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Lever TE, Kloepper A, Welby L, Haney M, Fudge S, Seiller C, Kington S, Ballenger B, Nichols NL. Minimally Invasive Murine Laryngoscopy for Close-Up Imaging of Laryngeal Motion during Breathing and Swallowing. J Vis Exp 2023:10.3791/66089. [PMID: 38108389 PMCID: PMC11101017 DOI: 10.3791/66089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023] Open
Abstract
The larynx is an essential organ in mammals with three primary functions - breathing, swallowing, and vocalizing. A wide range of disorders are known to impair laryngeal function, which results in difficulty breathing (dyspnea), swallowing impairment (dysphagia), and/or voice impairment (dysphonia). Dysphagia, in particular, can lead to aspiration pneumonia and associated morbidity, recurrent hospitalization, and early mortality. Despite these serious consequences, existing treatments for laryngeal dysfunction are largely aimed at surgical and behavioral interventions that unfortunately do not typically restore normal laryngeal function, thus highlighting the urgent need for innovative solutions. To bridge this gap, we have been developing an experimental endoscopic approach to investigate laryngeal dysfunction in murine (i.e., mouse and rat) models. However, endoscopy in rodents is quite challenging due to their small size relative to current endoscope technology, anatomical differences in the upper airway, and the necessity for anesthesia to optimally access the larynx. Here, we describe a novel transoral laryngoscopy approach that permits close-up, unobstructed video imaging of laryngeal motion in mice and rats. Critical steps in the protocol include precise anesthesia management (to prevent overdosing that abolishes swallowing and/or risks respiratory distress-related mortality) and micromanipulator control of the endoscope (for stable video recording of laryngeal motion by a single researcher for subsequent quantification). Importantly, the protocol can be performed over time in the same animals to study the impact of various pathological conditions specifically on laryngeal function. A novel advantage of this protocol is the ability to visualize airway protection during swallowing, which is not possible in humans due to epiglottic inversion over the laryngeal inlet that obstructs the glottis from view. Rodents therefore provide a unique opportunity to specifically investigate the mechanisms of normal versus pathological laryngeal airway protection for the ultimate purpose of discovering treatments to effectively restore normal laryngeal function.
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Affiliation(s)
- Teresa E Lever
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine; Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine;
| | - Ashley Kloepper
- Department of Otolaryngology - Head and Neck Surgery, University of Missouri School of Medicine
| | - Lauren Welby
- Division of Otolaryngology - Head and Neck Surgery, Texas A&M Health Science Center College of Medicine - Baylor Scott & White
| | - Megan Haney
- Department of Veterinary Pathobiology, University of Missouri College of Veterinary Medicine
| | - Shakera Fudge
- Department of Veterinary Pathobiology, University of Missouri College of Veterinary Medicine
| | - Chase Seiller
- Department of Medicine, University of Missouri School of Medicine
| | - Sophia Kington
- Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine
| | | | - Nicole L Nichols
- Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine
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2
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Jin Z, Dong J, Wang Y, Liu Y. Exploring the potential of vagus nerve stimulation in treating brain diseases: a review of immunologic benefits and neuroprotective efficacy. Eur J Med Res 2023; 28:444. [PMID: 37853458 PMCID: PMC10585738 DOI: 10.1186/s40001-023-01439-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 10/09/2023] [Indexed: 10/20/2023] Open
Abstract
The vagus nerve serves as a critical connection between the central nervous system and internal organs. Originally known for its effectiveness in treating refractory epilepsy, vagus nerve stimulation (VNS) has shown potential for managing other brain diseases, including ischaemic stroke, traumatic brain injury, Parkinson's disease, and Alzheimer's disease. However, the precise mechanisms of VNS and its benefits for brain diseases are not yet fully understood. Recent studies have found that VNS can inhibit inflammation, promote neuroprotection, help maintain the integrity of the blood-brain barrier, have multisystemic modulatory effects, and even transmit signals from the gut flora to the brain. In this article, we will review several essential studies that summarize the current theories of VNS and its immunomodulatory effects, as well as the therapeutic value of VNS for brain disorders. By doing so, we aim to provide a better understanding of how the neuroimmune network operates and inspire future research in this field.
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Affiliation(s)
- Zeping Jin
- Department of Neurosurgery, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Jing Dong
- Department of Medical Engineering, Tsinghua University Yuquan Hospital, Beijing, People's Republic of China
| | - Yang Wang
- Department of Neurosurgery, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Yunpeng Liu
- Department of Neurosurgery, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People's Republic of China.
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3
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Chen S, Zhang P, Duan H, Wang J, Qiu Y, Cui Z, Yin Y, Wan D, Xie L. Gut microbiota in muscular atrophy development, progression, and treatment: New therapeutic targets and opportunities. Innovation (N Y) 2023; 4:100479. [PMID: 37539440 PMCID: PMC10394038 DOI: 10.1016/j.xinn.2023.100479] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/06/2023] [Indexed: 08/05/2023] Open
Abstract
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.
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Affiliation(s)
- Shujie Chen
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Department of Endocrinology and Metabolism, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
- Department of Rehabilitation Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510000, China
| | - Puxuan Zhang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Huimin Duan
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Department of Endocrinology and Metabolism, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
- Department of Rehabilitation Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510000, China
| | - Jie Wang
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Yuyueyang Qiu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Department of Biology, Grinnell College, Grinnell, IA 501122, USA
| | - Zongbin Cui
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Yulong Yin
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- University of the Chinese Academy of Sciences, Beijing 101408, China
| | - Dan Wan
- Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
- University of the Chinese Academy of Sciences, Beijing 101408, China
| | - Liwei Xie
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Department of Endocrinology and Metabolism, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
- Department of Rehabilitation Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510000, China
- School of Public Health, Xinxiang Medical University, Xinxiang 453003, China
- Department of Stomatology, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde, Foshan), Foshan 528308, China
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4
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Zhang S, He H, Wang Y, Wang X, Liu X. Transcutaneous auricular vagus nerve stimulation as a potential novel treatment for polycystic ovary syndrome. Sci Rep 2023; 13:7721. [PMID: 37173458 PMCID: PMC10182028 DOI: 10.1038/s41598-023-34746-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/06/2023] [Indexed: 05/15/2023] Open
Abstract
Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of childbearing age. The etiology of PCOS is multifactorial, and current treatments for PCOS are far from satisfactory. Recently, an imbalanced autonomic nervous system (ANS) with sympathetic hyperactivity and reduced parasympathetic nerve activity (vagal tone) has aroused increasing attention in the pathogenesis of PCOS. In this paper, we review an innovative therapy for the treatment of PCOS and related co-morbidities by targeting parasympathetic modulation based on non-invasive transcutaneous auricular vagal nerve stimulation (ta-VNS). In this work, we present the role of the ANS in the development of PCOS and describe a large number of experimental and clinical reports that support the favorable effects of VNS/ta-VNS in treating a variety of symptoms, including obesity, insulin resistance, type 2 diabetes mellitus, inflammation, microbiome dysregulation, cardiovascular disease, and depression, all of which are also commonly present in PCOS patients. We propose a model focusing on ta-VNS that may treat PCOS by (1) regulating energy metabolism via bidirectional vagal signaling; (2) reversing insulin resistance via its antidiabetic effect; (3) activating anti-inflammatory pathways; (4) restoring homeostasis of the microbiota-gut-brain axis; (5) restoring the sympatho-vagal balance to improve CVD outcomes; (6) and modulating mental disorders. ta-VNS is a safe clinical procedure and it might be a promising new treatment approach for PCOS, or at least a supplementary treatment for current therapeutics.
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Affiliation(s)
- Shike Zhang
- Southern University of Science and Technology Yantian Hospital, Shenzhen, 518081, China
- Shenzhen Yantian District People's Hospital, Shenzhen, 518081, China
| | - Hui He
- First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China.
| | - Yu Wang
- First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Xiao Wang
- First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
| | - Xiaofang Liu
- Chinese People's Liberation Army General Hospital, Beijing, 100853, China
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5
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Are neuromodulation interventions associated with changes in the gut microbiota? A systematic review. Neuropharmacology 2023; 223:109318. [PMID: 36334762 DOI: 10.1016/j.neuropharm.2022.109318] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/21/2022] [Accepted: 10/30/2022] [Indexed: 11/11/2022]
Abstract
The microbiota-gut-brain axis (MGBA) refers to the bidirectional communication between the brain and the gut microbiota and recent studies have linked the MGBA to health and disease. Research has so far investigated this axis mainly from microbiota to brain but less is known about the other direction. One approach to examine the MGBA from brain to microbiota is through understanding if and how neuromodulation might impact microbiota. Neuromodulation encompasses a wide range of stimulation techniques and is used to treat neurological, psychiatric and metabolic disorders, like Parkinson's Disease, depression and obesity. Here, we performed a systematic review to investigate whether neuromodulation is associated with subsequent changes in the gut microbiota. Searches in PsycINFO and MEDLINE were performed up to March 2022. Included studies needed to be clinical or preclinical studies comparing the effects of deep brain stimulation, electroconvulsive therapy, repetitive transcranial magnetic stimulation, transcranial direct current stimulation or vagal nerve stimulation on the gut microbiota before and after treatment or between active and control groups. Seven studies were identified. Neuromodulation was associated with changes in relative bacterial abundances, but not with (changes in) α-diversity or β-diversity. Summarizing, currently reported findings suggest that neuromodulation interventions are associated with moderate changes in the gut microbiome. However, findings remain inconclusive due to the limited number and varying quality of included studies, as well as the large heterogeneity between studies. More research is required to more conclusively establish whether, and if so, via which mechanism(s) of action neuromodulation interventions might influence the gut microbiota.
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6
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Nowakowska M, Üçal M, Charalambous M, Bhatti SFM, Denison T, Meller S, Worrell GA, Potschka H, Volk HA. Neurostimulation as a Method of Treatment and a Preventive Measure in Canine Drug-Resistant Epilepsy: Current State and Future Prospects. Front Vet Sci 2022; 9:889561. [PMID: 35782557 PMCID: PMC9244381 DOI: 10.3389/fvets.2022.889561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/23/2022] [Indexed: 11/28/2022] Open
Abstract
Modulation of neuronal activity for seizure control using various methods of neurostimulation is a rapidly developing field in epileptology, especially in treatment of refractory epilepsy. Promising results in human clinical practice, such as diminished seizure burden, reduced incidence of sudden unexplained death in epilepsy, and improved quality of life has brought neurostimulation into the focus of veterinary medicine as a therapeutic option. This article provides a comprehensive review of available neurostimulation methods for seizure management in drug-resistant epilepsy in canine patients. Recent progress in non-invasive modalities, such as repetitive transcranial magnetic stimulation and transcutaneous vagus nerve stimulation is highlighted. We further discuss potential future advances and their plausible application as means for preventing epileptogenesis in dogs.
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Affiliation(s)
- Marta Nowakowska
- Research Unit of Experimental Neurotraumatology, Department of Neurosurgery, Medical University of Graz, Graz, Austria
| | - Muammer Üçal
- Research Unit of Experimental Neurotraumatology, Department of Neurosurgery, Medical University of Graz, Graz, Austria
| | - Marios Charalambous
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Sofie F. M. Bhatti
- Small Animal Department, Faculty of Veterinary Medicine, Small Animal Teaching Hospital, Ghent University, Merelbeke, Belgium
| | - Timothy Denison
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Sebastian Meller
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | | | - Heidrun Potschka
- Faculty of Veterinary Medicine, Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Holger A. Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
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7
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Sun J, Huang T, Debelius JW, Fang F. Gut microbiome and amyotrophic lateral sclerosis: A systematic review of current evidence. J Intern Med 2021; 290:758-788. [PMID: 34080741 DOI: 10.1111/joim.13336] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS), characterized by a loss of motor neurons in the brain and spinal cord, is a relatively rare but currently incurable neurodegenerative disease. The global incidence of ALS is estimated as 1.75 per 100,000 person-years and the global prevalence is estimated as 4.1-8.4 per 100,000 individuals. Contributions from outside the central nervous system to the etiology of ALS have been increasingly recognized. Gut microbiome is one of the most quickly growing fields of research for ALS. In this article, we performed a comprehensive review of the results from existing animal and human studies, to provide an up-to-date summary of the current research on gut microbiome and ALS. In brief, we found relatively consistent results from animal studies, suggesting an altered gut microbiome composition in experimental ALS. Publication bias might however be a concern. Findings from human studies are largely inconclusive. A few animal and human studies demonstrated the usefulness of intervention with microbial-derived metabolites in modulating the disease progression of ALS. We discussed potential methodological concerns in these studies, including study design, statistical power, handling process of biospecimens and sequencing data, as well as statistical methods and interpretation of results. Finally, we made a few proposals for continued microbiome research in ALS, with the aim to provide valid, reproducible, and translatable findings.
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Affiliation(s)
- Jiangwei Sun
- Unit of Integrative Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Tingting Huang
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.,Department of Radiation Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
| | - Justine W Debelius
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Fang Fang
- Unit of Integrative Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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8
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Deep Transcranial Magnetic Stimulation Affects Gut Microbiota Composition in Obesity: Results of Randomized Clinical Trial. Int J Mol Sci 2021; 22:ijms22094692. [PMID: 33946648 PMCID: PMC8125086 DOI: 10.3390/ijms22094692] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023] Open
Abstract
Growing evidence highlights the crucial role of gut microbiota in affecting different aspects of obesity. Considering the ability of deep transcranial magnetic stimulation (dTMS) to modulate the cortical excitability, the reward system, and, indirectly, the autonomic nervous system (ANS), we hypothesized a potential role of dTMS in affecting the brain-gut communication pathways, and the gut microbiota composition in obesity. In a hospital setting, 22 subjects with obesity (5 M, 17 F; 44.9 ± 2.2 years; BMI 37.5 ± 1.0 kg/m2) were randomized into three groups receiving 15 sessions (3 per week for 5 weeks) of high frequency (HF), low frequency (LF) dTMS, or sham stimulation. Fecal samples were collected at baseline and after 5 weeks of treatment. Total bacterial DNA was extracted from fecal samples using the QIAamp DNA Stool Mini Kit (Qiagen, Italy) and analyzed by a metagenomics approach (Ion Torrent Personal Genome Machine). After 5 weeks, a significant weight loss was found in HF (HF: −4.1 ± 0.8%, LF: −1.9 ± 0.8%, sham: −1.3 ± 0.6%, p = 0.042) compared to LF and sham groups, associated with a decrease in norepinephrine compared to baseline (HF: −61.5 ± 15.2%, p < 0.01; LF: −31.8 ± 17.1%, p < 0.05; sham: −35.8 ± 21.0%, p > 0.05). Furthermore, an increase in Faecalibacterium (+154.3% vs. baseline, p < 0.05) and Alistipes (+153.4% vs. baseline, p < 0.05) genera, and a significant decrease in Lactobacillus (−77.1% vs. baseline, p < 0.05) were found in HF. Faecalibacterium variations were not significant compared to baseline in the other two groups (LF: +106.6%, sham: +27.6%; p > 0.05) as well as Alistipes (LF: −54.9%, sham: −15.1%; p > 0.05) and Lactobacillus (LF: −26.0%, sham: +228.3%; p > 0.05) variations. Norepinephrine change significantly correlated with Bacteroides (r2 = 0.734; p < 0.05), Eubacterium (r2 = 0.734; p < 0.05), and Parasutterella (r2 = 0.618; p < 0.05) abundance variations in HF. In conclusion, HF dTMS treatment revealed to be effective in modulating gut microbiota composition in subjects with obesity, reversing obesity-associated microbiota variations, and promoting bacterial species representative of healthy subjects with anti-inflammatory properties.
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9
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Boddy SL, Giovannelli I, Sassani M, Cooper-Knock J, Snyder MP, Segal E, Elinav E, Barker LA, Shaw PJ, McDermott CJ. The gut microbiome: a key player in the complexity of amyotrophic lateral sclerosis (ALS). BMC Med 2021; 19:13. [PMID: 33468103 PMCID: PMC7816375 DOI: 10.1186/s12916-020-01885-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Much progress has been made in mapping genetic abnormalities linked to amyotrophic lateral sclerosis (ALS), but the majority of cases still present with no known underlying cause. Furthermore, even in families with a shared genetic abnormality there is significant phenotypic variability, suggesting that non-genetic elements may modify pathogenesis. Identification of such disease-modifiers is important as they might represent new therapeutic targets. A growing body of research has begun to shed light on the role played by the gut microbiome in health and disease with a number of studies linking abnormalities to ALS. MAIN BODY The microbiome refers to the genes belonging to the myriad different microorganisms that live within and upon us, collectively known as the microbiota. Most of these microbes are found in the intestines, where they play important roles in digestion and the generation of key metabolites including neurotransmitters. The gut microbiota is an important aspect of the environment in which our bodies operate and inter-individual differences may be key to explaining the different disease outcomes seen in ALS. Work has begun to investigate animal models of the disease, and the gut microbiomes of people living with ALS, revealing changes in the microbial communities of these groups. The current body of knowledge will be summarised in this review. Advances in microbiome sequencing methods will be highlighted, as their improved resolution now enables researchers to further explore differences at a functional level. Proposed mechanisms connecting the gut microbiome to neurodegeneration will also be considered, including direct effects via metabolites released into the host circulation and indirect effects on bioavailability of nutrients and even medications. CONCLUSION Profiling of the gut microbiome has the potential to add an environmental component to rapidly advancing studies of ALS genetics and move research a step further towards personalised medicine for this disease. Moreover, should compelling evidence of upstream neurotoxicity or neuroprotection initiated by gut microbiota emerge, modification of the microbiome will represent a potential new avenue for disease modifying therapies. For an intractable condition with few current therapeutic options, further research into the ALS microbiome is of crucial importance.
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Affiliation(s)
- Sarah L Boddy
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Ilaria Giovannelli
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Matilde Sassani
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Johnathan Cooper-Knock
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Michael P Snyder
- Stanford Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, USA
| | - Eran Segal
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot, Israel
| | - Eran Elinav
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
- Division of Cancer-Microbiome Research, DKFZ, Heidelberg, Germany
| | - Lynne A Barker
- Centre for Behavioural Science and Applied Psychology, Sheffield Hallam University, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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10
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Lee NN, Bidot WA, Ericsson AC, Franklin CL. Effects of Giardia lamblia Colonization and Fenbendazole Treatment on Canine Fecal Microbiota. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2020; 59. [PMID: 32370821 PMCID: PMC7338874 DOI: 10.30802/aalas-jaalas-19-000113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/07/2019] [Accepted: 12/20/2019] [Indexed: 12/18/2022]
Abstract
The gut microbiota (GM) is the sum of hundreds of distinct microbial species that can equal or outnumber their host'ssomatic cells. The GM influences a multitude of physiologic and immunologic processes in the host, and changes in the GM have been shown to alter the phenotypes of animal models. Previous studies using rodents have also shown that the composition of the GM is affected by many factors, including diet, husbandry, housing, and the genetic background of the animals. However, limited information exists about factors that may modulate GM in other laboratory species, such as dogs. We sought to eliminate sporadic Giardia colonization of dogs using fenbendazole (FBZ), an antiprotozoal widely used in biomedical research dog colonies. Concerns that FBZ could have inadvertent effects on the canine GM led us to assess GM over the course of treatment. FBZ (50 mg/kg) was given orally to all dogs in 3 different facilities (n = 19 to 25) for 10 consecutive days. Fecal samples were obtained 2 d before the initiation of treatment, on the last day of treatment, and 2 wk after the completion of treatment. Targeted 16S rRNA gene sequencing was used to analyze fecal microbiota. All dogs were clinically normal throughout the sample collection period. Statistical analyses of data showed significant differences between dogs housed in the 3 different facilities, further emphasizing the effect of housing and husbandry factors on the GM. However,negligible differences were seen between time points, indicating that FBZ did not significantly alter the canine GM. Comparison of the GM of Giardia lamblia positive and negative dogs revealed no significant difference between the 2 groups. These findings suggest that FBZ can be used therapeutically in dogs with minimal impact on the GM. Furthermore, the presence ofG. lamblia in clinically normal animals may not be sufficient to influence the normal canine microbiota.
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Affiliation(s)
- Naomi N Lee
- Comparative Medicine Program, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
| | - Willie A Bidot
- Comparative Medicine Program, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
| | - Aaron C Ericsson
- Comparative Medicine Program, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
| | - Craig L Franklin
- Comparative Medicine Program, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
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11
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Erber AC, Cetin H, Berry D, Schernhammer ES. The role of gut microbiota, butyrate and proton pump inhibitors in amyotrophic lateral sclerosis: a systematic review. Int J Neurosci 2019; 130:727-735. [PMID: 31870202 DOI: 10.1080/00207454.2019.1702549] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Aim of the study: We conducted a systematic review on existing literature in humans and animals, linking the gut microbiome with amyotrophic lateral sclerosis (ALS). Additionally, we sought to explore the role of the bacterially produced metabolite butyrate as well as of proton pump inhibitors (PPIs) in these associations.Materials and methods: Following PRISMA guidelines for systematic literature reviews, four databases (Medline, Scopus, Embase and Web of Science) were searched and screened by two independent reviewers against defined inclusion criteria. Six studies in humans and six animal studies were identified, summarized and reviewed.Results: Overall, the evidence accrued to date is supportive of changes in the gut microbiome being associated with ALS risk, and potentially progression, though observational studies are small (describing a total of 145 patients with ALS across all published studies), and not entirely conclusive.Conclusions: With emerging studies beginning to apply metagenome sequencing, more clarity regarding the importance and promise of the gut microbiome in ALS can be expected. Future studies may also help establish the therapeutic potential of butyrate, and the role of PPIs in these associations.
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Affiliation(s)
- Astrid C Erber
- Department of Epidemiology, Center for Public Health, Medical University of Vienna, Vienna, Austria.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Headington, Oxford, UK
| | - Hakan Cetin
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - David Berry
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Function, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.,Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
| | - Eva S Schernhammer
- Department of Epidemiology, Center for Public Health, Medical University of Vienna, Vienna, Austria.,Channing Division of Network Medicine, Harvard Medical School, Boston, MA, USA
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Neuroimmune Interactions in the Gut and Their Significance for Intestinal Immunity. Cells 2019; 8:cells8070670. [PMID: 31269754 PMCID: PMC6679154 DOI: 10.3390/cells8070670] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 12/12/2022] Open
Abstract
Inflammatory bowel diseases (IBD) have a complex, multifactorial pathophysiology with an unmet need for effective treatment. This calls for novel strategies to improve disease outcome and quality of life for patients. Increasing evidence suggests that autonomic nerves and neurotransmitters, as well as neuropeptides, modulate the intestinal immune system, and thereby regulate the intestinal inflammatory processes. Although the autonomic nervous system is classically divided in a sympathetic and parasympathetic branch, both play a pivotal role in the crosstalk with the immune system, with the enteric nervous system acting as a potential interface. Pilot clinical trials that employ vagus nerve stimulation to reduce inflammation are met with promising results. In this paper, we review current knowledge on the innervation of the gut, the potential of cholinergic and adrenergic systems to modulate intestinal immunity, and comment on ongoing developments in clinical trials.
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