Bacteria present in carotid arterial plaques are found as biofilm deposits which may contribute to enhanced risk of plaque rupture

Gut Microbiota and Metabolic Syndrome: Relationships and Opportunities for New Therapeutic Strategies

Since its discovery, numerous studies have shown the role of the microbiota in well-being and disease. The gut microbiota represents an essential factor that plays a multidirectional role that affects not just the gut but also other parts of the body, including the brain, endocrine system, humoral system, immune system, and metabolic pathways, as well as host-microbiome interactions. Through a comprehensive analysis of existing literature using the desktop research methodology, this review elucidates the mechanisms by which gut microbiota dysbiosis contributes to metabolic dysfunction, including obesity, dyslipidaemia, hypertension, atherosclerosis, hyperuricemia, and hyperglycaemia. Furthermore, it examines the bidirectional communication pathways between gut microbiota and host metabolism, highlighting the role of microbial-derived metabolites, immune modulation, and gut barrier integrity in shaping metabolic homeostasis. Importantly, the review identifies promising therapeutic strategies targeting the gut microbiota as potential interventions for metabolic syndrome, including probiotics, prebiotics, symbiotics, dietary modifications, and faecal microbiota transplantation. By delineating the bidirectional interactions between gut microbiota and metabolic syndrome, the review not only advances our understanding of disease pathophysiology but also underscores the potential for innovative microbiota-based interventions to mitigate the global burden of metabolic syndrome and its associated complications.

Beyond antibiotics: CRISPR/Cas9 triumph over biofilm-associated antibiotic resistance infections

A complex structure known as a biofilm is formed when a variety of bacterial colonies or a single type of cell in a group sticks to a surface. The extracellular polymeric compounds that encase these cells, often consisting of proteins, eDNA, and polysaccharides, exhibit strong antibiotic resistance. Concerns about biofilm in the pharmaceutical industry, public health, and medical fields have sparked a lot of interest, as antibiotic resistance is a unique capacity exhibited by these biofilm-producing bacteria, which increases morbidity and death. Biofilm formation is a complicated process that is controlled by several variables. Insights into the processes to target for the therapy have been gained from multiple attempts to dissect the biofilm formation process. Targeting pathogens within a biofilm is profitable because the bacterial pathogens become considerably more resistant to drugs in the biofilm state. Although biofilm-mediated infections can be lessened using the currently available medications, there has been a lot of focus on the development of new approaches, such as bioinformatics tools, for both treating and preventing the production of biofilms. Technologies such as transcriptomics, metabolomics, nanotherapeutics and proteomics are also used to develop novel anti-biofilm agents. These techniques help to identify small compounds that can be used to inhibit important biofilm regulators. The field of appropriate control strategies to avoid biofilm formation is expanding quickly because of this spurred study. As a result, the current article addresses our current knowledge of how biofilms form, the mechanisms by which bacteria in biofilms resist antibiotics, and cutting-edge treatment approaches for infections caused by biofilms. Furthermore, we have showcased current ongoing research utilizing the CRISPR/Cas9 gene editing system to combat bacterial biofilm infections, particularly those brought on by lethal drug-resistant pathogens, concluded the article with a novel hypothesis and aspirations, and acknowledged certain limitations.

Microbiome interactions with different risk factors in development of myocardial infarction

Among all non-communicable diseases, Cardiovascular Diseases (CVDs) stand as the leading global cause of mortality. Within this spectrum, Myocardial Infarction (MI) strikingly accounts for over 15 % of all deaths. The intricate web of risk factors for MI, comprising family history, tobacco use, oral health, hypertension, nutritional pattern, and microbial infections, is firmly influenced by the human gut and oral microbiota, their diversity, richness, and dysbiosis, along with their respective metabolites. Host genetic factors, especially allelic variations in signaling and inflammatory markers, greatly affect the progression or severity of the disease. Despite the established significance of the human microbiome-nutrient-metabolite interplay in associations with CVDs, the unexplored terrain of the gut-heart-oral axis has risen as a critical knowledge gap. Moreover, the pivotal role of the microbiome and the complex interplay with host genetics, compounded by age-related changes, emerges as an area of vital importance in the development of MI. In addition, a distinctive disease susceptibility and severity influenced by gender-based or ancestral differences, adds a crucial insights to the association with increased mortality. Here, we aimed to provide an overview on interactions of microbiome (oral and gut) with major risk factors (tobacco use, alcohol consumption, diet, hypertension host genetics, gender, and aging) in the development of MI and therapeutic regulation.

Helicobacter cinaedi bacterium association with atherosclerosis and other diseases

Helicobacter is a genus of spiral-shaped Gram-negative enterohepatic bacteria whose members are capable of causing bacteremia in humans. One of the poorly studied members of this genus is the bacterium Helicobacter cinaedi. This microorganism was first isolated from human fecal samples in 1984. Although it was long considered to be associated with only immunocompromised patients, more evidence in recent years has implicated H. cinaedi in causing serious pathologies in immunocompetent populations. In addition, H. cinaedi is also reported to be associated with a few chronic or severe illnesses, such as atherosclerosis, which in turn can lead to the development of other cardiovascular pathologies: one of the leading causes of mortality worldwide. Helicobacter cinaedi often goes unnoticed in standard diagnostic methods due to its slow growth under microaerobic conditions. This often leads to significant underdetection and hence undermines the role of this bacterium in the pathogenesis of various diseases and the extent of its spread in humans. In this review, we have compiled information on pathologies associated with H. cinaedi, the occurrence of the bacterium in humans and animals, and the latest developments in diagnosing the bacterium and treating associated diseases.

Enterobacterales Biofilm-Specific Genes and Antimicrobial and Anti-Inflammatory Biomarkers in the Blood of Patients with Ischemic Heart Disease

BACKGROUND

Ischemic heart disease (IHD) is the most prevalent type of cardiovascular disease. The main cause of IHD is atherosclerosis, which is a multifactorial inflammatory disease of blood vessels. Studies show that bacteria might have a significant impact on the pathogenesis of atherosclerosis and plaque rupture. This study aimed to evaluate the complexity of interactions between bacteria and the human body concerning metabolites and bacterial genes in patients with ischemic heart disease.

METHODS

Bacterial 16S rDNA and wcaF, papC, and sdhC genes were detected in whole blood using a real-time PCR methodology. An enzyme-linked immunosorbent assay was used to measure the concentration of the LL-37 protein. An analysis of ARA in blood plasma was performed.

RESULTS

Bacterial 16S rDNA was detected in 31% of the study patients, and the genes wcaF and sdhC in 20%. Enterobacterales genes were detected more frequently in patients younger than 65 years than in patients aged 65 years and older (p = 0.018) and in patients with type 2 diabetes (p = 0.048). Concentrations of the human antimicrobial peptide LL-37 and 12S-HETE concentrations were determined to be higher if patients had 16S rDNA and biofilm-specific genes.

CONCLUSIONS

The results of this study enhance the understanding that Enterobacterales bacteria may participate in the pathogenesis of atherosclerosis and IHD. Bacterial DNA and host metabolites in higher concentrations appear to be detected.

Flagellar hook protein FlgE promotes macrophage activation and atherosclerosis by targeting ATP5B

BACKGROUND AND AIMS

Pseudomonas aeruginosa (P. aeruginosa) infections are strongly linked to the development of cardiovascular disease and atherosclerosis; however, the underlying mechanisms remain unclear. We previously confirmed that the flagellar hook protein FlgE in P. aeruginosa has immunostimulatory effects. This study investigated the effects and mechanisms of action of FlgE on atherogenesis.

METHODS

ApoE-/- mice were intravenously challenged with FlgE or FlgEM recombinant proteins for eight weeks. A murine model of chronic lung colonization was established using beads containing either mutable- or wild-type bacteria. Aortic sinus sections were stained to assess atherosclerosis progression. THP-1 macrophages exposed to FlgE or FlgEM were evaluated for their effects on lipid uptake and inflammation in vitro. Western blotting and pull-down assays were used to identify the binding proteins and signaling pathways involved, and specific blocking experiments were performed to confirm these effects.

RESULTS

FlgE accelerated atherosclerosis progression by triggering lipid deposition and inflammatory responses in high-fat diet (HFD)-fed ApoE-/- mice. In comparison to infection with wild-type PAO1, infection with PAO1/flgEΔBmF resulted in reduced atherosclerosis. Mechanistic analysis indicated that FlgE exacerbated lipoprotein uptake and foam cell formation by upregulating SR-A1 expression. Moreover, FlgE activated NF-κB and MAPK signaling, which subsequently led to inflammatory responses in THP-1-derived macrophages. Pull-down assays revealed that FlgE directly interacted with ATP5B, whereas blocking ATP5B attenuated FlgE-induced responses in macrophages.

CONCLUSIONS

FlgE induces macrophage lipid uptake and pro-inflammatory responses mediated by ATP5B/NF-kB/AP-1 signaling, which eventually results in atherosclerosis. These findings support the development of therapeutic strategies for P. aeruginosa infection-induced atherosclerosis.

Detecting prokaryote-specific gene and other bacterial signatures in thrombi from patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Microbial infection has been associated with thrombogenesis. This study aimed to detect bacterium-specific genes and other signatures in thrombi from patients with acute ischemic stroke and to relate these signatures to clinical characteristics.

METHODS

Blood samples were collected before thrombectomy procedures, and thrombus samples were obtained during the procedure. Identification and classification of bacteria in the samples were accomplished using 16 S rRNA gene sequencing. Bacterium-specific structures were observed with transmission electron microscopy. Bacterium-specific biomarkers were detected through immunohistochemical staining.

RESULTS

16 S rRNA gene was detected in 32.1% of the thrombus samples from 81 patients. Bacillus (0.04% vs. 0.00046%, p = 0.003), Parabacteroides (0.20% vs. 0.09%, p = 0.029), Prevotella (1.57% vs. 0.38%, p = 0.010), Streptococcus (1.53% vs. 0.29%, p = 0.001), Romboutsia (0.18% vs. 0.0070%, p = 0.029), Corynebacterium (1.61% vs. 1.26%, p = 0.026) and Roseburia (0.53% vs. 0.05%, p = 0.005) exhibited significantly higher abundance in thrombi compared to arterial blood. Bacteria-like structures were observed in 22 (27.1%), while whole bacteria-like structures were observed in 7 (8.6%) thrombi under transmission electron microscopy. Immunohistochemical staining detected bacterium-specific monocyte/macrophage markers in 51 (63.0%) out of 81 thrombi. Logistic regression analysis indicated that alcohol consumption was associated with a higher bacteria burden in thrombi (odds ratio = 3.19; 95% CI, 1.10-9.27; p = 0.033).

CONCLUSION

Bacterial signatures usually found in the oral cavity and digestive tract were detected in thrombi from patients with ischemic stroke. This suggests a potential involvement of bacterial infection in the development of thrombosis. Long-term alcohol consumption may potentially enhance this possibility.

Relationship between TyG index and the degree of coronary artery lesions in patients with H-type hypertension

BACKGROUND

The TyG index, a prominent metric for assessing insulin resistance, has gained traction as a prognostic tool for cardiovascular disease. Nevertheless, the understanding of the prognostic significance of the extent of coronary artery stenosis in individuals afflicted with H-type hypertension remains limited.

METHODS

A retrospective study was conducted at Wuhan Third Hospital, including a cohort of 320 inpatients who were diagnosed with hypertension in combination with coronary artery disease. The study period spanned from January 1, 2021, to February 1, 2023. The study cohort was stratified based on the severity of stenosis into three distinct groups: low stenosis, medium stenosis, and high stenosis, as determined by the Gensini score derived from coronary angiography findings. The present study aimed to investigate the association between the severity of coronary stenosis and the number of lesion branches, utilizing the TyG index as a testing indicator. The predictive ability of TyG for coronary lesion severity was assessed using logistic regression analysis.

RESULTS

The results of our study indicate a positive correlation between elevated levels of TyG and an increased susceptibility to severe stenosis in individuals diagnosed with H-type hypertension. Upon careful consideration of potential confounding variables, it has been observed that the TyG index exhibits a robust association with the likelihood of severe stenosis in individuals with H-type hypertension (odds ratio [OR] = 4000, 95% confidence interval CI 2.411-6.635, p = 0.0001), as well as the prevalence of multivessel disease (OR = 1.862, 95% CI 1.036-3.348, p < 0.0001). The TyG index demonstrated superior predictive ability for severe coronary stenosis in patients with H-type hypertension compared to those without H-type hypertension (area under the curve [AUC] = 0.888, 95% confidence interval CI 0.838-0.939, p < 0.0001, versus AUC = 0.615, 95% CI 0.494-0.737, p < 0.05).

CONCLUSION

The TyG index is an independent risk factor for the degree of coronary stenosis and a better predictor in patients with H-type hypertension combined with coronary artery disease.

Characteristics of the gut microbiota of patients with symptomatic carotid atherosclerotic plaques positive for bacterial genetic material

Background

The gut microbiota (GM) is believed to be closely associated with symptomatic carotid atherosclerosis (SCAS), yet more evidence is needed to substantiate the significant role of GM in SCAS. This study, based on the detection of bacterial DNA in carotid plaques, explores the characteristics of GM in SCAS patients with plaque bacterial genetic material positivity, aiming to provide a reference for subsequent research.

Methods

We enrolled 27 healthy individuals (NHF group) and 23 SCAS patients (PFBS group). We utilized 16S rDNA V3-V4 region gene sequencing to analyze the microbiota in fecal samples from both groups, as well as in plaque samples from the carotid bifurcation extending to the origin of the internal carotid artery in all patients.

Results

Our results indicate significant differences in the gut microbiota (GM) between SCAS patients and healthy individuals. The detection rate of bacterial DNA in plaque samples was approximately 26%. Compared to patients with negative plaques (PRSOPWNP group), those with positive plaques (PRSOPWPP group) exhibited significant alterations in their GM, particularly an upregulation of 11 bacterial genera (such as Klebsiella and Streptococcus) in the gut, which were also present in the plaques. In terms of microbial gene function prediction, pathways such as Fluorobenzoate degradation were significantly upregulated in the GM of patients with positive plaques.

Conclusion

In summary, our study is the first to identify significant alterations in the gut microbiota of patients with positive plaques, providing crucial microbial evidence for further exploration of the pathogenesis of SCAS.

Genetic support of the causal association between gut microbiota and peripheral artery disease: a bidirectional Mendelian randomization study

BACKGROUND

The causal relationship between gut microbiota and peripheral artery disease (PAD) is still not clear. In this research, we employed the Mendelian randomization (MR) technique to explore the potential causal connection between 211 gut microbiota species and PAD. We also investigated whether the causal effects operate in both directions.

METHODS

We used Genome-wide Association Studies (GWAS) summary statistics data from the MiBioGen and FinnGen consortia to conduct a two-sample MR analysis to explore the causal link between gut microbiota and PAD. Sensitivity analysis is conducted to assess the robustness of the MR results. In addition to that, reverse MR analysis was performed to examine the inverse causal relationship.

RESULTS

The inverse variance weighted (IVW) method provided evidence supporting a causal relationship between 9 specific gut microbiota taxa and PAD. The study findings indicated that family Family XI (OR=1.11, CI 1.00-1.24, P=0.048), genus Lachnoclostridium (OR=1.24, 1.02-1.50, P=0.033), and genus Lachnospiraceae UCG001 (OR=1.17, 1.01-1.35, P=0.031) are risk factors associated with PAD. class Actinobacteria (OR=0.84, 0.72-0.99, P=0.034), family Acidaminococcaceae (OR=0.80, 0.66-0.98, P=0.029), genus Coprococcus2 (OR=0.79, 0.64-0.98, P=0.029), genus Ruminococcaceae UCG004 (OR=0.84, 0.72-0.99, P=0.032), genus Ruminococcaceae UCG010 (OR=0.74, 0.58-0.96, P=0.022), and order NB1n (OR=0.88, 0.79-0.98, P=0.02) may be associated with the risk factors of PAD. Moreover, our analysis did not uncover any evidence of a reverse causal relationship between PAD and the nine specific gut microbiota taxa investigated.

CONCLUSIONS

Our MR research has confirmed the potential causal relationship between gut microbiota and PAD while also identifying specific gut bacterial communities associated with PAD.

Biofilms exacerbate atherogenesis through macrophage-induced inflammatory responses in a fibrous plaque microsystem model

BACKGROUND

Microbes have been implicated in atherosclerosis development and progression, but the impact of bacterial-based biofilms on fibrous plaque rupture remains poorly understood.

RESULTS

Here, we developed a comprehensive atherosclerotic model to reflect the progression of fibrous plaque under biofilm-induced inflammation (FP-I). High expressions of biofilm-specific biomarkers algD, pelA and pslB validated the presence of biofilms. Biofilm promotes the polarization of macrophages towards a pro-inflammatory (M1) phenotype, as demonstrated by an increase in M1 macrophage-specific marker CD80 expression in CD68+ macrophages. The increase in the number of intracellular lipid droplets (LDs) and foam cell percentage highlighted the potential role of biofilms on lipid synthesis or metabolic pathways in macrophage-derived foam cells. In addition, collagen I production by myofibroblasts associated with the fibrous cap was significantly reduced along with the promotion of apoptosis of myofibroblasts, indicating that biofilms affect the structural integrity of the fibrous cap and potentially undermine its strength.

CONCLUSION

We validated the unique role of biofilm-based inflammation in exacerbating fibrous plaque damage in the FP-I model, increasing fibrous plaque instability and risk of thrombosis. Our results lay the foundation for mechanistic studies of the role of biofilms in fibrous plaques, allowing the evaluation of preclinical combination strategies for drug therapy.

STATEMENT OF SIGNIFICANCE

A microsystem-based model was developed to reveal interactions in fibrous plaque during biofilm-induced inflammation (FP-I). Real-time assessment of biofilm formation and its role in fibrous plaque progression was achieved. The presence of biofilms enhanced the expression of pro-inflammatory (M1) specific marker CD80, lipid droplets, and foam cells and reduced anti-inflammatory (M2) specific marker CD206 expression. Fibrous plaque exposure to biofilm-based inflammation reduced collagen I expression and increased apoptosis marker Caspase-3 expression significantly. Overall, we demonstrate the unique role of biofilm-based inflammation in exacerbating fibrous plaque damage in the FP-I model, promoting fibrous plaque instability and enhanced thrombosis risk. Our findings lay the groundwork for mechanistic studies, facilitating the evaluation of preclinical drug combination strategies.

Targeting gut microbiota and immune crosstalk: potential mechanisms of natural products in the treatment of atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory reaction that primarily affects large and medium-sized arteries. It is a major cause of cardiovascular disease and peripheral arterial occlusive disease. The pathogenesis of AS involves specific structural and functional alterations in various populations of vascular cells at different stages of the disease. The immune response is involved throughout the entire developmental stage of AS, and targeting immune cells presents a promising avenue for its treatment. Over the past 2 decades, studies have shown that gut microbiota (GM) and its metabolites, such as trimethylamine-N-oxide, have a significant impact on the progression of AS. Interestingly, it has also been reported that there are complex mechanisms of action between GM and their metabolites, immune responses, and natural products that can have an impact on AS. GM and its metabolites regulate the functional expression of immune cells and have potential impacts on AS. Natural products have a wide range of health properties, and researchers are increasingly focusing on their role in AS. Now, there is compelling evidence that natural products provide an alternative approach to improving immune function in the AS microenvironment by modulating the GM. Natural product metabolites such as resveratrol, berberine, curcumin, and quercetin may improve the intestinal microenvironment by modulating the relative abundance of GM, which in turn influences the accumulation of GM metabolites. Natural products can delay the progression of AS by regulating the metabolism of GM, inhibiting the migration of monocytes and macrophages, promoting the polarization of the M2 phenotype of macrophages, down-regulating the level of inflammatory factors, regulating the balance of Treg/Th17, and inhibiting the formation of foam cells. Based on the above, we describe recent advances in the use of natural products that target GM and immune cells crosstalk to treat AS, which may bring some insights to guide the treatment of AS.

Bacterial biofilms in the human body: prevalence and impacts on health and disease

Bacterial biofilms can be found in most environments on our planet, and the human body is no exception. Consisting of microbial cells encased in a matrix of extracellular polymers, biofilms enable bacteria to sequester themselves in favorable niches, while also increasing their ability to resist numerous stresses and survive under hostile circumstances. In recent decades, biofilms have increasingly been recognized as a major contributor to the pathogenesis of chronic infections. However, biofilms also occur in or on certain tissues in healthy individuals, and their constituent species are not restricted to canonical pathogens. In this review, we discuss the evidence for where, when, and what types of biofilms occur in the human body, as well as the diverse ways in which they can impact host health under homeostatic and dysbiotic states.

Intermittent Fasting and Physical Exercise for Preventing Metabolic Disorders through Interaction with Gut Microbiota: A Review

Metabolic disorders entail both health risks and economic burdens to our society. A considerable part of the cause of metabolic disorders is mediated by the gut microbiota. The gut microbial structure and function are susceptible to dietary patterns and host physiological activities. A sedentary lifestyle accompanied by unhealthy eating habits propels the release of harmful metabolites, which impair the intestinal barrier, thereby triggering a constant change in the immune system and biochemical signals. Noteworthy, healthy dietary interventions, such as intermittent fasting, coupled with regular physical exercise can improve several metabolic and inflammatory parameters, resulting in stronger beneficial actions for metabolic health. In this review, the current progress on how gut microbiota may link to the mechanistic basis of common metabolic disorders was discussed. We also highlight the independent and synergistic effects of fasting and exercise interventions on metabolic health and provide perspectives for preventing metabolic disorders.

Non-Traditional Risk Factors as Contributors to Cardiovascular Disease

Cardiovascular disease (CVD) remains one of the primary causes of morbidity and mortality worldwide. Classic cardiovascular risk factors, such as hypertension, diabetes mellitus (DM), hyperlipidemia, and smoking, have been well identified and given increased attention in clinical practice. However, the incidence and prevalence of CVD remains high, especially in developing countries. Therefore, there has been more attention to non-traditional CVD risk factors such as gut microbiota, sleep disorders, dietary structure, and psychosocial factors in their important roles in the development of CVD. In this review we summarize the association of non-traditional risk factors with CVD with the aim of further reducing the risk of CVD.

Emerging Roles of Gut Microbial Modulation of Bile Acid Composition in the Etiology of Cardiovascular Diseases

Despite advances in preventive measures and treatment options, cardiovascular disease (CVD) remains the number one cause of death globally. Recent research has challenged the traditional risk factor profile and highlights the potential contribution of non-traditional factors in CVD, such as the gut microbiota and its metabolites. Disturbances in the gut microbiota have been repeatedly associated with CVD, including atherosclerosis and hypertension. Mechanistic studies support a causal role of microbiota-derived metabolites in disease development, such as short-chain fatty acids, trimethylamine-N-oxide, and bile acids, with the latter being elaborately discussed in this review. Bile acids represent a class of cholesterol derivatives that is essential for intestinal absorption of lipids and fat-soluble vitamins, plays an important role in cholesterol turnover and, as more recently discovered, acts as a group of signaling molecules that exerts hormonal functions throughout the body. Studies have shown mediating roles of bile acids in the control of lipid metabolism, immunity, and heart function. Consequently, a picture has emerged of bile acids acting as integrators and modulators of cardiometabolic pathways, highlighting their potential as therapeutic targets in CVD. In this review, we provide an overview of alterations in the gut microbiota and bile acid metabolism found in CVD patients, describe the molecular mechanisms through which bile acids may modulate CVD risk, and discuss potential bile-acid-based treatment strategies in relation to CVD.

The gut microbiota-artery axis: A bridge between dietary lipids and atherosclerosis?

Atherosclerotic cardiovascular disease is one of the major leading global causes of death. Growing evidence has demonstrated that gut microbiota (GM) and its metabolites play a pivotal role in the onset and progression of atherosclerosis (AS), now known as GM-artery axis. There are interactions between dietary lipids and GM, which ultimately affect GM and its metabolites. Given these two aspects, the GM-artery axis may play a mediating role between dietary lipids and AS. Diets rich in saturated fatty acids (SFAs), omega-6 polyunsaturated fatty acids (n-6 PUFAs), industrial trans fatty acids (TFAs), and cholesterol can increase the levels of atherogenic microbes and metabolites, whereas monounsaturated fatty acids (MUFAs), ruminant TFAs, and phytosterols (PS) can increase the levels of antiatherogenic microbes and metabolites. Actually, dietary phosphatidylcholine (PC), sphingomyelin (SM), and omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been demonstrated to affect AS via the GM-artery axis. Therefore, that GM-artery axis acts as a communication bridge between dietary lipids and AS. Herein, we will describe the molecular mechanism of GM-artery axis in AS and discuss the complex interactions between dietary lipids and GM. In particular, we will highlight the evidence and potential mechanisms of dietary lipids affecting AS via GM-artery axis.

Epigenetics and Gut Microbiota Crosstalk: A potential Factor in Pathogenesis of Cardiovascular Disorders

Cardiovascular diseases (CVD) are the leading cause of mortality, morbidity, and "sudden death" globally. Environmental and lifestyle factors play important roles in CVD susceptibility, but the link between environmental factors and genetics is not fully established. Epigenetic influence during CVDs is becoming more evident as its direct involvement has been reported. The discovery of epigenetic mechanisms, such as DNA methylation and histone modification, suggested that external factors could alter gene expression to modulate human health. These external factors also influence our gut microbiota (GM), which participates in multiple metabolic processes in our body. Evidence suggests a high association of GM with CVDs. Although the exact mechanism remains unclear, the influence of GM over the epigenetic mechanisms could be one potential pathway in CVD etiology. Both epigenetics and GM are dynamic processes and vary with age and environment. Changes in the composition of GM have been found to underlie the pathogenesis of metabolic diseases via modulating epigenetic changes in the form of DNA methylation, histone modifications, and regulation of non-coding RNAs. Several metabolites produced by the GM, including short-chain fatty acids, folates, biotin, and trimethylamine-N-oxide, have the potential to regulate epigenetics, apart from playing a vital role in normal physiological processes. The role of GM and epigenetics in CVDs are promising areas of research, and important insights in the field of early diagnosis and therapeutic approaches might appear soon.

Research Landscape on Atherosclerotic Cardiovascular Disease and Inflammation: A Bibliometric and Visualized Study

Background

The atherosclerotic cardiovascular disease (ASCVD) is a major killer and health care burden worldwide. Atherosclerosis, the common pathological foundation, has been associated with inflammation over the past few years. Some promising results also have emerged suggesting the role of targeting inflammation as a potential therapeutic option to reduce cardiovascular events. In light of the pathogenic role that inflammation plays in ASCVD, we propose to evaluate the worldwide research architecture for ASCVD and inflammation using bibliometric analysis.

Methods

A search of the Web of Science Core Collection of Clarivate Analytics was performed for articles in the field published between 2012 and 2022. The number of publications per year has been visualized using GraphPad Prism through time. CiteSpace and VOSviewer were used to generate knowledge maps about the collaboration of countries, institutions, and authors, and to represent the landscape on ASCVD and inflammation research as well as to reveal current foci.

Results

There were a total of 19,053 publications examined in this study. The most publications came from China (6232, 32.71%). Capital Med Univ was the most productive institution (410, 2.15%). Christian Weber published the greatest number of articles (75, 0.39%). PloS one was identified as the most prolific journal (706, 3.71%). Circulation was the most co-cited journal (13276, 2.81%). Keywords with the ongoing strong citation bursts were "nucleotide-binding oligomerization (NOD), Leucine-rich repeat (LRR)-containing protein (NLRP3) inflammasome", "intestinal microbiota", "exosome", "lncRNAs", etc.

Conclusions

It can be shown that ASCVD and inflammation research benefited from manuscripts that had a high impact on the scientific community. Asian, European and North American countries dominated in the field in terms of quantitative, qualitative and collaborative parameters. The NLRP3 inflammasome, gut microbiota and trimethylamine N-oxide, autophagy, lncRNAs, exosomes, and nuclear factor erythroid 2-related factor 2 were described to be hot themes in the field.

Polyphenols–Gut–Heart: An Impactful Relationship to Improve Cardiovascular Diseases

A healthy gut provides the perfect habitat for trillions of bacteria, called the intestinal microbiota, which is greatly responsive to the long-term diet; it exists in a symbiotic relationship with the host and provides circulating metabolites, hormones, and cytokines necessary for human metabolism. The gut–heart axis is a novel emerging concept based on the accumulating evidence that a perturbed gut microbiota, called dysbiosis, plays a role as a risk factor in the pathogenesis of cardiovascular disease. Consequently, recovery of the gut microbiota composition and function could represent a potential new avenue for improving patient outcomes. Despite their low absorption, preclinical evidence indicates that polyphenols and their metabolites are transformed by intestinal bacteria and halt detrimental microbes’ colonization in the host. Moreover, their metabolites are potentially effective in human health due to antioxidant, anti-inflammatory, and anti-cancer effects. The aim of this review is to provide an overview of the causal role of gut dysbiosis in the pathogenesis of atherosclerosis, hypertension, and heart failure; to discuss the beneficial effects of polyphenols on the intestinal microbiota, and to hypothesize polyphenols or their derivatives as an opportunity to prevent and treat cardiovascular diseases by shaping gut eubiosis.

Laboratory Grown Biofilms of Bacteria Associated with Human Atherosclerotic Carotid Arteries Release Collagenases and Gelatinases during Iron-Induced Dispersion

The association of bacteria with arterial plaque lesions in patients with atherosclerosis has been widely reported. However, the role these bacteria play in the progression of atherosclerosis is still unclear. Previous work in our lab has demonstrated that bacteria exist in carotid artery plaques as biofilm deposits. Biofilms are communities of microorganisms enmeshed within a protective, self-produced extracellular matrix and have been shown to contribute to chronic infections in humans. Biofilm communities have the potential to impact surrounding tissues in an infection if they undergo a dispersion response, releasing bacteria into the surrounding environment by enzymatic degradation of the extracellular matrix. One concern relating to these enzymes is that they could cause collateral damage to host tissues. In this study, we present an in vitro multispecies biofilm culturing model used to investigate the potential role of bacterial biofilm dispersion in the progression of atherosclerosis. This work has demonstrated an increase in cell release from mixed-species biofilms formed by bacteria associated with human carotid arterial plaque deposits following treatment with iron or a combination of norepinephrine and transferrin. Greater extracellular lipase, protease, and collagenase/gelatinase activity was also associated with iron-treated biofilms. The results of this work suggest that bacteria in this model undergo iron-induced biofilm dispersion, as evidenced by the increased cell release and higher enzyme activity following treatment. This work demonstrates the potential for multispecies biofilm dispersion to contribute to arterial tissue degradation by bacteria and suggests that in atherosclerotic infections, biofilm dispersion may contribute to thrombogenesis, which can lead to heart attack or stroke. IMPORTANCE Atherosclerosis, or hardening of the arteries, is a leading cause of congestive heart failure, heart attack, and stroke in humans. Mounting evidence, in the literature and from our lab, points to the regular involvement of bacteria within arterial plaque deposits in patients with advanced atherosclerosis. Very little is known about the behavior of these bacteria and whether they may contribute to tissue damage in infected arteries. Tissue damage within the arterial plaque lesion can lead to rupture of the plaque contents into the bloodstream, where a clot may form, resulting in a potential heart attack or stroke. This study shows that plaque-associated bacteria, when cultured as mixed-species biofilms in the laboratory, can release degradative enzymes into their environment as the result of a dispersion response triggered by iron. These degradative enzymes can digest proteins and lipids which are associated with the tissues that separate the plaque lesion from the arterial lumen. Thus, this study demonstrates that if mixed species biofilms are induced to undergo dispersion in an infected atherosclerotic lesion when exposed to an elevated concentration of free iron, they have the potential to contribute to the weakening of arterial tissues, which may contribute to atherosclerotic plaque destabilization.

Genome-wide identification of genetic requirements of Pseudomonas aeruginosa PAO1 for rat cardiomyocyte (H9C2) infection by insertion sequencing

Pseudomonas aeruginosa is a major infectious agent among Gram-negative bacteria, which causes both acute and chronic infections. Infections due to P. aeruginosa are hard to treat, as it entails various strategies like virulence factors synthesis, drug efflux systems & resistance and protein secretion systems during pathogenesis. Despite extensive research in Pseudomonas pathogenesis, novel drug targets and potential therapeutic strategies are urgently needed. In this study, we investigated the genetic requirements of P. aeruginosa PAO1 for rat cardiomyocyte (H9C2) infection by insertion sequencing (INSeq). A mutant library comprising ~70,000 mutants of PAO1 was generated and the differentiated form of H9C2 cells (d-H9C2) was infected with the library. The infected d-H9C2 cells were maintained with antibiotic-protection and without any antibiotics in the growth media for 24 h. Subsequently, DNA library for INSeq was prepared, sequenced and fitness analysis was performed. One hundred and thirteen mutants were negatively selected in the infection condition with antibiotic-protection, whereas 143 mutants were negatively selected in antibiotic-free condition. Surprisingly, a higher number of mutants showed enriched fitness than the mutants of reduced fitness during the infection. We demonstrated that the genes associated with flagella and T3SS are important for adhesion and invasion of cardiomyocytes, while pili and proteases are conditionally essential during host cell lysis. Hence, our findings highlight the essential genes for cardiomyocyte infection, particularly during the intracellular phase. The aerotaxis receptor Aer, plays a critical role during intracellular life. Genes such as flgE, flgF, flhA, flhB, fliA, fliC, fliF, motA, aotJ, aer, wbpJ, ponA, fleQ, PA5205, hmgA, trkH and pslH are essential for infection.

Interaction between bacteria and cholesterol crystals: Implications for endocarditis and atherosclerosis

Background

The interaction between pathogenic bacteria and cholesterol crystals (CCs) has not been investigated. However, CCs are found extensively in atherosclerotic plaques and sclerotic cardiac valves. Interactions between pathogenic bacteria and CCs could provide insights into destabilization of atherosclerotic plaques and bacterial adhesion to cardiac valves.

Methods

Staphylococcus aureus and Pseudomonas aeruginosa were used to assess in vitro bacterial adhesion to CCs and proliferation in the presence of CCs compared to plastic microspheres and glass shards as controls. Ex vivo studies evaluated bacterial adhesion to atherosclerotic rabbit arteries compared to normal arteries and human atherosclerotic carotid plaques compared to normal carotid arteries. Scanning electron microscopy (SEM) was used to visualize bacterial adhesion to CCs and confocal microscopy was used to detect cholesterol binding to bacteria grown in the presence or absence of CCs.

Results

In vitro, S. aureus and P. aeruginosa displayed significantly greater adhesion, 36% (p<0.0001) and 89% (p<0.0001), respectively, and growth upon exposure to CCs compared to microspheres or glass shards. Rabbit and human atherosclerotic arteries contained significantly greater bacterial burdens compared to controls (4× (p<0.0004); 3× (p<0.019), respectively. SEM demonstrated that bacteria adhered and appeared to degrade CCs. Consistent with this, confocal microscopy indicated increased cholesterol bound to the bacterial cells.

Conclusions

This study is the first to demonstrate an interaction between bacteria and CCs showing that bacteria dissolve and bind to CCs. This interaction helps to elucidate adhesion of bacteria to sclerotic valves and atherosclerotic plaques that may contribute to endocarditis and plaque destabilization.

Microbiome and metabolome features of the cardiometabolic disease spectrum

Previous microbiome and metabolome analyses exploring non-communicable diseases have paid scant attention to major confounders of study outcomes, such as common, pre-morbid and co-morbid conditions, or polypharmacy. Here, in the context of ischemic heart disease (IHD), we used a study design that recapitulates disease initiation, escalation and response to treatment over time, mirroring a longitudinal study that would otherwise be difficult to perform given the protracted nature of IHD pathogenesis. We recruited 1,241 middle-aged Europeans, including healthy individuals, individuals with dysmetabolic morbidities (obesity and type 2 diabetes) but lacking overt IHD diagnosis and individuals with IHD at three distinct clinical stages—acute coronary syndrome, chronic IHD and IHD with heart failure—and characterized their phenome, gut metagenome and serum and urine metabolome. We found that about 75% of microbiome and metabolome features that distinguish individuals with IHD from healthy individuals after adjustment for effects of medication and lifestyle are present in individuals exhibiting dysmetabolism, suggesting that major alterations of the gut microbiome and metabolome might begin long before clinical onset of IHD. We further categorized microbiome and metabolome signatures related to prodromal dysmetabolism, specific to IHD in general or to each of its three subtypes or related to escalation or de-escalation of IHD. Discriminant analysis based on specific IHD microbiome and metabolome features could better differentiate individuals with IHD from healthy individuals or metabolically matched individuals as compared to the conventional risk markers, pointing to a pathophysiological relevance of these features.

By studying individuals along a spectrum of cardiometabolic disease and adjusting for effects of lifestyle and medication, this investigation identifies alterations of the metabolome and microbiome from dysmetabolic conditions, such as obesity and type 2 diabetes, to ischemic heart disease.

Diet, Lifestyle, Smoking

Cardiovascular disease is the leading cause of death globally The past few decades have shown that especially low- and middle-income countries have undergone rapid industrialization, urbanization, economic development and market globalization. Although these developments led to many positive changes in health outcomes and increased life expectancies, they all also caused inappropriate dietary patterns, physical inactivity and obesity. Evidence shows that a large proportion of the cardiovascular disease burden can be explained by behavioural factors such as low physical activity, unhealthy diet and smoking. Controlling these risk factors from early ages is important for maintaining cardiovascular health. Even in patients with genetic susceptibility to cardiovascular disease, risk factor modification is beneficial.Despite the tremendous advances in the medical treatment of cardiovascular risk factors to reduce overall cardiovascular risk, the modern lifestyle which has led to greater sedentary time, lower participation in active transport and time spent in leisure or purposeful physical activity, unhealthy diets and increased exposure to stress, noise and pollution have diminished the beneficial effects of contemporary medical cardiovascular prevention strategies. Therefore attenuating or eliminating these health risk behaviours and risk factors is imperative in the prevention of cardiovascular diseases.

The Relationship among Physical Activity, Intestinal Flora, and Cardiovascular Disease

Cardiovascular diseases (CVDs), which are associated with high morbidity and mortality worldwide, include atherosclerosis (AS), hypertension, heart failure (HF), atrial fibrillation, and myocardial fibrosis. CVDs are influenced by the diversity, distribution, and metabolites of intestinal microflora, and their risk can be reduced through physical activity (PA) such as regular exercise. PA benefits the metabolic changes that occur in the gut microbiota (GM). The major metabolites of the GM influence pathogenesis of CVDs through various pathways. However, the relationship between PA and GM is less well understood. In this review, we discuss the impacts of different types of PA on intestinal microflora including the diversity, distribution, metabolites, and intestinal barrier function including intestinal permeability, with a focus on the mechanisms by which PA affects GM. We also discuss how GM influences CVDs. Finally, we summarize current research and knowledge on the effects of PA on CVD via regulation of the GM and intestinal function. More understanding of relevant relationship between PA and GM may provide hope for the prevention or treatment of CVDs. Furthermore, a better understanding of regulation of the GM and intestinal function may lead to novel diagnostic and therapeutic strategies, improving the clinical care of CVD patients.

Can manipulation of gut microbiota really be transformed into an intervention strategy for cardiovascular disease management?

Recent advancement in manipulation techniques of gut microbiota either ex vivo or in situ has broadened its plausible applicability for treating various diseases including cardiovascular disease. Several reports suggested that altering gut microbiota composition is an effective way to deal with issues associated with managing cardiovascular diseases. However, actual translation of gut microbiota manipulation-based techniques into cardiovascular-therapeutic approach is still questionable. This review summarized the evidence on challenges, opportunities, recent development, and future prospects of gut microbiota manipulation for targeting cardiovascular diseases. Initially, issues associated with current cardiovascular diseases treatment strategy, association of gut microbiota with cardiovascular disease, and its influence on cardiovascular drugs were discussed, followed by applicability of gut microbiota manipulation as a cardiovascular disease intervention strategy along with its challenges and future prospects. Despite the fact that the gut microbiota is rugged, interventions like probiotics, prebiotics, synbiotics, fecal microbiota transplantation, fecal virome transplantation, antibiotics, diet changes, and exercises could manipulate it. Advanced techniques like administration of engineered bacteriophages and bacteria could also be employed. Intensive exploration revealed that if sufficiently controlled approach and proper monitoring were applied, gut microbiota could provide a compelling answer for cardiovascular therapy.

Inter-Kingdom Signaling of Stress Hormones: Sensing, Transport and Modulation of Bacterial Physiology

Prokaryotes and eukaryotes have coexisted for millions of years. The hormonal communication between microorganisms and their hosts, dubbed inter-kingdom signaling, is a recent field of research. Eukaryotic signals such as hormones, neurotransmitters or immune system molecules have been shown to modulate bacterial physiology. Among them, catecholamines hormones epinephrine/norepinephrine, released during stress and physical effort, or used therapeutically as inotropes have been described to affect bacterial behaviors (i.e., motility, biofilm formation, virulence) of various Gram-negative bacteria (e.g., Escherichia coli, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Vibrio sp.). More recently, these molecules were also shown to influence the physiology of some Gram-positive bacteria like Enterococcus faecalis. In E. coli and S. enterica, the stress-associated mammalian hormones epinephrine and norepinephrine trigger a signaling cascade by interacting with the QseC histidine sensor kinase protein. No catecholamine sensors have been well described yet in other bacteria. This review aims to provide an up to date report on catecholamine sensors in eukaryotes and prokaryotes, their transport, and known effects on bacteria.

Association between Oral Pathology, Carotid Stenosis, and Oral Bacterial DNA in Cerebral Thrombi of Patients with Stroke

Methods

Thrombus aspirates and control arterial blood were taken from 71 patients (70.4% male; mean age, 67.4 years) with acute ischemic stroke. Tooth pathology was registered using CT scans. Carotid stenosis was estimated with CTA and ultrasonography. The presence of bacterial DNA from aspirated thrombi was determined using quantitative PCR. We also analyzed the presence of these bacterial DNAs in carotid endarterectomies from patients with peripheral arterial disease.

Results

Bacterial DNA was found in 59 (83.1%) of the thrombus aspirates (median, 8.6-fold). Oral streptococcal DNA was found in 56 (78.9%) of the thrombus aspirates (median, 5.1-fold). DNA from A. actinomycetemcomitans and P. gingivalis was not found. Most patients suffered from poor oral health and had in median 19.0 teeth left. Paradoxically, patients with better oral health had more oral streptococcal DNA in their thrombus than the group with the worst pathology (p = 0.028). There was a trend (OR 7.122; p = 0.083) in the association of ≥50% carotid artery stenosis with more severe dental pathology. Oral streptococcal DNA was detected in 2/6 of carotid endarterectomies.

Conclusions

Stroke patients had poor oral health which tended to associate with their carotid artery stenosis. Although oral streptococcal DNA was found in thrombus aspirates and carotid endarterectomy samples, the amount of oral streptococcal DNA in thrombus aspirates was the lowest among those with the most severe oral pathology. These results suggest that the association between poor oral health and acute ischemic stroke is linked to carotid artery atherosclerosis.

Exercise Effects On Cardiovascular Disease: From Basic Aspects To Clinical Evidence

Cardiovascular (CV) disease (CVD) remains the leading cause of major morbidity and CVD- and all-cause mortality in most of the world. It is now clear that regular physical activity (PA) and exercise training (ET) induces a wide range of direct and indirect physiologic adaptations and pleiotropic benefits for human general and CV health. Generally, higher levels of PA, ET, and cardiorespiratory fitness (CRF) are correlated with reduced risk of CVD, including myocardial infarction, CVD-related death, and all-cause mortality. Although exact details regarding the ideal doses of ET, including resistance and, especially, aerobic ET, as well as the potential adverse effects of extreme levels of ET, continue to be investigated, there is no question that most of the world's population have insufficient levels of PA/ET, and many also have lower than ideal levels of CRF. Therefore, assessment and promotion of PA, ET, and efforts to improve levels of CRF should be integrated into all health professionals' practices worldwide. In this state-of-the-art review, we discuss the exercise effects on many areas related to CVD, from basic aspects to clinical practice.

Lipopolysaccharide from the commensal microbiota of the breast enhances cancer growth: role of S100A7 and TLR4

The role of commensal bacterial microbiota in the pathogenesis of human malignancies has been a research field of incomparable progress in recent years. Although breast tissue is commonly assumed to be sterile, recent studies suggest that human breast tissue may contain a bacterial microbiota. In this study, we used an immune‐competent orthotopic breast cancer mouse model to explore the existence of a unique and independent bacterial microbiota in breast tumors. We observed some similarities in breast cancer microbiota with skin; however, breast tumor microbiota was mainly enriched with Gram‐negative bacteria, serving as a primary source of lipopolysaccharide (LPS). In addition, dextran sulfate sodium (DSS) treatment in late‐stage tumor lesions increased LPS levels in the breast tissue environment. We also discovered an increased expression of S100A7 and low level of TLR4 in late‐stage tumors with or without DSS as compared to early‐stage tumor lesions. The treatment of breast cancer cells with LPS increased the expression of S100A7 in breast cancer cells in vitro. Furthermore, S100A7 overexpression downregulated TLR4 and upregulated RAGE expression in breast cancer cells. Analysis of human breast cancer samples also highlighted the inverse correlation between S100A7 and TLR4 expression. Overall, these findings suggest that the commensal microbiota of breast tissue may enhance breast tumor burden through a novel LPS/S100A7/TLR4/RAGE signaling axis.

Effect of adrenaline and noradrenaline on biofilm formation and virulence factors of Streptococcus mutans UA159

OBJECTIVES

To evaluate in vitro the effects of adrenaline and noradrenaline on the biofilm formation on orthodontic brackets, acid production and expression of virulence genes of Streptococcus mutans UA159 (S. mutans).

DESIGN

S. mutans UA159 biofilm was formed on orthodontic brackets under exposure to adrenaline (100 μM), noradrenaline (50 μM) or PBS solution (control group) in triptone-yeast extract with 1 % sucrose. After 24 h, biofilm formation was quantified through Colony Forming Units / mL (CFU/mL) and RNA was extracted to perform gene expression analysis through real-time reverse transcriptase-PCR (RT-qPCR). Evaluation of acid production was carried out on planktonic cultures for 6 h. One-way ANOVA followed by Tukey's test was carried to determine statistical difference. The level of significance was set at 5 %.

RESULTS

Catecholamines stimulated biofilm formation of S. mutans in orthodontic brackets (p < 0,05) but did not interfere with acid production (pH reduction) or the expression of the tested genes related to biofilm formation (gtfB, gtfC, gbpA, gbpB, gbpC, gbpD and brpA), aciduric (relA) and acidogenic properties (ldh).

CONCLUSIONS

The present study was the first to demonstrate that catecholamines can stimulate S. mutans UA159 biofilm formation. These findings can contribute to clarify the role of stress on bacterial metabolism and contribute to the understanding of a possible role on caries development, mainly in orthodontic patients.

Metagenomics Analysis of Thrombus Samples Retrieved from Mechanical Thrombectomy

Purpose

The purpose of this study was to assess the microbiota in middle cerebral artery thrombi retrieved in mechanical thrombectomy arising out of symptomatic carotid plaque within 6 hours of acute ischemic stroke. Thrombi were subjected to next-generation sequencing for a bacterial signature to determine their role in atherosclerosis.

Materials and Methods

We included 4 human middle cerebral artery thrombus samples (all patients were male). The median age for the patients was 51±13.6 years. Patients enrolled in the study from Pacific Medical University and Hospital underwent mechanical thrombectomy in the stroke window period. All patients underwent brain magnetic resonance angiography (MRA) and circle of Willis and neck vessel MRA along with the standard stroke workup to establish stroke etiology. Only patients with symptomatic carotid stenosis and tandem lesions with ipsilateral middle cerebral artery occlusion were included in the study. Thrombus samples were collected, stored at –80 degrees, and subjected to metagenomics analysis.

Results

Of the 4 patients undergoing thrombectomy for diagnosis with ischemic stroke, all thrombi recovered for bacterial DNA in qPCR were positive. More than 27 bacteria were present in the 4 thrombus samples. The majority of bacteria were Lactobacillus, Stenotrophomonas, Pseudomonas, Staphylococcus, and Finegoldia.

Conclusion

Genesis of symptomatic atherosclerotic carotid plaque leading to thromboembolism could be either due to direct mechanisms like acidification and local inflammation of plaque milieu with lactobacillus, biofilm dispersion leading to inflammation like with pseudomonas fluorescence, or enterococci or indirect mechanisms like Toll 2 like signaling by gut microbiota.

Antimicrobial Synergy of Silver-Platinum Nanohybrids With Antibiotics

Various bacterial pathogens are responsible for nosocomial infections resulting in critical pathophysiological conditions, mortality, and morbidity. Most of the bacterial infections are associated with biofilm formation, which is resistant to the available antimicrobial drugs. As a result, novel bactericidal agents need to be fabricated, which can effectively combat the biofilm-associated bacterial infections. Herein, for the first time we report the antimicrobial and antibiofilm properties of silver-platinum nanohybrids (AgPtNHs), silver nanoparticles (AgNPs), and platinum nanoparticles (PtNPs) against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The AgPtNHs were synthesized by a green route using Dioscorea bulbifera tuber extract at 100°C for 5 h. The AgPtNHs ranged in size from 20 to 80 nm, with an average of ∼59 nm. AgNPs, PtNPs, and AgPtNHs showed a zeta potential of -14.46, -1.09, and -11.39 mV, respectively. High antimicrobial activity was observed against P. aeruginosa and S. aureus and AgPtNHs exhibited potent antimicrobial synergy in combination with antibiotics such as streptomycin, rifampicin, chloramphenicol, novobiocin, and ampicillin up to variable degrees. Interestingly, AgPtNHs could inhibit bacterial biofilm formation significantly. Hence, co-administration of AgPtNHs and antibiotics may serve as a powerful strategy to treat bacterial infections.

Biofilm dispersion

The formation of microbial biofilms enables single planktonic cells to assume a multicellular mode of growth. During dispersion, the final step of the biofilm life cycle, single cells egress from the biofilm to resume a planktonic lifestyle. As the planktonic state is considered to be more vulnerable to antimicrobial agents and immune responses, dispersion is being considered a promising avenue for biofilm control. In this Review, we discuss conditions that lead to dispersion and the mechanisms by which native and environmental cues contribute to dispersion. We also explore recent findings on the role of matrix degradation in the dispersion process, and the distinct phenotype of dispersed cells. Last, we discuss the translational and therapeutic potential of dispersing bacteria during infection.

Porphyromonas gingivalis disrupts vascular endothelial homeostasis in a TLR-NF-κB axis dependent manner

Cardiovascular disease is still the leading cause of mortality worldwide. Vascular endothelial dysfunction is viewed as the initial step of most cardiovascular diseases. Many studies have indicated that periodontal pathogens, especially Porphyromonas gingivalis, are closely correlated with vascular endothelial homeostasis, but the function of P. gingivalis and the underlying mechanisms are still elusive. To illuminate the effects and elucidate the mechanisms of P. gingivalis on endothelial structural integrity, we developed P. gingivalis infection models in vivo and in vitro. Endothelial cell proliferation, differentiation and apoptosis were detected. Here, we showed that P. gingivalis can impair endothelial integrity by inhibiting cell proliferation and inducing endothelial mesenchymal transformation and apoptosis of endothelial cells, which reduce the cell levels and cause the endothelium to lose its ability to repair itself. A mechanistic analysis showed that TLR antagonist or NF-κB signalling inhibitor can largely rescue the damaged integrity of the endothelium caused by P. gingivalis, suggesting that TLR-NF-κB signalling plays a vital role in vascular endothelial homeostasis destroyed by P. gingivalis. These results suggest a potential intervention method for the prevention and treatment of cardiovascular disease.

Gut Microbiota in Hypertension and Atherosclerosis: A Review

Gut microbiota and its metabolites such as short chain fatty acids (SCFA), lipopolysaccharides (LPS), and trimethylamine-N-oxide (TMAO) impact cardiovascular health. In this review, we discuss how gut microbiota and gut metabolites can affect hypertension and atherosclerosis. Hypertensive patients were shown to have lower alpha diversity, lower abundance of SCFA-producing microbiota, and higher abundance of gram-negative bacteria, which are a source of LPS. Animal studies point towards a direct role for SCFAs in blood pressure regulation and show that LPS has pro-inflammatory effects. Translocation of LPS into the systemic circulation is a consequence of increased gut permeability. Atherosclerosis, a multifactorial disease, is influenced by the gut microbiota through multiple pathways. Many studies have focused on the pro-atherogenic role of TMAO, however, it is not clear if this is a causal factor. In addition, gut microbiota play a key role in bile acid metabolism and some interventions targeting bile acid receptors tend to decrease atherosclerosis. Concluding, gut microbiota affect hypertension and atherosclerosis through many pathways, providing a wide range of potential therapeutic targets. Challenges ahead include translation of findings and mechanisms to humans and development of therapeutic interventions that target cardiovascular risk by modulation of gut microbes and metabolites.

Oral Bacterial Signatures in Cerebral Thrombi of Patients With Acute Ischemic Stroke Treated With Thrombectomy

Background

Chronic infections have been reported to be risk factors for both coronary heart disease and ischemic stroke. DNA of oral bacteria, mainly from the viridans streptococci group, has been detected in coronary thrombus aspirates of myocardial infarction and cerebral aneurysms. Viridans streptococci are known to cause infective endocarditis and possess thrombogenic properties. We studied the presence of oral bacterial DNA in thrombus aspirates of patients with acute ischemic stroke treated with mechanical thrombectomy.

Methods and Results

Thrombus aspirates and arterial blood were taken from 75 patients (69% men; mean age, 67 years) with acute ischemic stroke. The presence of Streptococcus species, mainly the Streptococcus mitis group, belonging to viridans streptococci as well as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in samples were determined using a quantitative polymerase chain reaction with specific primers and probes. The relative amount of bacterial DNA in a sample was determined with the comparative threshold cycle method. Bacterial DNA was detected in 84% (n=63) of aspired thrombi, and 16% (n=12) of samples were considered bacterial DNA negative. DNA of Streptococcus species, mainly the S mitis group, was found in 79% (n=59) of samples. The median relative amount of Streptococcus species DNA was 5.10‐fold higher compared with the control blood samples from the same patients. All thrombi were negative for both P gingivalis and A actinomycetemcomitans.

Conclusions

This is the first study showing the common presence of bacterial DNA from viridans streptococci in aspired thrombi of patients with acute ischemic stroke. Streptococcal bacteria, mostly of oral origin, may contribute to the progression and thrombotic events of cerebrovascular diseases.

Phenotype and Response to PAMPs of Human Monocyte-Derived Foam Cells Obtained by Long-Term Culture in the Presence of oxLDLs

Cholesterol-laden, foam macrophages constitute the most characteristic component of human atherosclerotic plaques. Persistent uptake of oxLDLs results in accumulation of lipid bodies inside the cells and determines their phenotype and subsequent functions. In this work, we describe the phenotype of human monocyte-derived foam cells obtained by differentiation in the constant presence of oxLDLs for 30 days (prolonged-hMDFCs). Although neither the total cellular nor the cell surface expression of Toll-like receptors (TLR) was regulated by oxLDLs, the prolonged-hMDFCs changed dramatically their responsiveness to TLR ligands and inactivated bacteria. Using multiplex technology, we observed an acute decline in cytokine and chemokine production after surface and endosomal TLR stimulation with the exception of TLR2/6 triggering with agonists Pam2CSK4 and MALP-2. We also noted significant reduction of some surface receptors which can have accessory function in recognition of particulate antigens (CD47, CD81, and CD11b). In contrast, the prolonged-hMDFCs responded to inflammasome activation by LPS/nigericin with extensive, necrotic type cell death, which was partially independent of caspase-1. This pyroptosis-like cell death was aggravated by necrostatin-1 and rapamycin. These findings identify a potential contribution of mature foam cells to inflammatory status by increasing the immunogenic cell death burden. The observed cross-talk between foam cell death pathways may lead to recognition of a potential new marker for atherosclerosis disease severity. Overall, our study demonstrates that, in contrast to other cellular models of foam cells, the prolonged-hMDFCs acquire a functional phenotype which may help understanding the role of foam cells in the pathogenesis of atherosclerosis.

Mechanisms underlying the association between periodontitis and atherosclerotic disease

Atherosclerosis is central to the pathology of cardiovascular diseases, a group of diseases in which arteries become occluded with atheromas that may rupture, leading to different cardiovascular events, such as myocardial infarction or ischemic stroke. There is a large body of epidemiologic and animal model evidence associating periodontitis with atherosclerotic disease, and many potential mechanisms linking these diseases have been elucidated. This chapter will update knowledge on these mechanisms, which generally fall into 2 categories: microbial invasion and infection of atheromas; and inflammatory and immunologic. With respect to the invasion and infection of atheromas, it is well established that organisms from the subgingival biofilm can enter the circulation and lodge in most distant tissues. Bacteremias resulting from oral interventions, and even oral hygiene activities, are well documented. More recently, indirect routes of entry of oral organisms (via phagocytes or dendritic cells) have been described for many oral organisms, into many tissues. Such organisms include the periodontal pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Tannerella forsythia, and Fusobacterium nucleatum. Intracellular survival of these organisms with dissemination to distant sites (The Trojan Horse approach) has been described. Their relative contribution to atheroma formation and progression has been studied mainly in experimental research, with results demonstrating that these organisms can invade endothelial cells and phagocytic cells within the atheroma, leading to pathogenic changes and progression of the atheroma lesion. The second category of mechanisms potentially linking periodontitis to atherosclerosis includes the dumping of inflammatory mediators originating from periodontal lesions into the systemic circulation. These inflammatory mediators, such as C-reactive protein, matrix metalloproteinases, fibrinogen, and other hemostatic factors, would further accelerate atheroma formation and progression, mainly through oxidative stress and inflammatory dysfunction. Moreover, direct effects on lipid oxidation have also been described. In summary, the evidence supports the concept that periodontitis enhances the levels of systemic mediators of inflammation that are risk factors for atherosclerotic diseases.

Potential genes and pathways along with immune cells infiltration in the progression of atherosclerosis identified via microarray gene expression dataset re-analysis

OBJECTIVE

Atherosclerosis is a chronic inflammatory process characterized by the accumulation and formation of lipid-rich plaques within the layers of the arterial wall. Although numerous studies have reported the underlying pathogenesis, no data-based studies have been conducted to analyze the potential genes and immune cells infiltration in the different stages of atherosclerosis via bioinformatics analysis.

METHODS

In this study, we downloaded GSE100927 and GSE28829 from NCBI-GEO database. Gene ontology and pathway enrichment were performed via the DAVID database. The protein interaction network was constructed via STRING. Enriched hub genes were analyzed by the Cytoscape software. The evaluation of the infiltrating immune cells in the dataset samples was performed by the CIBERSORT algorithm.

RESULTS

We identified 114 common upregulated differentially expressed genes and 22 common downregulated differentially expressed genes. (adjust p value < 0.01 and log FC ≥ 1). A cluster of 10 genes including CYBA, SLC11A1, FCER1G, ITGAM, ITGB2, CD53, ITGAX, VAMP8, CLEC5A, and CD300A were found to be significant. Through the deconvolution algorithm CIBERSORT, we analyzed the significant alteration of immune cells infiltration in the progression of atherosclerosis with the threshold of the Wilcoxon test at p value <0.05.

CONCLUSIONS

These results may reveal the underlying correlations between genes and immune cells in atherosclerosis, which enable us to investigate the novel insights for the development of treatments and drugs.

Bacterial Biofilm and its Role in the Pathogenesis of Disease

Recognition of the fact that bacterial biofilm may play a role in the pathogenesis of disease has led to an increased focus on identifying diseases that may be biofilm-related. Biofilm infections are typically chronic in nature, as biofilm-residing bacteria can be resilient to both the immune system, antibiotics, and other treatments. This is a comprehensive review describing biofilm diseases in the auditory, the cardiovascular, the digestive, the integumentary, the reproductive, the respiratory, and the urinary system. In most cases reviewed, the biofilms were identified through various imaging technics, in addition to other study approaches. The current knowledge on how biofilm may contribute to the pathogenesis of disease indicates a number of different mechanisms. This spans from biofilm being a mere reservoir of pathogenic bacteria, to playing a more active role, e.g., by contributing to inflammation. Observations also indicate that biofilm does not exclusively occur extracellularly, but may also be formed inside living cells. Furthermore, the presence of biofilm may contribute to development of cancer. In conclusion, this review shows that biofilm is part of many, probably most chronic infections. This is important knowledge for development of effective treatment strategies for such infections.

Association of suboptimal health status with intestinal microbiota in Chinese youths

Suboptimal health status (SHS), a physical state between health and disease, is a subclinical and reversible stage of chronic disease. Previous studies have shown alterations in the intestinal microbiota in patients with some chronic diseases. This study aimed to investigate the association between SHS and intestinal microbiota in a case-control study with 50 SHS individuals and 50 matched healthy controls. Intestinal microbiota was analysed by MiSeq 250PE. Alpha diversity of intestinal microbiota in SHS individuals was higher compared with that of healthy controls (Simpson index, W = 2238, P = .048). Beta diversity was different between SHS and healthy controls (P = .018). At the phylum level, the relative abundance of Verrucomicrobia was higher in the SHS group than that in the controls (W = 2201, P = .049). Compared with that of the control group, nine genera were significantly higher and five genera were lower in abundance in the SHS group (all P < .05). The intestinal microbiota, analysed by a random forest model, was able to distinguish individuals with SHS from the controls, with an area under the curve of 0.79 (95% confidence interval: 0.77-0.81). We demonstrated that the alteration of intestinal microbiota occurs with SHS, an early stage of disease, which might shed light on the importance of intestinal microbiota in the primary prevention of noncommunicable chronic diseases.

Exercise benefits in cardiovascular disease: beyond attenuation of traditional risk factors

Despite strong scientific evidence supporting the benefits of regular exercise for the prevention and management of cardiovascular disease (CVD), physical inactivity is highly prevalent worldwide. In addition to merely changing well-known risk factors for systemic CVD, regular exercise can also improve cardiovascular health through non-traditional mechanisms. Understanding the pathways through which exercise influences different physiological systems is important and might yield new therapeutic strategies to target pathophysiological mechanisms in CVD. This Review includes a critical discussion of how regular exercise can have antiatherogenic effects in the vasculature, improve autonomic balance (thereby reducing the risk of malignant arrhythmias), and induce cardioprotection against ischaemia-reperfusion injury, independent of effects on traditional CVD risk factors. This Review also describes how exercise promotes a healthy anti-inflammatory milieu (largely through the release of muscle-derived myokines), stimulates myocardial regeneration, and ameliorates age-related loss of muscle mass and strength, a frequently overlooked non-traditional CVD risk factor. Finally, we discuss how the benefits of exercise might also occur via promotion of a healthy gut microbiota. We argue, therefore, that a holistic view of all body systems is necessary and useful when analysing the role of exercise in cardiovascular health.

Human antibody repertoire frequently includes antibodies to a bacterial biofilm associated protein

We have previously described a native human monoclonal antibody, TRL1068, that disrupts bacterial biofilms by extracting from the biofilm matrix key scaffolding proteins in the DNABII family, which are present in both gram positive and gram negative bacterial species. The antibiotic resistant sessile bacteria released from the biofilm then revert to the antibiotic sensitive planktonic state. Qualitative resensitization to antibiotics has been demonstrated in three rodent models of acute infections. We report here the surprising discovery that antibodies against the target family were found in all twenty healthy humans surveyed, albeit at a low level requiring a sensitive single B-cell assay for detection. We have cloned 21 such antibodies. Aside from TRL1068, only one (TRL1330) has all the biochemical properties believed necessary for pharmacological efficacy (broad spectrum epitope specificity and high affinity). We suggest that the other anti-DNABII antibodies, while not necessarily curative, reflect an immune response at some point in the donor's history to these components of biofilms. Such an immune response could reflect exposure to bacterial reservoirs that have been previously described in chronic non-healing wounds, periodontal disease, chronic obstructive pulmonary disease, colorectal cancer, rheumatoid arthritis, and atherosclerotic artery explants. The detection of anti-DNABII antibodies in all twenty surveyed donors with no active infection suggests that bacterial biofilm reservoirs may be present periodically in most healthy individuals. Biofilms routinely shed bacteria, creating a continuous low level inflammatory stimulus. Since chronic subclinical inflammation is thought to contribute to most aging-related diseases, suppression of bacterial biofilm has potential value in delaying age-related pathology.

The hemolymph microbiome of insects

Hemolymph has long been recognized as a key mediator of nutritional and immunological homeostasis in insects, with the tacit understanding that hemolymph is a hostile environment for microorganisms, and microbiologically sterile in healthy insects. Recent research is overturning the conventional wisdom, and there is now overwhelming evidence that various non-pathogenic microorganisms can stably or transiently inhabit hemolymph in a diversity of insects. Most is known about Spiroplasma, especially in Drosophila species, and secondary symbionts of the Enterobacteriaceae, notably Hamiltonella defensa, in aphids. These bacteria require many nutrients, representing a likely drain on host nutritional resources, and they persist in the hemolymph by a combination of evasion and tolerance of insect immune effectors. These traits can be costly to the insect host. For some hemolymph microorganisms, these costs are balanced by other traits beneficial to the insect, notably protection against natural enemies mediated by specific toxins or competition for key nutrients. Three key priorities for future research are: to investigate the prevalence and taxonomic diversity of hemolymph microorganisms in insects; to establish the role of host nutritional and immune factors as determinants of the abundance and proliferation rates of hemolymph microorganisms; and to integrate the developing understanding of these microorganisms and their impacts (both costs and benefits) on insect nutrition and immune function into the wider study of insect physiology.

Periodontal Disease: A Risk Factor for Diabetes and Cardiovascular Disease

Periodontitis is a chronic inflammatory disease, initiated by the presence of a bacterial biofilm, called dental plaque, which affects both the periodontal ligaments and bone surrounding teeth. In the last decades, several lines of evidence have supported the existence of a relationship between periodontitis and systemic health. For instance, as periodontitis acts within the same chronic inflammatory model seen in cardiovascular disease (CVD), or other disorders, such as diabetes, several studies have suggested the existence of a bi-directional link between periodontal health and these pathologies. For instance, people with diabetes are more susceptible to infections and are more likely to suffer from periodontitis than people without this syndrome. Analogously, it is now evident that cardiac disorders are worsened by periodontitis, both experimentally and in humans. For all these reasons, it is very plausible that preventing periodontitis has an impact on the onset or progression of CVD and diabetes. On these grounds, in this review, we have provided an updated account on the current knowledge concerning periodontal disease and the adverse effects exerted on the cardiovascular system health and diabetes, informing readers on the most recent preclinical studies and epidemiological evidence.

Pyruvate-depleting conditions induce biofilm dispersion and enhance the efficacy of antibiotics in killing biofilms in vitro and in vivo

The formation of biofilms is a developmental process initiated by planktonic cells transitioning to the surface, which comes full circle when cells disperse from the biofilm and transition to the planktonic mode of growth. Considering that pyruvate has been previously demonstrated to be required for the formation of P. aeruginosa biofilms, we asked whether pyruvate likewise contributes to the maintenance of the biofilm structure, with depletion of pyruvate resulting in dispersion. Here, we demonstrate that the enzymatic depletion of pyruvate coincided with the dispersion of established biofilms by S. aureus and laboratory and clinical P. aeruginosa isolates. The dispersion response was dependent on pyruvate fermentation pathway components but independent of proteins previously described to contribute to P. aeruginosa biofilm dispersion. Using porcine second-degree burn wounds infected with P. aeruginosa biofilm cells, we furthermore demonstrated that pyruvate depletion resulted in a reduction of biofilm biomass in vivo. Pyruvate-depleting conditions enhanced the efficacy of tobramycin killing of the resident wound biofilms by up to 5-logs. Our findings strongly suggest the management of pyruvate availability to be a promising strategy to combat biofilm-related infections by two principal pathogens associated with wound and cystic fibrosis lung infections.

Sepsis: mechanisms of bacterial injury to the patient

In bacteremia the majority of bacterial species are killed by oxidation on the surface of erythrocytes and digested by local phagocytes in the liver and the spleen. Sepsis-causing bacteria overcome this mechanism of human innate immunity by versatile respiration, production of antioxidant enzymes, hemolysins, exo- and endotoxins, exopolymers and other factors that suppress host defense and provide bacterial survival. Entering the bloodstream in different forms (planktonic, encapsulated, L-form, biofilm fragments), they cause different types of sepsis (fulminant, acute, subacute, chronic, etc.). Sepsis treatment includes antibacterial therapy, support of host vital functions and restore of homeostasis. A bacterium killing is only one of numerous aspects of antibacterial therapy. The latter should inhibit the production of bacterial antioxidant enzymes and hemolysins, neutralize bacterial toxins, modulate bacterial respiration, increase host tolerance to bacterial products, facilitate host bactericidal mechanism and disperse bacterial capsule and biofilm.