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Annals of Nutrition & Metabolism 2020Differences in microbiota composition in children with autism spectrum disorder (ASD) compared to unaffected siblings and healthy controls have been reported in various...
INTRODUCTION
Differences in microbiota composition in children with autism spectrum disorder (ASD) compared to unaffected siblings and healthy controls have been reported in various studies. This study aims to systematically review the existing literature concerning the role of the gut microbiota in ASD.
METHODS
An extensive literature search was conducted using MEDLINE and EMBASE databases to identify studies (January 1966 through July 2019).
RESULTS
A total of 28 papers were included. The studies ranged from 12 to 104 participants who were aged between 2 and 18 years from various geographical areas. Majority of studies included faecal samples; however, 4 studies examined mucosal biopsies from different sites. The heterogeneity in ASD diagnostic methodology, gut site sampled and laboratory methods used made meta-analysis inappropriate. Species reported to be significantly higher in abundance in autistic children included Clostridium, Sutterella, Desulfovibrio and Lactobacillus. The findings are however inconsistent across studies. In addition, -potential confounding effects of antimicrobial use, gastrointestinal symptoms and diet on the gut microbiota are unclear due to generally poor assessment of these factors.
CONCLUSION
It is clear that the gut microbiota is altered in ASD, although further exploration is needed on whether this is a cause or an effect of the condition.
Topics: Adolescent; Autism Spectrum Disorder; Child; Child, Preschool; Feces; Gastrointestinal Diseases; Gastrointestinal Microbiome; Humans; Microbiota
PubMed: 31982866
DOI: 10.1159/000505363 -
Nutrients Jan 2019Oral glucosamine sulfate (GS) and chondroitin sulfate (CS), while widely marketed as joint-protective supplements, have limited intestinal absorption and are...
Oral glucosamine sulfate (GS) and chondroitin sulfate (CS), while widely marketed as joint-protective supplements, have limited intestinal absorption and are predominantly utilized by gut microbiota. Hence the effects of these supplements on the gut microbiome are of great interest, and may clarify their mode of action, or explain heterogeneity in therapeutic responses. We conducted a systematic review of animal and human studies reporting the effects of GS or CS on gut microbial composition. We searched MEDLINE, EMBASE, and Scopus databases for journal articles in English from database inception until July 2018, using search terms microbiome, microflora, intestinal microbiota/flora, gut microbiota/flora and glucosamine or chondroitin. Eight original articles reported the effects of GS or CS on microbiome composition in adult humans (four articles) or animals (four articles). Studies varied significantly in design, supplementation protocols, and microbiome assessment methods. There was moderate-quality evidence for an association between CS exposure and increased abundance of genus in the murine and human gut, and low-quality evidence for an association between CS exposure and an increase in species, an increase in family, and a decrease in . We discuss the possible metabolic implications of these changes for the host. For GS, evidence of effects on gut microbiome was limited to one low-quality study. This review highlights the importance of considering the potential influence of oral CS supplements on gut microbiota when evaluating their effects and safety for the host.
Topics: Animals; Bacteria; Chondroitin Sulfates; Gastrointestinal Microbiome; Glucosamine; Humans
PubMed: 30704054
DOI: 10.3390/nu11020294 -
Translational Psychiatry Jan 2019At present, the pathophysiology of autism spectrum disorder (ASD) remains unclear. Increasing evidence suggested that gut microbiota plays a critical role in...
At present, the pathophysiology of autism spectrum disorder (ASD) remains unclear. Increasing evidence suggested that gut microbiota plays a critical role in gastrointestinal symptoms and behavioral impairment in ASD patients. The primary aim of this systematic review is to investigate potential evidence for the characteristic dysbiosis of gut microbiota in ASD patients compared with healthy controls (HCs). The MEDLINE, EMBASE, Web of Science and Scopus were systematically searched before March 2018. Human studies that compared the composition of gut microbiota in ASD patients and HCs using culture-independent techniques were included. Independent data extraction and quality assessment of studies were conducted according to PRISMA statement and Newcastle-Ottawa Scale. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to infer biological functional changes of the shifted microbiota with the available data in four studies. Sixteen studies with a total sample size of 381 ASD patients and 283 HCs were included in this systematic review. The quality of the studies was evaluated as medium to high. The overall changing of gut bacterial community in terms of β-diversity was consistently observed in ASD patients compared with HCs. Furthermore, Bifidobacterium, Blautia, Dialister, Prevotella, Veillonella, and Turicibacter were consistently decreased, while Lactobacillus, Bacteroides, Desulfovibrio, and Clostridium were increased in patients with ASD relative to HCs in certain studies. This systematic review demonstrated significant alterations of gut microbiota in ASD patients compared with HCs, strengthen the evidence that dysbiosis of gut microbiota may correlate with behavioral abnormality in ASD patients. However, results of inconsistent changing also existed and further big-sampled well-designed studies are needed. Generally, as a potential mediator of risk factors, the gut microbiota could be a novel target for ASD patients in the future.
Topics: Animals; Autism Spectrum Disorder; Dysbiosis; Gastrointestinal Microbiome; Humans
PubMed: 30696816
DOI: 10.1038/s41398-019-0389-6