Bibliometric and Visual Analysis of Research on the Links Between the Gut Microbiota and Depression From 1999 to 2019

Abstract

Background: There is a crucial link between the gut microbiota and the host central nervous system, and the communication between them occurs via a bidirectional pathway termed the “microbiota-gut-brain axis.” The gut microbiome in the modern environment has markedly changed in response to environmental factors. These changes may affect a broad range of host psychiatric disorders, such as depression, by interacting with the host through metabolic, immune, neural, and endocrine pathways. Nevertheless, the general aspects of the links between the gut microbiota and depression have not been systematically investigated through bibliometric analysis.Aim: This study aimed to analyze the current status and developing trends in gut microbiota research in the depression field through bibliometric and visual analysis.Methods: A total of 1,962 publications published between 1999 and 2019 were retrieved from the Web of Science Core Collection. CiteSpace (5.6 R5) was used to perform collaboration network analysis, co-citation analysis, co-occurrence analysis, and citation burst detection.Results: The number of publications has been rapidly growing since 2010. The collaboration network analysis revealed that the USA, University College Cork, and John F. Cryan were the most influential country, institute, and scholar, respectively. The most productive and co-cited journals were Brain Behavior and Immunity and Proceedings of the National Academy of Sciences of the United States of America, respectively. The co-citation analysis of references revealed that the most recent research focus was in the largest theme cluster, “cytokines,” thus reflecting the important research foundation in this field. The co-occurrence analysis of keywords revealed that “fecal microbiota” and “microbiome” have become the top two research hotspots since 2013. The citation burst detection for keywords identified several keywords, including “Parkinson's disease,” “microbiota-gut-brain axis,” “microbiome,” “dysbiosis,” “bipolar disorder,” “impact,” “C reactive protein,” and “immune system,” as new research frontiers, which have currently ongoing bursts.Conclusions: These results provide an instructive perspective on the current research and future directions in the study of the links between the gut microbiota and depression, which may help researchers choose suitable cooperators or journals, and promote their research illustrating the underlying molecular mechanisms of depression, including its etiology, prevention, and treatment.

Bibliometrics and Visual Analysis of the Research Status and Trends of Postpartum Depression From 2000 to 2020

“…A review of bibliometrics articles related to depression reveals that researchers are paying more and more attention to psychological research as time goes by, such as the comorbidity of pain and depression (Wang et al, 2019 ), the links between the gut microbiota and depression (Zhu et al, 2020 ). However, there are few bibliometric studies on women's mental disorders (García-García et al, 2005 ; López-Muñoz et al, 2008 ), and almost no attention has been paid to the current research direction and hotspot of postpartum depression.…”

Comprehensive Bibliometric Analysis of the Kynurenine Pathway in Mood Disorders: Focus on Gut Microbiota Research

“…Interestingly, active collaborative relationships between Thailand and countries such as Australia, the United Kingdom, and Bulgaria were also observed and were likely to be associated with the influential expert, Author “B” from Chulalongkorn University, who has a history of close long-term cooperation with researchers (e.g., Authors “E” and “J”) from Deakin University (Australia), CRC Scotland and London (United Kingdom), Medical University of Plovdiv (Bulgaria), Federal University of Ceará (Brazil), and University of Toronto (Canada). Among the top ten active researchers in the field of the KP in mood disorders, Authors “B,” “E,” and “J” were also among the top ten most prolific authors in the gut microbiota research in the depression field, according to our previous published bibliometric analysis ( Zhu et al, 2021 ).…”

“…A comprehensive search was conducted on two large, multidisciplinary citation databases, Scopus and Web of Science Core Collection (WoSCC) ( Falagas et al, 2008 ), on a single day (January 1, 2021), to avoid the discrepancies due to daily database updates. These databases were chosen because Scopus is the world’s largest abstract and citation database ( Zyoud et al, 2019 ), and WoSCC is a curated collection of high-quality scholarly peer-reviewed literature published worldwide ( Zhu et al, 2021 ). The search phrases associated with the KP included KYN and its key metabolites (e.g., KYNA, QUIN, 3-HK, and 3-HAA) ( Figure 3A ), and the phrases associated with mood disorders included depression and related disorders such as BD.…”

“…Notably, the findings from Bravo et al (2011) demonstrated the potential ability of probiotics to regulate emotional behavior and central gamma-aminobutyric acid receptor expression via the vagus nerve, thus highlighting the important role of bacteria in bidirectional gut-brain interactions. The further development of culture-independent molecular methods, such as 16S ribosomal RNA and metagenomic sequencing tools, has enabled researchers to better understand the structure and functions of the gut microbiome, thereby contributing to a key research hotspot, “gut microbiota,” occurring in 2011 ( Zhu et al, 2021 ).…”

“…Thus, researchers may have difficulty in attaining a comprehensive and macroscopic view of this field, because of the diverse research domains ( Chen et al, 2020 ). Furthermore, additional innovations and breakthroughs might be hindered, owing to potential untimely analysis of research frontiers ( Zhu et al, 2021 ). The present bibliometric analysis fills the gap in the literature in this field.…”