The gut microbiome in human health and disease-Where are we and where are we going? A bibliometric analysis

Unraveling the gut-brain axis: the impact of steroid hormones and nutrition on Parkinson's disease

This comprehensive review explores the intricate relationship between nutrition, the gut microbiome, steroid hormones, and Parkinson's disease within the context of the gut-brain axis. The gut-brain axis plays a pivotal role in neurodegenerative diseases like Parkinson's disease, encompassing diverse components such as the gut microbiota, immune system, metabolism, and neural pathways. The gut microbiome, profoundly influenced by dietary factors, emerges as a key player. Nutrition during the first 1000 days of life shapes the gut microbiota composition, influencing immune responses and impacting both child development and adult health. High-fat, high-sugar diets can disrupt this delicate balance, contributing to inflammation and immune dysfunction. Exploring nutritional strategies, the Mediterranean diet's anti-inflammatory and antioxidant properties show promise in reducing Parkinson's disease risk. Microbiome-targeted dietary approaches and the ketogenic diet hold the potential in improving brain disorders. Beyond nutrition, emerging research uncovers potential interactions between steroid hormones, nutrition, and Parkinson's disease. Progesterone, with its anti-inflammatory properties and presence in the nervous system, offers a novel option for Parkinson's disease therapy. Its ability to enhance neuroprotection within the enteric nervous system presents exciting prospects. The review addresses the hypothesis that α-synuclein aggregates originate from the gut and may enter the brain via the vagus nerve. Gastrointestinal symptoms preceding motor symptoms support this hypothesis. Dysfunctional gut-brain signaling during gut dysbiosis contributes to inflammation and neurotransmitter imbalances, emphasizing the potential of microbiota-based interventions. In summary, this review uncovers the complex web of interactions between nutrition, the gut microbiome, steroid hormones, and Parkinson's disease within the gut-brain axis framework. Understanding these connections not only offers novel therapeutic insights but also illuminates the origins of neurodegenerative diseases such as Parkinson's disease.

A review of metabolic and microbial influences on women with polycystic ovarian syndrome

INTRODUCTION

Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine and metabolic disorder affecting reproductive-aged women worldwide. Characterized by irregular menstruation, signs of hyperandrogenism, polycystic ovaries via ultrasound ovarian dysfunction.

AREA COVERED

The review delves into the intricate pathophysiological mechanisms underlying the syndrome. Dysregulation of the hypothalamic-pituitary-ovarian axis, IR, obesity, and hyperandrogenism contribute to anovulation and follicular dysfunction which is associated with gut dysbiosis, bile metabolites, and an unhealthy diet. Metabolomics and genomics analyses offer insights into the metabolism of bile acids (BAs) and gut microbiota dysbiosis in PCOS. BAs, crucial for metabolic regulation, are influenced by microbes, impacting hormonal balance. Disruptions in gut microbiota contribute to hormonal dysregulation. Interconnected pathways involving BAs and gut microbiota are pivotal in PCOS. Therapeutic implications include a healthy diet, exercise, and interventions targeting gut microbiota modulation and BAs metabolite to alleviate PCOS symptoms and improve metabolic health.

CONCLUSION

PCOS requires a multifaceted, multidisciplinary approach for effective management, including lifestyle changes, medications, and emerging therapies. Tailored strategies considering individual needs and personalized treatment plans are crucial for successful PCOS management. Despite existing knowledge, comprehensive investigations are needed to bridge research gaps and discern the interconnected pathways linking the development of PCOS and the gut-bile axis which are interconnected with metabolic disorders and the development of PCOS. Gut microbiota and hormonal regulation offer promising avenues for innovative therapeutic strategies aimed at addressing the root causes of PCOS and improving patient outcomes.

Microbiome contributions to pain: a review of the preclinical literature

ABSTRACT

Over the past 2 decades, the microbiome has received increasing attention for the role that it plays in health and disease. Historically, the gut microbiome was of particular interest to pain scientists studying nociplastic visceral pain conditions given the anatomical juxtaposition of these microorganisms and the neuroimmune networks that drive pain in such diseases. More recently, microbiomes both inside and across the surface of the body have been recognized for driving sensory symptoms in a broader set of diseases. Microbiomes have never been a more popular topic in pain research, but to date, there has not been a systematic review of the preclinical microbiome pain literature. In this article, we identified all animal studies in which both the microbiome was manipulated and pain behaviors were measured. Our analysis included 303 unique experiments across 97 articles. Microbiome manipulation methods and behavioral outcomes were recorded for each experiment so that field-wide trends could be quantified and reported. This review specifically details the animal species, injury models, behavior measures, and microbiome manipulations used in preclinical pain research. From this analysis, we were also able to conclude how manipulations of the microbiome alter pain thresholds in naïve animals and persistent pain intensity and duration in cutaneous and visceral pain models. This review summarizes by identifying existing gaps in the literature and providing recommendations for how to best plan, implement, and interpret data collected in preclinical microbiome pain experiments.

Revolutionizing Gastrointestinal Disorder Management: Cutting-Edge Advances and Future Prospects

In recent years, remarkable strides have been made in the management of gastrointestinal disorders, transforming the landscape of patient care and outcomes. This article explores the latest breakthroughs in the field, encompassing innovative diagnostic techniques, personalized treatment approaches, and novel therapeutic interventions. Additionally, this article emphasizes the use of precision medicine tailored to individual genetic and microbiome profiles, and the application of artificial intelligence in disease prediction and monitoring. This review highlights the dynamic progress in managing conditions such as inflammatory bowel disease, gastroesophageal reflux disease, irritable bowel syndrome, and gastrointestinal cancers. By delving into these advancements, we offer a glimpse into the promising future of gastroenterology, where multidisciplinary collaborations and cutting-edge technologies converge to provide more effective, patient-centric solutions for individuals grappling with gastrointestinal disorders.

Two cosmoses, one universe: a narrative review exploring the gut microbiome's role in the effect of urban risk factors on vascular ageing

In the face of rising global urbanisation, understanding how the associated environment and lifestyle impact public health is a cornerstone for prevention, research, and clinical practice. Cardiovascular disease is the leading cause of morbidity and mortality worldwide, with urban risk factors contributing greatly to its burden. The current narrative review adopts an exposome approach to explore the effect of urban-associated physical-chemical factors (such as air pollution) and lifestyle on cardiovascular health and ageing. In addition, we provide new insights into how these urban-related factors alter the gut microbiome, which has been associated with an increased risk of cardiovascular disease. We focus on vascular ageing, before disease onset, to promote preventative research and practice. We also discuss how urban ecosystems and social factors may interact with these pathways and provide suggestions for future research, precision prevention and management of vascular ageing. Most importantly, future research and decision-making would benefit from adopting an exposome approach and acknowledging the diverse and boundless universe of the microbiome.

Lycium barbarum polysaccharide remodels colon inflammatory microenvironment and improves gut health

Aim

Disturbed intestinal microbiota has been implicated in the inflammatory microenvironment of the colon, which usually results in ulcerative colitis (UC). Given the limitations of these drugs, it is important to explore alternative means of protecting the gut health from UC. This study aimed to investigate the potential of polysaccharides as beneficial nutrients in the regulation of the gut microbiota, which determines the inflammatory microenvironment of the colon.

Materials and methods

Mice were treated with dextran sulfate sodium (DSS) to evaluate the effects and mechanisms of Lycium barbarum polysaccharide (LBP) in remodeling the inflammatory microenvironment and improving gut health. Body weight and disease activity indices were monitored daily. Hematoxylin and eosin staining was used to analyze colon dynamics. The levels of inflammatory indicators and expression of MUC-2, claudin-1, ZO-1, and G-protein-coupled receptor 5 (TGR5) were determined using assay kits and immunohistochemistry, respectively. 16S rRNA high-throughput sequencing of the intestinal microbiota and liquid chromatography-tandem mass spectrometry for related bile acids were used.

Results

LBP significantly improved the colonic tissue structure by upregulating MUC-2, claudin-1, and ZO-1 protein expression. The bacterial genus Dubosiella was dominant in healthy mice, but significantly decreased in mice treated with DSS. LBP rehabilitated Dubosiella in the sick guts of DSS mice to a level close to that of healthy mice. The levels of other beneficial bacterial genera Akkermansia and Bifidobacterium were also increased, whereas those of the harmful bacterial genera Turicibacter, Clostridium_sensu_stricto_1, Escherichia-Shigella, and Faecalibaculum decreased. The activity of beneficial bacteria promoted the bile acids lithocholic and deoxycholic acids in mice with UC, which improved the gut barrier function through the upregulation of TGR5.

Conclusion

The inflammatory microenvironment in the gut is determined by the balance of the gut microbiota. LBP showed great potential as a beneficial nutrient for rehabilitating Dubosiella which is dominant in the gut of healthy mice. Nutrient-related LBP may play an important role in gut health management.

Trends in gut-heart axis and heart failure research (1993-2023): A bibliometric and visual analysis

Background

The incidence of heart failure, the terminal stage of several cardiovascular diseases, is increasing owing to population growth and aging. Bidirectional crosstalk between the gut and heart plays a significant role in heart failure. This study aimed to analyze the gut-heart axis and heart failure from a bibliometric perspective.

Methods

We extracted literature regarding the gut-heart axis and heart failure from the Web of Science Core Collection database (January 1, 1993, to June 30, 2023) and conducted bibliometric and visualization analyses using Microsoft Excel, CiteSpace, VOSviewer, and the R package "bibliometrix."

Results

The final analysis included 1646 articles with an average of 35.38 citations per article. Despite some fluctuations, the number of articles published per year has steadily increased over the past 31 years, particularly since 2018. A total of 9412 authors from 2287 institutions in 86 countries have contributed to this field. The USA and China have been the most productive countries, with the Cleveland Clinic in the USA and Charité-Universitätsmedizin Berlin in Germany being the most active institutions. The cooperation between countries/regions and institutions was relatively close. Professor Tang WHW was the most productive author in the field and the journal Shocks published the highest number of articles. "Heart failure," "gut microbiota," "trimethylamine N-oxide," and "inflammation" were the most common keywords, representing the current research hotspots. The keyword burst analysis indicated that "gut microbiota" and "short-chain fatty acids" are the current frontier research topics in this field.

Conclusion

Research on the gut-heart axis and heart failure is increasing. This bibliometric analysis indicated that the mechanisms associated with the gut-heart axis and heart failure, particularly the gut microbiota, trimethylamine N-oxide, inflammation, and short-chain fatty acids, will become hotspots and emerging trends in research in this field. These findings provide valuable insights into current research and future directions.

Bacteriophages, gut bacteria, and microbial pathways interplay in cardiometabolic health

Cardiometabolic diseases are leading causes of mortality in Western countries. Well-established risk factors include host genetics, lifestyle, diet, and the gut microbiome. Moreover, gut bacterial communities and their activities can be altered by bacteriophages (also known simply as phages), bacteria-infecting viruses, making these biological entities key regulators of human cardiometabolic health. The manipulation of bacterial populations by phages enables the possibility of using phages in the treatment of cardiometabolic diseases through phage therapy and fecal viral transplants. First, however, a deeper understanding of the role of the phageome in cardiometabolic diseases is required. In this review, we first introduce the phageome as a component of the gut microbiome and discuss fecal viral transplants and phage therapy in relation to cardiometabolic diseases. We then summarize the current state of phageome research in cardiometabolic diseases and propose how the phageome might indirectly influence cardiometabolic health through gut bacteria and their metabolites.

Exploring the Perspective of Oral Microbiome Studies in PubMed Database: A Bibliometric Appraisal

This research aims to postulate an exhaustive sketch of the current research background on the oral microbiome to emphasize prevailing research trends. On November 25, 2023, a digital exploration was conducted on the PubMed platform. The search strategy employed was- '(Microbiome, Microbiota, Microorganisms, Bacteria, Virus, Fungi) AND (Oral, Dental, Saliva, Plaque, Gingival Crevicular Fluid)'. Inclusive criteria comprised review articles, clinical trials, and meta-analyses. The Biblioshiny app and VOSviewer software were used to create and visualize bibliometric maps for network, thematic, and factorial analyses. The PubMed database search unveiled 215,068 published research studies on the oral microbiome, indicating a fluctuating publication pattern with an all-embracing mounting trajectory. Notably, there was a substantial increase in publications in 2020 and 2021, succeeded by a marked decline in 2022 and 2023. Sichuan University and the International Journal of Molecular Sciences emerged as the most prolific contributors among organizations and relevant sources. Keyword analysis revealed a research emphasis on the COVID-19 pandemic and the SARS-CoV-2 virus since 2019. Thematic mapping categorized key terms into motor, primary, niche, and emerging themes. The emerging terms identified are viral immunogenicity, antibodies, and vaccines, which support the revelation that COVID-19 and related terms will be the most pertinent subjects in oral microbiome studies in the future. Factorial analysis delineated the relationships between topics and subtopics in this domain.

End-to-end donor screening and manufacturing controls: complementary quality-based strategies to minimize patient risk for donor-derived microbiome therapeutics

Advances in microbiome therapeutics have been motivated by a deeper understanding of the role that the gastrointestinal microbiome plays in human health and disease. The FDA approval of two stool-derived live biotherapeutic products (LBPs), REBYOTA® 150 mL enema (fecal microbiota, live-jslm; formerly RBX2660) and VOWST® oral capsules (fecal microbiota spores, live-brpk; formerly SER-109), for the prevention of recurrent CDI in adults following antibiotic treatment for recurrent CDI provides promise and insights for the development of LBPs for other diseases associated with microbiome dysfunction. Donor-derived products carry risk of disease transmission that must be mitigated through a robust donor screening program and downstream manufacturing controls. Most published recommendations for donor screening practices are prescriptive and do not include a systematic, risk-based approach for donor stool-derived products. A general framework for an end-to-end donor screening program is needed using risk management strategies for donor-derived microbiome therapeutic using a matrixed approach, combining the elements of donor screening with manufacturing controls that are designed to minimize risk to patients. A donor screening paradigm that incorporates medical history, physical examination, laboratory testing, and donor sample inspection are only the first steps in reducing risk of transmission of infectious agents. Manufacturing controls are the cornerstone of risk mitigation when screening unwittingly fails. Failure Mode and Effects Analysis (FMEA) can be used as a tool to assess for residual risk that requires further donor or manufacturing controls. Together, a well-reasoned donor program and manufacturing controls are complementary strategies that must be revisited and reexamined frequently with constant vigilance to mitigate risk to patients. In the spirit of full disclosure and informed consent, physicians should discuss any limitations in the donor screening and manufacturing processes with their patients prior to treatment with microbiome-based therapeutics.

Akkermansia muciniphila - A Potential Next-generation Probiotic for Non-alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver conditions, and its growing prevalence is a serious concern worldwide, especially in Western countries. Researchers have pointed out several genetic mutations associated with NAFLD; however, the imbalance of the gut microbial community also plays a critical role in the progression of NAFLD. Due to the lack of approved medicine, probiotics gain special attention in controlling metabolic disorders like NAFLD. Among these probiotics, Akkermansia muciniphila (a member of natural gut microflora) is considered one of the most efficient and important bacterium in maintaining gut health, energy homeostasis, and lipid metabolism. In this perspective, we discussed the probable molecular mechanism of A. muciniphila in controlling the progression of NAFLD and restoring liver health. The therapeutic potential of A. muciniphila in NAFLD has been tested primarily on animal models, and thus, more randomized human trials should be conducted to prove its efficacy.

Rheumatic diseases and gut microbiota publications in 2002-2022: a Scopus‑based bibliometric analysis

Rheumatic diseases (RDs) include a variety of autoimmune disorders defined by severe inflammation, primarily affecting the joints, tendons, ligaments, bones, and muscles. Recent research has revealed the association between rheumatic diseases and gut microbiota, thereby providing insights into the underlying mechanisms of disease pathogenesis. The objective of this study was to evaluate the quantity and quality of scientific research regarding the association between RDs and gut microbiota, as well as to elucidate the characteristics of worldwide research output in this field. The present bibliometric analysis was carried out using the Scopus database, using the keywords "rheumatology," "arthritis," and "gut microbiota." The study involved determining the number of articles, the number of active countries with journals, the identification of prolific authors, and the collection of citation data. Additionally, analyses of trends were conducted. 503 articles in all were reviewed. Collaboration networks were visualized using mapping techniques. The number of articles on RDs and gut microbiota exhibited a consistent pattern from 2002 to 2022 (p < 0.05). The five most productive countries were China (n = 128; 25.45%), the United States (n = 101; 20.07%), Italy (n = 40; 7.95%), the United Kingdom (n = 20; 3.98%), and Japan (n = 17; 3.38%). Israel, Italy, Belgium, and Portugal had the highest values regarding the number of articles per million population. Australia, Canada, and the United Kingdom were the top three countries regarding average citation count. This bibliometric analysis evaluates and synthesizes global scientific output on RDs and gut microbiota. The literature on the association between rheumatic diseases and gut microbiota is growing. Supporting researchers in countries with limited involvement in this field will contribute to its growth.

Comparison of four DNA extraction methods for 16s rRNA microbiota profiling of human faecal samples

OBJECTIVE

Growth in large population-based studies assessing contributions of the gut microbiota to health and disease requires high-throughput sample processing and analysis methods. This study assessed the impact that modifications to a commercially available magnetic bead based, semi-automated DNA extraction kit had on determination of microbial composition, relative to an established in-house method involving a combination of mechanical and chemical lysis. DNA was extracted from faecal samples from healthy adults (n = 12; 34-69 years), microbial composition was determined by V3-V4 16s rRNA sequencing and compared between extraction methods.

RESULTS

Diversity metrics did not differ between extraction methods. Differences in the relative abundance of key phyla, including a significantly lower abundance of the Firmicutes (p = 0.004) and higher relative abundance of the Bacteroidetes (p = 0.005) and Proteobacteria (p = 0.008) phyla were noted where the DNA extraction did not include additional chemical and mechanical lysis. Principal coordinate analysis of family and genera level data also suggested a potential for sample pre-processing to impact microbial composition. Observations of the potential for skewed microbial composition profiles from samples prepared using a semi-automated DNA extraction kit without additional sample pre-processing highlights a need for consideration of standardisation of methodological approaches to increase the comparability of microbial compositional data.

Homo sapiens—A Species Not Designed for Space Flight: Health Risks in Low Earth Orbit and Beyond, Including Potential Risks When Traveling beyond the Geomagnetic Field of Earth

Homo sapiens and their predecessors evolved in the context of the boundary conditions of Earth, including a 1 g gravity and a geomagnetic field (GMF). These variables, plus others, led to complex organisms that evolved under a defined set of conditions and define how humans will respond to space flight, a circumstance that could not have been anticipated by evolution. Over the past ~60 years, space flight and living in low Earth orbit (LEO) have revealed that astronauts are impacted to varying degrees by such new environments. In addition, it has been noted that astronauts are quite heterogeneous in their response patterns, indicating that such variation is either silent if one remained on Earth, or the heterogeneity unknowingly contributes to disease development during aging or in response to insults. With the planned mission to deep space, humans will now be exposed to further risks from radiation when traveling beyond the influence of the GMF, as well as other potential risks that are associated with the actual loss of the GMF on the astronauts, their microbiomes, and growing food sources. Experimental studies with model systems have revealed that hypogravity conditions can influence a variety biological and physiological systems, and thus the loss of the GMF may have unanticipated consequences to astronauts’ systems, such as those that are electrical in nature (i.e., the cardiovascular system and central neural systems). As astronauts have been shown to be heterogeneous in their responses to LEO, they may require personalized countermeasures, while others may not be good candidates for deep-space missions if effective countermeasures cannot be developed for long-duration missions. This review will discuss several of the physiological and neural systems that are affected and how the emerging variables may influence astronaut health and functioning.