Gut Failure: A Review of the Pathophysiology and Therapeutic Potentials in the Gut-Heart Axis

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.

Small Intestinal Bacterial Overgrowth in Various Specialties of Medical Practice (Literature Review and Expert Council Resolution)

Aim: to discuss current views on the clinical significance, diagnostic opportunities, and therapeutic approaches in the treatment of small intestinal bacterial overgrowth (SIBO) as an important component in the gut microbiota function assessment, to assess the awareness of physicians and the opportunities in the diagnosis and treatment of this disease in patients in the Federal districts of the Russian Federation, as well as to present the proceedings of the Expert Council held on December 16, 2023 in Moscow.

Key points. SIBO is a common syndrome often associated with irritable bowel syndrome, liver cirrhosis, asthma, and congestive heart failure, being also a predictor of early death in the elderly. Today, in many regions of the Russian Federation, there are limitations for instrumental diagnosis of this disease — lack of awareness among doctors, unavailability of gas analyzers for diagnosing SIBO, lack of information about the need to diagnose SIBO in the standards of compulsory health insurance. Rifaximin is the first-line treatment due to the highest therapeutic efficacy. One of the ways to increase the efficacy of SIBO treatment is to include strain-specific probiotics in the treatment regimen. Saccharomyces boulardii CNCM I-745 is thought to be the most studied, promising probiotic. The review also presents statistical data on the issues in the diagnosis and treatment of SIBO in the regions of the Russian Federation.

Conclusion. Optimization of approaches to the diagnosis and treatment of SIBO, the development of domestic gas analyzers, increasing the awareness of physicians in all regions of the Russian Federation, as well as the development and optimization of clinical recommendations appear to be necessary measures to increase the effectiveness of medical care, the duration and quality of life of the Russian population. These goals can be achieved within the framework of Federal programs under the supervision of specialized reference centers of the Ministry of Health of the Russian Federation.

Unveiling the relationship between gut microbiota and heart failure: Recent understandings and insights

Gut microbiota, which comprises a broad range of bacteria inhabiting the human intestines, plays a crucial role in establishing a mutually beneficial relationship with the host body. Dysbiosis refers to the perturbations in the composition or functioning of the microbial community, which can result in a shift from a balanced microbiota to an impaired state. This alteration has the potential to contribute to the development of chronic systemic inflammation. Heart failure (HF) is a largely prevalent clinical condition that has been demonstrated to have variations in the gut microbiome, indicating a potential active involvement in the pathogenesis and advancement of the disease. The exploration of the complex interplay between the gut microbiome and HF presents a potential avenue for the discovery of innovative biomarkers, preventive measures, and therapeutic targets. This review aims to investigate the impact of gut bacteria on HF.

Role of Intestinal Inflammation and Permeability in Patients with Acute Heart Failure

Background and Objectives: Heart failure (HF) represents a major health burden. Although several treatment regimens are available, their effectiveness is often unsatisfactory. Growing evidence suggests a pivotal role of the gut in HF. Our study evaluated the prognostic role of intestinal inflammation and permeability in older patients with acute HF (AHF), and their correlation with the common parameters traditionally used in the diagnostic-therapeutic management of HF. Materials and Methods: In a single-center observational, prospective, longitudinal study, we enrolled 59 patients admitted to the Emergency Department (ED) and then hospitalized with a diagnosis of AHF, from April 2022 to April 2023. Serum routine laboratory parameters and transthoracic echocardiogram were assayed within the first 48 h of ED admission. Fecal calprotectin (FC) and both serum and fecal levels of zonulin were measured, respectively, as markers of intestinal inflammation and intestinal permeability. The combined clinical outcome included rehospitalizations for AHF and/or death within 90 days. Results: Patients with increased FC values (>50 µg/g) showed significantly worse clinical outcomes (p < 0.001) and higher median levels of NT-proBNP (p < 0.05). No significant correlation was found between the values of fecal and serum zonulin and the clinical outcome. Median values of TAPSE were lower in those patients with higher values of fecal calprotectin (p < 0.05). After multivariate analysis, NT-proBNP and FC values > 50 µg/g resulted as independent predictors of a worse clinical outcome. Conclusions: Our preliminary finding supports the hypothesis of a close relationship between the gut and heart, recognizing in a specific marker of intestinal inflammation such as FC, an independent predictive prognostic role in patients admitted for AHF. Further studies are needed to confirm these results, as well as investigate the reliability of new strategies targeted at modulation of the intestinal inflammatory response, and which are able to significantly impact the course of diseases, mainly in older and frail patients.

Gut Microbiome-Based Therapeutics in Critically Ill Adult Patients-A Narrative Review

The gut microbiota plays a crucial role in the human microenvironment. Dysbiosis of the gut microbiota is a common pathophysiological phenomenon in critically ill patients. Therefore, utilizing intestinal microbiota to prevent complications and improve the prognosis of critically ill patients is a possible therapeutic direction. The gut microbiome-based therapeutics approach focuses on improving intestinal microbiota homeostasis by modulating its diversity, or treating critical illness by altering the metabolites of intestinal microbiota. There is growing evidence that fecal microbiota transplantation (FMT), selective digestive decontamination (SDD), and microbiota-derived therapies are all effective treatments for critical illness. However, different treatments are appropriate for different conditions, and more evidence is needed to support the selection of optimal gut microbiota-related treatments for different diseases. This narrative review summarizes the curative effects and limitations of microbiome-based therapeutics in different critically ill adult patients, aiming to provide possible directions for gut microbiome-based therapeutics for critically ill patients such as ventilator-associated pneumonia, sepsis, acute respiratory distress syndrome, and COVID-19, etc.

The correlation between primary open-angle glaucoma (POAG) and gut microbiota: a pilot study towards predictive, preventive, and personalized medicine

Background

Glaucoma is the leading cause of irreversible blindness worldwide. Emerged evidence has shown that glaucoma is considered an immune system related disorder. The gut is the largest immune organ in the human body and the gut microbiota (GM) plays an irreversible role in maintaining immune homeostasis. But, how the GM influences glaucoma remains unrevealed. This study aimed at investigating the key molecules/pathways mediating the GM and the glaucoma to provide new biomarkers for future predictive, preventive, and personalized medicine.

Methods

Datasets from the primary open-angle glaucoma (POAG) patients (GSE138125) and datasets for target genes of GM/GM metabolites were downloaded from a public database. For GSE138125, the differentially expressed genes (DEGs) between healthy and POAG samples were identified. And the online Venn diagram tool was used to obtain the DEGs from POAG related to GM. After which GM-related DEGs were analyzed by correlation analysis, pathway enrichment analysis, and protein-protein interaction (PPI) network analysis. Human trabecular meshwork cells were used for validation, and the mRNA level of hub genes was verified by quantitative real-time polymerase chain reaction (RT-qPCR) in the in vitro glaucoma model.

Results

A total of 16 GM-related DEGs in POAG were identified from the above 2 datasets (9 upregulated genes and 7 downregulated genes). Pathway enrichment analysis indicated that these genes are mostly enriched in immune regulation especially macrophages-related pathways. Then 6 hub genes were identified by PPI network analysis and construction of key modules. Finally, RT-qPCR confirmed that the expression of the hub genes in the in vitro glaucoma model was consistent with the results of bioinformatics analysis of the mRNA chip.

Conclusion

This bioinformatic study elucidates NFKB1, IL18, KITLG, TLR9, FKBP2, and HDAC4 as hub genes for POAG and GM regulation. Immune response modulated by macrophages plays an important role in POAG and may be potential targets for future predictive, preventive, and personalized diagnosis and treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00336-2.