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Frontiers in Psychiatry 2020Cumulative evidence shows a linkage between gut microbiota pattern and depression through the brain-gut microbiome axis. The aim of this systematic review was to...
Cumulative evidence shows a linkage between gut microbiota pattern and depression through the brain-gut microbiome axis. The aim of this systematic review was to identify the alterations of the gut microbiota patterns in people with depression compared to healthy controls. A comprehensive literature search of human studies, published between January 2000 and June 2019, was reviewed. The key words included gastrointestinal microbiome, gut microbiome, microbiota, depression, depressive symptoms, and depressive disorder. The systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Nine articles met the eligibility criteria. Disparities in α-diversity and β-diversity of the microbiota existed in people with depression compared to healthy controls. At the phylum level, there were inconsistencies in the abundance of , , . However, high abundance in and phyla were observed in people with depression. On the family level, high abundance of , , , , , , , , , , , , , low abundance of , , , , , , and were observed in people with depression. On the genus level, high abundance of , , , , , , , , , , , , , , , , , , , , , , , and low abundance of , , , , , , , and were found in people with depression. Alteration of gut microbiome patterns was evident in people with depression. Further evidence is warranted to allow for the translation of microbiome findings toward innovative clinical strategies that may improve treatment outcomes in people with depression.
PubMed: 32587537
DOI: 10.3389/fpsyt.2020.00541 -
Nutrients Mar 2020Autism spectrum disorder (ASD) is a public health problem and has a prevalence of 0.6%-1.7% in children. As well as psychiatric symptoms, dysbiosis and gastrointestinal... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Autism spectrum disorder (ASD) is a public health problem and has a prevalence of 0.6%-1.7% in children. As well as psychiatric symptoms, dysbiosis and gastrointestinal comorbidities are also frequently reported. The gut-brain microbiota axis suggests that there is a form of communication between microbiota and the brain underlying some neurological disabilities. The aim of this study is to describe and compare the composition of gut microbiota in children with and without ASD.
METHODS
Electronic databases were searched as far as February 2020. Meta-analyses were performed using RevMan5.3 to estimate the overall relative abundance of gut bacteria belonging to 8 phyla and 17 genera in children with ASD and controls.
RESULTS
We included 18 studies assessing a total of 493 ASD children and 404 controls. The microbiota was mainly composed of the phyla Bacteroidetes, Firmicutes, and Actinobacteria, all of which were more abundant in the ASD children than in the controls. Children with ASD showed a significantly higher abundance of the genera , , , and and a lower percentage of and .
DISCUSSION
This meta-analysis suggests that there is a dysbiosis in ASD children which may influence the development and severity of ASD symptomatology. Further studies are required in order to obtain stronger evidence of the effectiveness of pre- or probiotics in reducing autistic behaviors.
Topics: Autism Spectrum Disorder; Bacteria; Child; Dysbiosis; Female; Gastrointestinal Microbiome; Humans; Male
PubMed: 32192218
DOI: 10.3390/nu12030792 -
Frontiers in Psychiatry 2019Autism spectrum disorder (ASD) is characterized by stereotyped behavior and deficits in communication and social interactions. Gastrointestinal (GI) dysfunction is an...
Autism spectrum disorder (ASD) is characterized by stereotyped behavior and deficits in communication and social interactions. Gastrointestinal (GI) dysfunction is an ASD-associated comorbidity, implying a potential role of the gut microbiota in ASD GI pathophysiology. Several recent studies found that autistic individuals harbor an altered bacterial gut microbiota. In some cases, remodeling the gut microbiota by antibiotic administration and microbiota transfer therapy reportedly alleviated the symptoms of ASD. However, there is little consensus on specific bacterial species that are similarly altered across individual studies. The aim of this study is to summarize previously published data and analyze the alteration of the relative abundance of bacterial genera in the gut microbiota in controls and individuals with ASD using meta-analysis. We analyzed nine studies, including 254 patients with ASD, and found that children with ASD had lower percentages of , , , and and a higher percentage of in the total detected microflora compared to controls. In contrast, children with ASD had lower abundance of , , , and and higher abundance of . This meta-analysis suggests an association between ASD and alteration of microbiota composition and warrants additional prospective cohort studies to evaluate the association of bacterial changes with ASD symptoms, which would provide further evidence for the precise microbiological treatment of ASD.
PubMed: 31404299
DOI: 10.3389/fpsyt.2019.00473 -
Frontiers in Psychiatry 2019Recently discovered relationships between the gastrointestinal microbiome and the brain have implications for psychiatric disorders, including major depressive disorder...
Recently discovered relationships between the gastrointestinal microbiome and the brain have implications for psychiatric disorders, including major depressive disorder (MDD). Bacterial transplantation from MDD patients to rodents produces depression-like behaviors. In humans, case-control studies have examined the gut microbiome in healthy and affected individuals. We systematically reviewed existing studies comparing gut microbial composition in MDD and healthy volunteers. A PubMed literature search combined the terms "depression," "depressive disorder," "stool," "fecal," "gut," and "microbiome" to identify human case-control studies that investigated relationships between MDD and microbiota quantified from stool. We evaluated the resulting studies, focusing on bacterial taxa that were different between MDD and healthy controls. Six eligible studies were found in which 50 taxa exhibited differences ( < 0.05) between patients with MDD and controls. Patient characteristics and methodologies varied widely between studies. Five phyla-, and -were represented; however, divergent results occurred across studies for all phyla. The largest number of differentiating taxa were within phylum , in which nine families and 12 genera differentiated the diagnostic groups. The majority of these families and genera were found to be statistically different between the two groups in two identified studies. Family differentiated the diagnostic groups in four studies (with an even split in directionality). Across all five phyla, nine genera were higher in MDD (, and ), six were lower (, and ), and six were divergent (, and ). We highlight mechanisms and products of bacterial metabolism as they may relate to the etiology of depression. No consensus has emerged from existing human studies of depression and gut microbiome concerning which bacterial taxa are most relevant to depression. This may in part be due to differences in study design. Given that bacterial functions are conserved across taxonomic groups, we propose that studying microbial functioning may be more productive than a purely taxonomic approach to understanding the gut microbiome in depression.
PubMed: 30804820
DOI: 10.3389/fpsyt.2019.00034 -
International Journal of Gynecological... Sep 2017Worldwide, 1,470,900 women are diagnosed yearly with a gynecological malignancy (21,000 in the UK). Some patients treated with pelvic radiotherapy develop chronic... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIM
Worldwide, 1,470,900 women are diagnosed yearly with a gynecological malignancy (21,000 in the UK). Some patients treated with pelvic radiotherapy develop chronic changes in their bowel function. This systematic review summarizes current research on the impact of cancer treatment on the gut and vaginal microbiome in women with a gynecological malignancy.
METHODS
The Preferred reporting Items for Systematic Reviews and Meta-analyses guidelines for systematic reviews were used to ensure transparent and complete reporting. Quantitative studies exploring the gut or vaginal microbiome in this patient cohort were included. Animal studies were excluded. There were no language restrictions.
RESULTS
No studies examined the possible effects of surgery or chemotherapy for gynecological cancers on the gut or vaginal microbiome.Three prospective cohort studies were identified using sequencing of changes in the gut microbiome reporting on a total of 23 women treated for gynecological cancer. All studies included patients treated with radiotherapy with a dosage ranging from 43.0 to 54.0 Gy. Two studies assessed gastrointestinal toxicity formally; 8 women (57%) developed grade 2 or 3 diarrhea during radiotherapy. The outcomes suggest a correlation between changes in the intestinal microbiome and receiving radiotherapy and showed a decrease in abundance and diversity of the intestinal bacterial species. Before radiotherapy, those who developed diarrhea had an increased abundance of Bacteroides, Dialister, and Veillonella (P < 0.01), and a decreased abundance of Clostridium XI and XVIII, Faecalibacterium, Oscillibacter, Parabacteroides, Prevotella, and unclassified bacteria (P < 0.05).
CONCLUSION
The limited evidence to date implies that larger studies including both the vaginal and gut microbiome in women treated for a gynecological malignancy are warranted to explore the impact of cancer treatments on the microbiome and its relation to developing long-term gastrointestinal toxicity. This may lead to new avenues to stratify those at risk and explore personalized treatment options and prevention of gastrointestinal consequences of cancer treatments.
Topics: Cohort Studies; Female; Gastrointestinal Microbiome; Genital Neoplasms, Female; Humans; Prospective Studies; Vagina
PubMed: 28590950
DOI: 10.1097/IGC.0000000000000999