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West ML, Hart S, Loughman A, Jacka FN, Staudacher HM, Abbaspour A, Phillipou A, Ruusunen A, Rocks T. Challenges and priorities for researching the gut microbiota in individuals living with anorexia nervosa. Int J Eat Disord 2023; 56:2001-2011. [PMID: 37548294 DOI: 10.1002/eat.24033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/10/2023] [Accepted: 07/19/2023] [Indexed: 08/08/2023]
Abstract
OBJECTIVE The gut microbiota is implicated in several symptoms and biological pathways relevant to anorexia nervosa (AN). Investigations into the role of the gut microbiota in AN are growing, with a specific interest in the changes that occur in response to treatment. Findings suggest that microbial species may be associated with some of the symptoms common in AN, such as depression and gastrointestinal disturbances (GID). Therefore, researchers believe the gut microbiota may have therapeutic relevance. Whilst research in this field is rapidly expanding, the unique considerations relevant to conducting gut microbiota research in individuals with AN must be addressed. METHOD We provide an overview of the published literature investigating the relationship between the gut microbiota and symptoms and behaviors present in AN, discuss important challenges in gut microbiota research, and offer recommendations for addressing these. We conclude by summarizing research design priorities for the field to move forward. RESULTS Several ways exist to reduce participant burden and accommodate challenges when researching the gut microbiota in individuals with AN. DISCUSSION Recommendations from this article are foreseen to encourage scientific rigor and thoughtful protocol planning for microbiota research in AN, including ways to reduce participant burden. Employing such methods will contribute to a better understanding of the role of the gut microbiota in AN pathophysiology and treatment. PUBLIC SIGNIFICANCE The field of gut microbiota research is rapidly expanding, including the role of the gut microbiota in anorexia nervosa. Thoughtful planning of future research will ensure appropriate data collection for meaningful interpretation while providing a positive experience for the participant. We present current challenges, recommendations for research design and priorities to facilitate the advancement of research in this field.
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Affiliation(s)
- Madeline L West
- Deakin University, IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Food & Mood Centre, School of Medicine, Barwon Health, Geelong, Australia
| | - Susan Hart
- Eating and Nutrition Research Group, School of Medicine, Western Sydney University, Cambelltown, Australia
- Nutrition Services, St Vincent's Health Network, Darlinghurst, Australia
- Translational Health Research Institute, Eating Disorders and Body Image, School of Medicine, Western Sydney University, Penrith, New South Wales, Australia
| | - Amy Loughman
- Deakin University, IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Food & Mood Centre, School of Medicine, Barwon Health, Geelong, Australia
| | - Felice N Jacka
- Deakin University, IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Food & Mood Centre, School of Medicine, Barwon Health, Geelong, Australia
- Centre for Adolescent Health, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Black Dog Institute, Randwick, New South Wales, Australia
- James Cook University, Townsville, Queensland, Australia
| | - Heidi M Staudacher
- Deakin University, IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Food & Mood Centre, School of Medicine, Barwon Health, Geelong, Australia
| | - Afrouz Abbaspour
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutetet, Solna, Stockholm, Sweden
| | - Andrea Phillipou
- Orygen, Melbourne, Victoria, Australia
- Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Psychological Sciences, Swinburne University of Technology, Melbourne, Victoria, Australia
- Department of Mental Health, St Vincent's Hospital, Melbourne, Victoria, Australia
- Department of Mental Health, Austin Health, Melbourne, Victoria, Australia
| | - Anu Ruusunen
- Deakin University, IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Food & Mood Centre, School of Medicine, Barwon Health, Geelong, Australia
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
- Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland
| | - Tetyana Rocks
- Deakin University, IMPACT - The Institute for Mental and Physical Health and Clinical Translation, Food & Mood Centre, School of Medicine, Barwon Health, Geelong, Australia
- Translational Health Research Institute, Eating Disorders and Body Image, School of Medicine, Western Sydney University, Penrith, New South Wales, Australia
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Elwyn R, Mitchell J, Kohn MR, Driver C, Hay P, Lagopoulos J, Hermens DF. Novel ketamine and zinc treatment for anorexia nervosa and the potential beneficial interactions with the gut microbiome. Neurosci Biobehav Rev 2023; 148:105122. [PMID: 36907256 DOI: 10.1016/j.neubiorev.2023.105122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
Anorexia nervosa (AN) is a severe illness with diverse aetiological and maintaining contributors including neurobiological, metabolic, psychological, and social determining factors. In addition to nutritional recovery, multiple psychological and pharmacological therapies and brain-based stimulations have been explored; however, existing treatments have limited efficacy. This paper outlines a neurobiological model of glutamatergic and γ-aminobutyric acid (GABA)-ergic dysfunction, exacerbated by chronic gut microbiome dysbiosis and zinc depletion at a brain and gut level. The gut microbiome is established early in development, and early exposure to stress and adversity contribute to gut microbial disturbance in AN, early dysregulation to glutamatergic and GABAergic networks, interoceptive impairment, and inhibited caloric harvest from food (e.g., zinc malabsorption, competition for zinc ions between gut bacteria and host). Zinc is a key part of glutamatergic and GABAergic networks, and also affects leptin and gut microbial function; systems dysregulated in AN. Low doses of ketamine in conjunction with zinc, could provide an efficacious combination to act on NMDA receptors and normalise glutamatergic, GABAergic and gut function in AN.
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Affiliation(s)
- Rosiel Elwyn
- Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia.
| | - Jules Mitchell
- Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia
| | - Michael R Kohn
- AYA Medicine Westmead Hospital, CRASH (Centre for Research into Adolescent's Health) Western Sydney Local Health District, Sydney University, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia
| | - Christina Driver
- Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia
| | - Phillipa Hay
- Translational Health Research Institute (THRI) School of Medicine, Western Sydney University, Campbelltown, NSW, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia
| | - Jim Lagopoulos
- Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia
| | - Daniel F Hermens
- Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, Australia; SouthWest Sydney Local Health District, Liverpool Hospital, Liverpool, NSW, Australia
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Vasiliu O. The current state of research for psychobiotics use in the management of psychiatric disorders-A systematic literature review. Front Psychiatry 2023; 14:1074736. [PMID: 36911130 PMCID: PMC9996157 DOI: 10.3389/fpsyt.2023.1074736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/03/2023] [Indexed: 02/25/2023] Open
Abstract
The need to find new therapeutic interventions in patients diagnosed with psychiatric disorders is supported by the data suggesting high rates of relapse, chronic evolution, therapeutic resistance, or lack of adherence and disability. The use of pre-, pro-, or synbiotics as add-ons in the therapeutic management of psychiatric disorders has been explored as a new way to augment the efficacy of psychotropics and to improve the chances for these patients to reach response or remission. This systematic literature review focused on the efficacy and tolerability of psychobiotics in the main categories of psychiatric disorders and it has been conducted through the most important electronic databases and clinical trial registers, using the PRISMA 2020 guidelines. The quality of primary and secondary reports was assessed using the criteria identified by the Academy of Nutrition and Diabetics. Forty-three sources, mostly of moderate and high quality, were reviewed in detail, and data regarding the efficacy and tolerability of psychobiotics was assessed. Studies exploring the effects of psychobiotics in mood disorders, anxiety disorders, schizophrenia spectrum disorders, substance use disorders, eating disorders, attention deficit hyperactivity disorder (ADHD), neurocognitive disorders, and autism spectrum disorders (ASD) were included. The overall tolerability of the interventions assessed was good, but the evidence to support their efficacy in specific psychiatric disorders was mixed. There have been identified data in favor of probiotics for patients with mood disorders, ADHD, and ASD, and also for the association of probiotics and selenium or synbiotics in patients with neurocognitive disorders. In several domains, the research is still in an early phase of development, e.g., in substance use disorders (only three preclinical studies being found) or eating disorders (one review was identified). Although no well-defined clinical recommendation could yet be formulated for a specific product in patients with psychiatric disorders, there is encouraging evidence to support further research, especially if focused on the identification of specific sub-populations that may benefit from this intervention. Several limitations regarding the research in this field should be addressed, i.e., the majority of the finalized trials are of short duration, there is an inherent heterogeneity of the psychiatric disorders, and the diversity of the explored Philae prevents the generalizability of the results from clinical studies.
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Affiliation(s)
- Octavian Vasiliu
- Department of Psychiatry, Dr. Carol Davila University Emergency Central Military Hospital, Bucharest, Romania
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Frostad S. Are the Effects of Malnutrition on the Gut Microbiota–Brain Axis the Core Pathologies of Anorexia Nervosa? Microorganisms 2022; 10:microorganisms10081486. [PMID: 35893544 PMCID: PMC9329996 DOI: 10.3390/microorganisms10081486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/29/2022] Open
Abstract
Anorexia nervosa (AN) is a disabling, costly, and potentially deadly illness. Treatment failure and relapse after treatment are common. Several studies have indicated the involvement of the gut microbiota–brain (GMB) axis. This narrative review hypothesizes that AN is driven by malnutrition-induced alterations in the GMB axis in susceptible individuals. According to this hypothesis, initial weight loss can voluntarily occur through dieting or be caused by somatic or psychiatric diseases. Malnutrition-induced alterations in gut microbiota may increase the sensitivity to anxiety-inducing gastrointestinal hormones released during meals, one of which is cholecystokinin (CCK). The experimental injection of a high dose of its CCK-4 fragment in healthy individuals induces panic attacks, probably via the stimulation of CCK receptors in the brain. Such meal-related anxiety attacks may take part in developing the clinical picture of AN. Malnutrition may also cause increased effects from appetite-reducing hormones that also seem to have roles in AN development and maintenance. The scientific background, including clinical, microbiological, and biochemical factors, of AN is discussed. A novel model for AN development and maintenance in accordance with this hypothesis is presented. Suggestions for future research are also provided.
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Affiliation(s)
- Stein Frostad
- Division of Psychiatry, Haukeland University Hospital, 5021 Bergen, Norway
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