, which is confirming prior animal model work regarding the key time-windows in the gut microbiome important for infant cognition. While recent research advances represent important progress, fundamental knowledge gaps and obstacles remain. Knowing how and why the gut microbiome changes at the extremes of life will develop our mechanistic understanding and help build the evidence base as we strive toward counteracting microbial missteps with precision therapeutic interventions.

Reverse engineering the Gut-Brain Axis and microbiome-metabolomics for symbiotic/pathogenic balance in neurodegenerative diseases

Deciphering the molecular communications along the gut-brain axis can help in understanding the pathophysiology of neurodegenerative diseases and exploiting the gut microbiome for therapeutics. However, gut microbes and their metabolites have a multifaceted role in mediating both brain physiology and neurodegenerative pathology. There is a lack of understanding of how and when this role is tipped in neurodegenerative diseases and what are those contributing factors, both at local (gut) and distal (neuronal) levels, that drive this imbalance. Here we have reviewed the gut microbiome and its metabolites in the context of the gut-brain axis and summarized how different factors such as gut-microbial diversity, their metabolites, the role of the native immune system and the integrity of gut epithelial and blood-brain barriers are interconnected and collectively define the involvement of gut-microbiome in neurodegenerative pathologies. It also underlines the need for multidisciplinary tools and animal models to simultaneously reflect on many of these factors and to better correlate with clinical observations and data obtained from human biopsies and fecal samples. Harnessing the gut-brain axis will herald a paradigm shift in medicine for neurodegenerative diseases and aging, emphasizing the significance of the microbiome in the broader spectrum of health and disease.

Gut-Brain Axis Deregulation and Its Possible Contribution to Neurodegenerative Disorders

The gut-brain axis is an essential communication pathway between the central nervous system (CNS) and the gastrointestinal tract. The human microbiota is composed of a diverse and abundant microbial community that compasses more than 100 trillion microorganisms that participate in relevant physiological functions such as host nutrient metabolism, structural integrity, maintenance of the gut mucosal barrier, and immunomodulation. Recent evidence in animal models has been instrumental in demonstrating the possible role of the microbiota in neurodevelopment, neuroinflammation, and behavior. Furthermore, clinical studies suggested that adverse changes in the microbiota can be considered a susceptibility factor for neurological disorders (NDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). In this review, we will discuss evidence describing the role of gut microbes in health and disease as a relevant risk factor in the pathogenesis of neurodegenerative disorders, including AD, PD, HD, and ALS.

Predicting foodborne pathogens and probiotics taxa within poultry-related microbiomes using a machine learning approach

BACKGROUND

Microbiomes that can serve as an indicator of gut, intestinal, and general health of humans and animals are largely influenced by food consumed and contaminant bioagents. Microbiome studies usually focus on estimating the alpha (within sample) and beta (similarity/dissimilarity among samples) diversities. This study took a combinatorial approach and applied machine learning to microbiome data to predict the presence of disease-causing pathogens and their association with known/potential probiotic taxa. Probiotics are beneficial living microorganisms capable of improving the host organism's digestive system, immune function and ultimately overall health. Here, 16 S rRNA gene high-throughput Illumina sequencing of temporal pre-harvest (feces, soil) samples of 42 pastured poultry flocks (poultry in this entire work solely refers to chickens) from southeastern U.S. farms was used to generate the relative abundance of operational taxonomic units (OTUs) as machine learning input. Unique genera from the OTUs were used as predictors of the prevalence of foodborne pathogens (Salmonella, Campylobacter and Listeria) at different stages of poultry growth (START (2-4 weeks old), MID (5-7 weeks old), END (8-11 weeks old)), association with farm management practices and physicochemical properties.

RESULT

While we did not see any significant associations between known probiotics and Salmonella or Listeria, we observed significant negative correlations between known probiotics (Bacillus and Clostridium) and Campylobacter at the mid-time point of sample collection. Our data indicates a negative correlation between potential probiotics and Campylobacter at both early and end-time points of sample collection. Furthermore, our model prediction shows that changes in farm operations such as how often the houses are moved on the pasture, age at which chickens are introduced to the pasture, diet composition and presence of other animals on the farm could favorably increase the abundance and activity of probiotics that could reduce Campylobacter prevalence.

CONCLUSION

Integration of microbiome data with farm management practices using machine learning provided insights on how to reduce Campylobacter prevalence and transmission along the farm-to-fork continuum. Altering management practices to support proliferation of beneficial probiotics to reduce pathogen prevalence identified here could constitute a complementary method to the existing but ineffective interventions such as vaccination and bacteriophage cocktails usage. Study findings also corroborate the presence of bacterial genera such as Caloramator, DA101, Parabacteroides and Faecalibacterium as potential probiotics.

Causal Associations between Gut Microbiota and Different Types of Dyslipidemia: A Two-Sample Mendelian Randomization Study

The determination of a causal association between gut microbiota and a range of dyslipidemia remains uncertain. To clarify these associations, we employed a two-sample Mendelian randomization (MR) analysis utilizing the inverse-variance weighted (IVW) method. This comprehensive analysis investigated the genetic variants that exhibited a significant association (p < 5 × 10-8) with 129 distinct gut microbiota genera and their potential link to different types of dyslipidemia. The results indicated a potential causal association between 22 gut microbiota genera and dyslipidemia in humans. Furthermore, these findings suggested that the impact of gut microbiota on dyslipidemia regulation is dependent on the specific phylum, family, and genus. Bacillota phylum demonstrated the greatest diversity, with 15 distinct genera distributed among eight families. Notably, gut microbiota-derived from the Lachnospiraceae and Lactobacillaceae families exhibit statistically significant associations with lipid levels that contribute to overall health (p < 0.05). The sensitivity analysis indicated that our findings possess robustness (p > 0.05). The findings of our investigation provide compelling evidence that substantiates a causal association between the gut microbiota and dyslipidemia in the human body. It is noteworthy to highlight the significant influence of the Bacillota phylum as a crucial regulator of lipid levels, and the families Lachnospiraceae and Lactobacillaceae should be recognized as probiotics that significantly contribute to this metabolic process.

The Role of Short-Chain Fatty Acids in Microbiota-Gut-Brain Cross-Talk with a Focus on Amyotrophic Lateral Sclerosis: A Systematic Review

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease characterized by the gradual loss of motor neurons in the brain and spinal cord, leading to progressive motor function decline. Unfortunately, there is no effective treatment, and its increasing prevalence is linked to an aging population, improved diagnostics, heightened awareness, and changing lifestyles. In the gastrointestinal system, the gut microbiota plays a vital role in producing metabolites, neurotransmitters, and immune molecules. Short-chain fatty acids, of interest for their potential health benefits, are influenced by a fiber- and plant-based diet, promoting a diverse and balanced gut microbiome. These fatty acids impact the body by binding to receptors on enteroendocrine cells, influencing hormones like glucagon-like peptide-1 and peptide YY, which regulate appetite and insulin sensitivity. Furthermore, these fatty acids impact the blood-brain barrier, neurotransmitter levels, and neurotrophic factors, and directly stimulate vagal afferent nerves, affecting gut-brain communication. The vagus nerve is a crucial link between the gut and the brain, transmitting signals related to appetite, inflammation, and various processes. Dysregulation of this pathway can contribute to conditions like obesity and irritable bowel syndrome. Emerging evidence suggests the complex interplay among these fatty acids, the gut microbiota, and environmental factors influences neurodegenerative processes via interconnected pathways, including immune function, anti-inflammation, gut barrier, and energy metabolism. Embracing a balanced, fiber-rich diet may foster a diverse gut microbiome, potentially impacting neurodegenerative disease risk. Comprehensive understanding requires further research into interventions targeting the gut microbiome and fatty acid production and their potential therapeutic role in neurodegeneration.

Gut microbiota in muscular atrophy development, progression, and treatment: New therapeutic targets and opportunities

Skeletal muscle atrophy is a debilitating condition that significantly affects quality of life and often lacks effective treatment options. Muscle atrophy can have various causes, including myogenic, neurogenic, and other factors. Recent investigation has underscored a compelling link between the gut microbiota and skeletal muscle. Discerning the potential differences in the gut microbiota associated with muscle atrophy-related diseases, understanding their influence on disease development, and recognizing their potential as intervention targets are of paramount importance. This review aims to provide a comprehensive overview of the role of the gut microbiota in muscle atrophy-related diseases. We summarize clinical and pre-clinical studies that investigate the potential for gut microbiota modulation to enhance muscle performance and promote disease recovery. Furthermore, we delve into the intricate interplay between the gut microbiota and muscle atrophy-related diseases, drawing from an array of studies. Emerging evidence suggests significant differences in gut microbiota composition in individuals with muscle atrophy-related diseases compared with healthy individuals. It is conceivable that these alterations in the microbiota contribute to the pathogenesis of these disorders through bacterium-related metabolites or inflammatory signals. Additionally, interventions targeting the gut microbiota have demonstrated promising results for mitigating disease progression in animal models, underscoring the therapeutic potential of modulating the gut microbiota in these conditions. By analyzing the available literature, this review sheds light on the involvement of the gut microbiota in muscle atrophy-related diseases. The findings contribute to our understanding of the underlying mechanisms and open avenues for development of novel therapeutic strategies targeting the gut-muscle axis.

Gut Microbial Metabolome and Dysbiosis in Neurodegenerative Diseases: Psychobiotics and Fecal Microbiota Transplantation as a Therapeutic Approach-A Comprehensive Narrative Review

The comprehensive narrative review conducted in this study delves into the mechanisms of communication and action at the molecular level in the human organism. The review addresses the complex mechanism involved in the microbiota-gut-brain axis as well as the implications of alterations in the microbial composition of patients with neurodegenerative diseases. The pathophysiology of neurodegenerative diseases with neuronal loss or death is analyzed, as well as the mechanisms of action of the main metabolites involved in the bidirectional communication through the microbiota-gut-brain axis. In addition, interventions targeting gut microbiota restructuring through fecal microbiota transplantation and the use of psychobiotics-pre- and pro-biotics-are evaluated as an opportunity to reduce the symptomatology associated with neurodegeneration in these pathologies. This review provides valuable information and facilitates a better understanding of the neurobiological mechanisms to be addressed in the treatment of neurodegenerative diseases.

Probiotics for Neurodegenerative Diseases: A Systemic Review

Neurodegenerative disorders (ND) are a group of conditions that affect the neurons in the brain and spinal cord, leading to their degeneration and eventually causing the loss of function in the affected areas. These disorders can be caused by a range of factors, including genetics, environmental factors, and lifestyle choices. Major pathological signs of these diseases are protein misfolding, proteosomal dysfunction, aggregation, inadequate degradation, oxidative stress, free radical formation, mitochondrial dysfunctions, impaired bioenergetics, DNA damage, fragmentation of Golgi apparatus neurons, disruption of axonal transport, dysfunction of neurotrophins (NTFs), neuroinflammatory or neuroimmune processes, and neurohumoral symptoms. According to recent studies, defects or imbalances in gut microbiota can directly lead to neurological disorders through the gut-brain axis. Probiotics in ND are recommended to prevent cognitive dysfunction, which is a major symptom of these diseases. Many in vivo and clinical trials have revealed that probiotics (Lactobacillus acidophilus, Bifidobacterium bifidum, and Lactobacillus casei, etc.) are effective candidates against the progression of ND. It has been proven that the inflammatory process and oxidative stress can be modulated by modifying the gut microbiota with the help of probiotics. As a result, this study provides an overview of the available data, bacterial variety, gut-brain axis defects, and probiotics' mode of action in averting ND. A literature search on particular sites, including PubMed, Nature, and Springer Link, has identified articles that might be pertinent to this subject. The search contains the following few groups of terms: (1) Neurodegenerative disorders and Probiotics OR (2) Probiotics and Neurodegenerative disorders. The outcomes of this study aid in elucidating the relationship between the effects of probiotics on different neurodegenerative disorders. This systematic review will assist in discovering new treatments in the future, as probiotics are generally safe and cause mild side effects in some cases in the human body.

Mutant and curli-producing E. coli enhance the disease phenotype in a hSOD1-G93A mouse model of ALS

The gut microbiome is a potential non-genetic contributing factor for Amyotrophic Lateral Sclerosis. Differences in gut microbial communities have been detected between ALS subjects and healthy controls, including an increase in Escherichia coli in ALS subjects. E. coli and other gram-negative bacteria produce curli proteins, which are functional bacterial amyloids. We examined whether long-term curli overexposure in the gut can exacerbate the development and progression of ALS. We utilized the slow-developing hSOD1-G93A mouse model of ALS with their C57BL/6J WT littermate controls, including males and females, with a total of 91 animals. These mice were on a normal chow diet and fed curli-producing or curli-nonproducing (mutant) E. coli in applesauce (vehicle) 3 times/week, from 1 through 7 months of age. Male hSOD1 mice demonstrated gradual slowing in running speed month 4 onwards, while females exhibited no signs of locomotive impairment even at 7 months of age. Around the same time, male hSOD1 mice showed a gradual increase in frequency of peripheral CD19⁺ B cells. Among the male hSOD1 group, chronic gut exposure to curli-producing E. coli led to significant shifts in α- and β-diversities. Curli-exposed males showed suppression of immune responses in circulation, but an increase in markers of inflammation, autophagy and protein turnover in skeletal muscle. Some of these markers were also changed in mutant E. coli-exposed mice, including astrogliosis in the brainstem and demyelination in the lumbar spinal cord. Overall, chronic overexposure to a commensal bacteria like E. coli led to distant organ pathology in our model, without the presence of a leaky gut at 6 months. Mechanisms underlying gut-distant organ communication are of tremendous interest to all disciplines.

What the Gut Tells the Brain-Is There a Link between Microbiota and Huntington's Disease?

The human intestinal microbiota is a diverse and dynamic microenvironment that forms a complex, bi-directional relationship with the host. The microbiome takes part in the digestion of food and the generation of crucial nutrients such as short chain fatty acids (SCFA), but is also impacts the host's metabolism, immune system, and even brain functions. Due to its indispensable role, microbiota has been implicated in both the maintenance of health and the pathogenesis of many diseases. Dysbiosis in the gut microbiota has already been implicated in many neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD). However, not much is known about the microbiome composition and its interactions in Huntington's disease (HD). This dominantly heritable, incurable neurodegenerative disease is caused by the expansion of CAG trinucleotide repeats in the huntingtin gene (HTT). As a result, toxic RNA and mutant protein (mHTT), rich in polyglutamine (polyQ), accumulate particularly in the brain, leading to its impaired functions. Interestingly, recent studies indicated that mHTT is also widely expressed in the intestines and could possibly interact with the microbiota, affecting the progression of HD. Several studies have aimed so far to screen the microbiota composition in mouse models of HD and find out whether observed microbiome dysbiosis could affect the functions of the HD brain. This review summarizes ongoing research in the HD field and highlights the essential role of the intestine-brain axis in HD pathogenesis and progression. The review also puts a strong emphasis on indicating microbiome composition as a future target in the urgently needed therapy for this still incurable disease.

Microbiome-Metabolomics Analysis of the Impacts of Cryptosporidium muris Infection in BALB/C Mice

Cryptosporidium is a leading cause of diarrheal disease and mortality in young children worldwide. Cryptosporidium invades small intestinal epithelial cells and forms a unique intracellular niche, a process that may alter gut microbes and their production metabolites. However, the mechanism of interactions between gut microbes, metabolites, and parasites is poorly understood. Here, we first characterized the impacts of Cryptosporidium infection on gut microbiota using a microbiome-to-metabolome association study. BALB/c mice were gavaged with Cryptosporidium muris, and fecal samples were collected at 0, 7, 14, 21, and 28 days postinfection (dpi) to observe changes in the intestinal microbes of the body during parasite infection. The infected group had a significantly increased relative abundance of bacterial taxa, such as Lachnospiraceae and Prevotella (P < 0.05), associated with the biosynthesis of short-chain fatty acids (SCFAs). Metabolites related to the metabolic pathways, steroid hormone biosynthesis, and biosynthesis of unsaturated fatty acids pathway were upregulated at 7 dpi, indicating that related metabolites in the biosynthesis of unsaturated fatty acids may be essential for C. muris reproduction in vivo. The metabolites involved in metabolic pathways, bile secretion, and primary bile acid biosynthesis were upregulated at 14 dpi, and we speculate that these metabolites may be critical to the growth and development of Cryptosporidium oocysts in the host. Correlation analysis revealed that Firmicutes bacteria are significantly associated with α-linolenic acid metabolism pathways (P< 0.05). The gut microbiota changes dynamically, and the metabolites involved in fatty acid and bile acid biosynthesis may play important roles during cryptosporidiosis. Details of the gut microbiota and the metabolome after infection with Cryptosporidium may aid in the discovery of specific diagnostic markers and help us understand the changes in parasite metabolic pathways. IMPORTANCE Cryptosporidiosis is a gastrointestinal disease in humans and animals caused by the protozoan parasite Cryptosporidium. Control and treatment of the disease is challenging due to the lack of sensitive diagnostic tools and effective chemotherapy. The dynamics of gut microbiota and metabolites during Cryptosporidium infection may be the key to finding drugs and targets for parasite infection control. Our results indicate that C. muris infection can disrupt gut microbiota and metabolites, resulting in decreased bacterial abundance at the parasitic site. Unsaturated fatty acid pathway biosynthesis-related metabolites are significantly elevated at the patent period. Interestingly, the metabolite pathway that significantly elevated during peak parasite growth was bile acid, the metabolites of which may be important for the circulation of infection of Cryptosporidium oocysts in the host. The enhancing effects of short-chain fatty acid and bile acid metabolism on the growth and development of Cryptosporidium proposed in this study may provide a theoretical basis for future research on novel drugs and vaccines against this intestinal parasite.

Evaluation of gut microbiota of iranian patients with celiac disease, non-celiac wheat sensitivity, and irritable bowel syndrome: are there any similarities?

BACKGROUND AND AIMS

Individuals with celiac disease (CD), non-celiac wheat sensitivity (NCWS), and irritable bowel syndrome (IBS), show overlapping clinical symptoms and experience gut dysbiosis. A limited number of studies so far compared the gut microbiota among these intestinal conditions. This study aimed to investigate the similarities in the gut microbiota among patients with CD, NCWS, and IBS in comparison to healthy controls (HC).

MATERIALS AND METHODS

In this prospective study, in total 72 adult subjects, including CD (n = 15), NCWS (n = 12), IBS (n = 30), and HC (n = 15) were recruited. Fecal samples were collected from each individual. A quantitative real-time PCR (qPCR) test using 16S ribosomal RNA was conducted on stool samples to assess the relative abundance of Firmicutes, Bacteroidetes, Bifidobacterium spp., and Lactobacillus spp.

RESULTS

In all groups, Firmicutes and Lactobacillus spp. had the highest and lowest relative abundance respectively. The phylum Firmicutes had a higher relative abundance in CD patients than other groups. On the other hand, the phylum Bacteroidetes had the highest relative abundance among healthy subjects but the lowest in patients with NCWS. The relative abundance of Bifidobacterium spp. was lower in subjects with CD (P = 0.035) and IBS (P = 0.001) compared to the HCs. Also, the alteration of Firmicutes to Bacteroidetes ratio (F/B ratio) was statistically significant in NCWS and CD patients compared to the HCs (P = 0.05).

CONCLUSION

The principal coordinate analysis (PCoA), as a powerful multivariate analysis, suggested that the investigated gut microbial profile of patients with IBS and NCWS share more similarities to the HCs. In contrast, patients with CD had the most dissimilarity compared to the other groups in the context of the studied gut microbiota.

A protocol for the integration of multi-omics bioinformatics: Mechanism of acupuncture as an adjunctive therapy for alcohol use disorder

Background

Alcohol use disorder (AUD) has become a significant global factor in various diseases. As a non-pharmacological therapy, certain therapeutic potential has been found in acupuncture; however, in-depth mechanistic studies related to acupuncture for patients with AUD are still insufficient.

Methods

Based on a randomized control design and a multi-omics analysis plan, this protocol details the recruitment (42 AUD patients), group allocation (21 in acupuncture group vs. 21 in sham acupuncture group), intervention and follow-up (replacement drugs as a normal treatment, 2 weeks acupuncture duration, and 3 month follow-up), and data collection and analytical processes. For the clinical outcomes, in addition to the time required for alcohol withdrawal symptoms to subside as the primary outcome, changes in the alcohol withdrawal symptoms, alcohol craving, mood dysfunction, sleep disorder, fatigue, self-efficacy, gastrointestinal symptoms, the quality of life, and the relapse outcomes will be compared between the groups to confirm the acupuncture clinical effectiveness on alcohol withdraw. The gut microbiome and the fecal metabolomics will also be assessed to explore the association of the structure and the function of gut microflora and the mediation of acupuncture effect on AUD fully utilizing gut microflora multi-modal data and clinical information, via the combination of multi-omics methods, feature screening algorithms and appropriate models.

Discussion

The results of this study may help to strengthen clinical evidence of the mechanism of acupuncture intervention in patients with AUD, through understanding of the regulatory mechanism of acupuncture in the gut microbiome and its metabolism as well as AUD-related clinical manifestations.

Trial registration

Chinese Clinical Trial Registry ChiCTR2200058120. Registered on 24 Mar 2022.

Modulation of the gut-brain axis via the gut microbiota: a new era in treatment of amyotrophic lateral sclerosis

There are trillions of different microorganisms in the human digestive system. These gut microbes are involved in the digestion of food and its conversion into the nutrients required by the body. In addition, the gut microbiota communicates with other parts of the body to maintain overall health. The connection between the gut microbiota and the brain is known as the gut-brain axis (GBA), and involves connections via the central nervous system (CNS), the enteric nervous system (ENS), and endocrine and immune pathways. The gut microbiota regulates the central nervous system bottom-up through the GBA, which has prompted researchers to pay considerable attention to the potential pathways by which the gut microbiota might play a role in the prevention and treatment of amyotrophic lateral sclerosis (ALS). Studies with animal models of ALS have shown that dysregulation of the gut ecology leads to dysregulation of brain-gut signaling. This, in turn, induces changes in the intestinal barrier, endotoxemia, and systemic inflammation, which contribute to the development of ALS. Through the use of antibiotics, probiotic supplementation, phage therapy, and other methods of inducing changes in the intestinal microbiota that can inhibit inflammation and delay neuronal degeneration, the clinical symptoms of ALS can be alleviated, and the progression of the disease can be delayed. Therefore, the gut microbiota may be a key target for effective management and treatment of ALS.

The role of the microbiota-gut-brain axis in long-term neurodegenerative processes following traumatic brain injury

Traumatic brain injury (TBI) can be a devastating and debilitating disease to endure. Due to improvements in clinical practice, declining mortality rates have led to research into the long-term consequences of TBI. For example, the incidence and severity of TBI have been associated with an increased susceptibility of developing neurodegenerative disorders, such as Parkinson's or Alzheimer's disease. However, the mechanisms linking this alarming association are yet to be fully understood. Recently, there has been a groundswell of evidence implicating the microbiota-gut-brain axis in the pathogenesis of these diseases. Interestingly, survivors of TBI often report gastrointestinal complaints and animal studies have demonstrated gastrointestinal dysfunction and dysbiosis following injury. Autonomic dysregulation and chronic inflammation appear to be the main driver of these pathologies. Consequently, this review will explore the potential role of the microbiota-gut-brain axis in the development of neurodegenerative diseases following TBI.

Immunology and microbiome: Implications for motor systems

Immune-inflammatory mechanisms seem to play a relevant role in neurodegenerative disorders affecting motor systems, particularly Parkinson's disease, where activity changes in inflammatory cells and evidence of neuroinflammation in experimental models and patients is available. Amyotrophic lateral sclerosis is also characterized by neuroinflammatory changes that involve primarily glial cells, both microglia and astrocytes, as well as systemic immune dysregulation associated with more rapid progression. Similarly, the exploration of gut dysbiosis in these two prototypical neurodegenerative motor disorders is advancing rapidly. Altered composition of gut microbial constituents and related metabolic and putative functional pathways is supporting a pathophysiological link that is currently explored in preclinical, germ-free animal models. Less compelling, but still intriguing, evidence suggests that motor neurodevelopmental disorders, e.g., Tourette syndrome, are associated with abnormal trajectories of maturation that include also immune system development. Microglia has a key role also in these disorders, and new therapeutic avenues aiming at its modulation are exciting prospects. Preclinical and clinical research on the role of gut dysbiosis in Tourette syndrome and related behavioral disorders is still in its infancy, but early findings support the rationale to delve deeper into its contribution to neural and immune maturation abnormalities in its spectrum.

Untargeted metabolomics unravel serum metabolic alterations in smokers with hypertension

Background: Cigarette smoking is an important environmental risk factor for cardiovascular events of hypertension (HTN). Existing studies have provided evidence supporting altered gut microbiota by cigarette smoking, especially in hypertensive patients. Metabolic biomarkers play a central role in the functional potentials of the gut microbiome but are poorly characterized in hypertensive smokers. To explore whether serum metabolomics signatures and compositions of HTN patients were varied in smokers, and investigate their connecting relationship to gut microbiota, the serum metabolites were examined in untreated hypertensive patients using untargeted liquid chromatography-mass spectrometry (LC/MS) analysis. Results: A dramatic difference and clear separation in community features of circulating metabolomics members were seen in smoking HTN patients compared with the non-smoking controls, according to partial least squares discrimination analysis (PLS-DA) and orthogonal partial least squares discrimination analysis (OPLS-DA). Serum metabolic profiles and compositions of smoking patients with HTN were significantly distinct from the controls, and were characterized by enrichment of 12-HETE, 7-Ketodeoxycholic acid, Serotonin, N-Stearoyl tyrosine and Deoxycholic acid glycine conjugate, and the depletion of Tetradecanedioic acid, Hippuric acid, Glyceric acid, 20-Hydroxyeicosatetraenoic acid, Phenylpyruvic acid and Capric acid. Additionally, the metabolome displayed prominent functional signatures, with a majority proportion of the metabolites identified to be discriminating between groups distributed in Starch and sucrose metabolism, Caffeine metabolism, Pyruvate metabolism, Glycine, serine and threonine metabolism, and Phenylalanine metabolic pathways. Furthermore, the observation of alterations in metabolites associated with intestinal microbial taxonomy indicated that these metabolic members might mediate the effects of gut microbiome on the smoking host. Indeed, the metabolites specific to smoking HTNs were strongly organized into co-abundance networks, interacting with an array of clinical parameters, including uric acid (UA), low-denstiy lipoprotein cholesterol (LDLC) and smoking index. Conclusions: In conclusion, we demonstrated disparate circulating blood metabolome composition and functional potentials in hypertensive smokers, showing a linkage between specific metabolites in blood and the gut microbiome.

Gut microbiota links with cognitive impairment in amyotrophic lateral sclerosis: a multi-omics study

Recently, cognitive impairments (CI) and behavioral abnormalities in patients with amyotrophic lateral sclerosis (ALS) have been reported. However, the underlying mechanisms have been poorly understood. In the current study, we explored the role of gut microbiota in CI of ALS patients. We collected fecal samples from 35 ALS patients and 35 healthy controls. The cognitive function of the ALS patients was evaluated using the Edinburgh Cognitive and Behavioral ALS Screen. We analyzed these samples by using 16S rRNA gene sequencing as well as both untargeted and targeted (bile acids) metabolite mapping between patients with CI and patients with normal cognition (CN). We found altered gut microbial communities and a lower ratio of Firmicutes/ Bacteroidetes in the CI group, compared with the CN group. In addition, the untargeted metabolite mapping revealed that 26 and 17 metabolites significantly increased and decreased, respectively, in the CI group, compared with the CN group. These metabolites were mapped to the metabolic pathways associated with bile acids. We further found that cholic acid and chenodeoxycholic acid were significantly lower in the CI group than in the CN group. In conclusion, we found that the gut microbiota and its metabolome profile differed between ALS patients with and without CI and that the altered bile acid profile in fecal samples was significantly associated with CI in ALS patients. These results need to be replicated in larger studies in the future.

Target Metabolites to Slow Down Progression of Amyotrophic Lateral Sclerosis in Mice

Microbial metabolites affect the neuron system and muscle cell functions. Amyotrophic lateral sclerosis (ALS) is a multifactorial neuromuscular disease. Our previous study has demonstrated elevated intestinal inflammation and dysfunction of the microbiome in patients with ALS and an ALS mouse model (human-SOD1^G93A transgenic mice). However, the metabolites in ALS progression are unknown. Using an unbiased global metabolomic measurement and targeted measurement, we investigated the longitudinal changes of fecal metabolites in SOD1^G93A mice over the course of 13 weeks. We further compared the changes of metabolites and inflammatory response in age-matched wild-type (WT) and SOD1^G93A mice treated with the bacterial product butyrate. We found changes in carbohydrate levels, amino acid metabolism, and the formation of gamma-glutamyl amino acids. Shifts in several microbially contributed catabolites of aromatic amino acids agree with butyrate-induced changes in the composition of the gut microbiome. Declines in gamma-glutamyl amino acids in feces may stem from differential expression of gamma-glutamyltransferase (GGT) in response to butyrate administration. Due to the signaling nature of amino acid-derived metabolites, these changes indicate changes in inflammation, e.g., histamine, and contribute to differences in systemic levels of neurotransmitters, e.g., γ-Aminobutyric acid (GABA) and glutamate. Butyrate treatment was able to restore some of the healthy metabolites in ALS mice. Moreover, microglia in the spinal cord were measured by IBA1 staining. Butyrate treatment significantly suppressed the IBA1 level in the SOD1^G93A mice. Serum IL-17 and LPS were significantly reduced in the butyrate-treated SOD1^G93A mice. We have demonstrated an inter-organ communications link among microbial metabolites, neuroactive metabolites from the gut, and inflammation in ALS progression. The study supports the potential to use metabolites as ALS hallmarks and for treatment.

Ozone modified hypothalamic signaling enhancing thermogenesis in the TDP-43A315T transgenic model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS), a devastating progressive neurodegenerative disease, has no effective treatment. Recent evidence supports a strong metabolic component in ALS pathogenesis. Indeed, metabolic abnormalities in ALS correlate to disease susceptibility and progression, raising additional therapeutic targets against ALS. Ozone (O₃), a natural bioactive molecule, has been shown to elicit beneficial effects to reduce metabolic disturbances and improved motor behavior in TDP-43^A315T mice. However, it is fundamental to determine the mechanism through which O₃ acts in ALS. To characterize the association between O₃ exposure and disease-associated weight loss in ALS, we assessed the mRNA and protein expression profile of molecular pathways with a main role in the regulation of the metabolic homeostasis on the hypothalamus and the brown adipose tissue (BAT) at the disease end-stage, in TDP-43^A315T mice compared to age-matched WT littermates. In addition, the impact of O₃ exposure on the faecal bacterial community diversity, by Illumina sequencing, and on the neuromuscular junctions (NMJs), by confocal imaging, were analysed. Our findings suggest the effectiveness of O₃ exposure to induce metabolic effects in the hypothalamus and BAT of TDP-43^A315T mice and could be a new complementary non-pharmacological approach for ALS therapy.

What Are the Key Gut Microbiota Involved in Neurological Diseases? A Systematic Review

There is a growing body of evidence highlighting there are significant changes in the gut microbiota composition and relative abundance in various neurological disorders. We performed a systematic review of the different microbiota altered in a wide range of neurological disorders (Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis, and stroke). Fifty-two studies were included representing 5496 patients. At the genus level, the most frequently involved microbiota are Akkermansia, Faecalibacterium, and Prevotella. The overlap between the pathologies was strongest for MS and PD, sharing eight genera (Akkermansia, Butyricicoccus, Bifidobacterium, Coprococcus, Dorea, Faecalibacterium, Parabacteroides, and Prevotella) and PD and stroke, sharing six genera (Enterococcus, Faecalibacterium, Lactobacillus, Parabacteroides, Prevotella, and Roseburia). The identification signatures overlapping for AD, PD, and MS raise the question of whether these reflect a common etiology or rather common consequence of these diseases. The interpretation is hampered by the low number and low power for AD, ALS, and stroke with ample opportunity for false positive and false negative findings.

A review of the preclinical and clinical studies on the role of the gut microbiome in aging and neurodegenerative diseases and its modulation

As the world population ages, the burden of age-related health problems grows, creating a greater demand for new novel interventions for healthy aging. Advancing aging is related to a loss of beneficial mutualistic microbes in the gut microbiota caused by extrinsic and intrinsic factors such as diet, sedentary lifestyle, sleep deprivation, circadian rhythms, and oxidative stress, which emerge as essential elements in controlling and prolonging life expectancy of healthy aging. This condition is known as gut dysbiosis, and it affects normal brain function via the brain-gut microbiota (BGM) axis, which is a bidirectional link between the gastrointestinal tract (GIT) and the central nervous system (CNS) that leads to the emergence of brain disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). Here, we reviewed the role of the gut microbiome in aging and neurodegenerative diseases, as well as provided a comprehensive review of recent findings from preclinical and clinical studies to present an up-to-date overview of recent advances in developing strategies to modulate the intestinal microbiome by probiotic administration, dietary intervention, fecal microbiota transplantation (FMT), and physical activity to address the aging process and prevent neurodegenerative diseases. The findings of this review will provide researchers in the fields of aging and the gut microbiome design innovative studies that leverage results from preclinical and clinical studies to better understand the nuances of aging, gut microbiome, and neurodegenerative diseases.

The gastrointestinal and microbiome impact of a resistant starch blend from potato, banana, and apple fibers: A randomized clinical trial using smart caps

The gastrointestinal (GI) impact of fibers including resistant starch (RS) consumption depends on various types and amounts of fibers, the initial microbiome states, and accurate intake measurements. A randomized clinical trial evaluated the GI impact of varying doses of a novel resistant starch blend (RSB) with smart cap monitoring. RSB contained at least 50% RS and was a proprietary mixture of a potato starch, green banana flour, and apple fiber powder (a source of apple pectin, not resistant starch). The study design randomized participants to one of four arms: 10 g/day of potato starch (0 RSB), 10 g/day of RSB, 10 to 20 to 20 g/day of RSB or 10 to 20 to 30 g/day RSB for two-week intervals over 6 weeks. Results confirmed that while resistant starch of approximately 5 g per day improves GI symptoms at 2, 4, and 6 weeks, it did not demonstrate a detectable effect on short chain fatty acids. Increasing doses of the blend (RSB) led to a decrease in the diarrhea score. Using an estimate of total consumption of RSB based on smart cap recordings of container openings and protocol-specified doses of RSB, a reduction in the sleep disturbance score was associated with higher RSB dose. The exploratory microbiome evaluation demonstrated that among the 16S rRNA gene sequences most associated with the consumption of the novel blend RSB, two belong to taxa of notable interest to human health: Faecalibacterium and Akkermansia.

Diet-microbiome-gut-brain nexus in acute and chronic brain injury

In recent years, appreciation for the gut microbiome and its relationship to human health has emerged as a facilitator of maintaining healthy physiology and a contributor to numerous human diseases. The contribution of the microbiome in modulating the gut-brain axis has gained significant attention in recent years, extensively studied in chronic brain injuries such as Epilepsy and Alzheimer’s Disease. Furthermore, there is growing evidence that gut microbiome also contributes to acute brain injuries like stroke(s) and traumatic brain injury. Microbiome-gut-brain communications are bidirectional and involve metabolite production and modulation of immune and neuronal functions. The microbiome plays two distinct roles: it beneficially modulates immune system and neuronal functions; however, abnormalities in the host’s microbiome also exacerbates neuronal damage or delays the recovery from acute injuries. After brain injury, several inflammatory changes, such as the necrosis and apoptosis of neuronal tissue, propagates downward inflammatory signals to disrupt the microbiome homeostasis; however, microbiome dysbiosis impacts the upward signaling to the brain and interferes with recovery in neuronal functions and brain health. Diet is a superlative modulator of microbiome and is known to impact the gut-brain axis, including its influence on acute and neuronal injuries. In this review, we discussed the differential microbiome changes in both acute and chronic brain injuries, as well as the therapeutic importance of modulation by diets and probiotics. We emphasize the mechanistic studies based on animal models and their translational or clinical relationship by reviewing human studies.