Applications of Strain-Specific Probiotics in the Management of Cardiovascular Diseases: A Systemic Review

Cardiovascular diseases (CVDs) are a leading cause of global mortality and novel approaches for prevention and management are needed. The human gastrointestinal tract hosts a diverse microbiota that is crucial in maintaining metabolic homeostasis. The formulation of effective probiotics, alone or in combination, has been under discussion due to their impact on cardiovascular and metabolic diseases. Probiotics have been shown to impact cardiovascular health positively. An imbalance in the presence of Firmicutes and Bacteroidetes has been linked to the progression of CVDs due to their impact on bile acid and cholesterol metabolism. The probiotics primarily help in the reduction of plasma low-density lipoprotein levels and attenuation of the proinflammatory markers. These beneficial microorganisms contribute to lowering cholesterol levels and produce essential short-chain fatty acids. The impact of lipid-regulating probiotic strains on human health is quite significant. However, only a few have been tested for potential beneficial efficacy, and ambiguity exists regarding strain dosages, interactions with confounding factors, and potential adverse effects. Hence, more comprehensive studies and randomized trials are needed to understand the mechanisms of probiotics on CVDs and to ensure human health. This review assesses the evidence and highlights the roles of strain-specific probiotics in the management of CVDs.

Analysis of the blood bacterial composition of patients with acute coronary syndrome and chronic coronary syndrome

Emerging evidence revealed that the blood microbiota plays a role in several non-communicable diseases, including cardiovascular disease. However, the role of circulating microbes in atherosclerosis remains understudied. To test this hypothesis, we performed this study to investigate the microbial profile in the blood of Chines atherosclerosis volunteers. A total of seventy Acute Coronary Syndrome patients, seventy Chronic Coronary Syndrome patients, and seventy healthy individuals were examined using high-throughput Illumina Novaseq targeting the V3-V4 regions of the 16S rRNA gene. The relationship between atherosclerosis and blood microbiome, clinical variables, and their functional pathways were also investigated. Our study observed significantly higher alpha diversity indices (Chao1, p = 0.001, and Shannon, p = 0.004) in the acute coronary syndrome group compared with chronic coronary syndrome and healthy group, although a significantly lower alpha diversity was observed in the chronic coronary syndrome compared to acute coronary syndrome and healthy group. Beta diversity based on principal coordinate analysis demonstrated a major separation among the three groups. In addition, using linear discriminant analysis, a significant distinct taxon such as Actinobacteria _ phylum, and Staphylococcus_ genus in the healthy group; Firmicutes_ phylum, and Lactobacillus_ genus in the chronic coronary syndrome group, and Proteobacteria and Acidobacteriota _ phyla in acute coronary syndrome group were observed among three groups. Clusters of Orthologous Genes grouped and Kyoto Encyclopedia of Genes and Genomes pathways suggested a significant variation among all groups (p < 0.05). The blood microbiota analysis provides potential biomarkers for the detection of coronary syndromes in this population.

Low levels of antibodies for the oral bacterium Tannerella forsythia predict cardiovascular disease mortality in men with myocardial infarction: A prospective cohort study

Antibody levels to periodontal pathogens in prediction of cardiovascular disease (CVD) mortality were explored using data from a health survey in Oslo in 2000 (Oslo II-study) with 12 1/2 years follow-up. IgG antibodies to four common periodontal pathogens; Tannerella forsythia (TF), Porphyromonas gingivalis (PG), and Treponema denticola (TD) all termed collectively the "red complex", and Aggregatibacter actinomycetemcomitans(AA) were analysed. The study sample consisted of 1172 men drawn from a cohort of 6,530 men who participated in the Oslo II-study, where they provided information on medical and dental history. Of the study sample, 548 men had reported prior myocardial infarction (MI) at baseline whereas the remaining 624 men were randomly drawn from the ostensibly healthy participants for comparative analyses. Dental anamnestic information included tooth extractions and oral infections. An inverse relation was found for trend by the quartile risk level of TF predicting CVD mortality, p-value for trend = 0.017. Comparison of the first to fourth quartile of TF antibodies resulted in hazard ratio (HR) = 1.82, 95% confidence interval 1.12-2.94, p = 0.015, adjusted for age, education, diabetes, daily smoking, and systolic blood pressure. Specificity comparing decile 1 to deciles 2-10 of TF predicting mortality was 92.3%. We found an increased HR by low levels of antibodies to the bacterium T. forsythia predicting CVD mortality in a 12 ½ years follow-up in persons who had experienced an MI but not among non-MI men. This novel finding constitutes a plausible causal link between oral infections and CVD mortality.

Association between Alzheimer's Disease and Oral and Gut Microbiota: Are Pore Forming Proteins the Missing Link?

Alzheimer's disease (AD) is a neurodegenerative condition affecting millions of people worldwide. It is associated with cerebral amyloid-β (Aβ) plaque deposition in the brain, synaptic disconnection, and subsequent progressive neuronal death. Although considerable progress has been made to elucidate the pathogenesis of AD, the specific causes of the disease remain highly unknown. Recent research has suggested a potential association between certain infectious diseases and dementia, either directly due to bacterial brain invasion and toxin production, or indirectly by modulating the immune response. Therefore, in the present review we focus on the emerging issues of bacterial infection and AD, including the existence of antimicrobial peptides having pore-forming properties that act in a similar way to pores formed by Aβ in a variety of cell membranes. Special focus is placed on oral bacteria and biofilms, and on the potential mechanisms associating bacterial infection and toxin production in AD. The role of bacterial outer membrane vesicles on the transport and delivery of toxins as well as porins to the brain is also discussed. Aβ has shown to possess antimicrobial activity against several bacteria, and therefore could be upregulated as a response to bacteria and bacterial toxins in the brain. Although further research is needed, we believe that the control of biofilm-mediated diseases could be an important potential prevention mechanism for AD development.

Age and Age-Related Diseases: Role of Inflammation Triggers and Cytokines

Cytokine dysregulation is believed to play a key role in the remodeling of the immune system at older age, with evidence pointing to an inability to fine-control systemic inflammation, which seems to be a marker of unsuccessful aging. This reshaping of cytokine expression pattern, with a progressive tendency toward a pro-inflammatory phenotype has been called "inflamm-aging." Despite research there is no clear understanding about the causes of "inflamm-aging" that underpin most major age-related diseases, including atherosclerosis, diabetes, Alzheimer's disease, rheumatoid arthritis, cancer, and aging itself. While inflammation is part of the normal repair response for healing, and essential in keeping us safe from bacterial and viral infections and noxious environmental agents, not all inflammation is good. When inflammation becomes prolonged and persists, it can become damaging and destructive. Several common molecular pathways have been identified that are associated with both aging and low-grade inflammation. The age-related change in redox balance, the increase in age-related senescent cells, the senescence-associated secretory phenotype (SASP) and the decline in effective autophagy that can trigger the inflammasome, suggest that it may be possible to delay age-related diseases and aging itself by suppressing pro-inflammatory molecular mechanisms or improving the timely resolution of inflammation. Conversely there may be learning from molecular or genetic pathways from long-lived cohorts who exemplify good quality aging. Here, we will discuss some of the current ideas and highlight molecular pathways that appear to contribute to the immune imbalance and the cytokine dysregulation, which is associated with "inflammageing" or parainflammation. Evidence of these findings will be drawn from research in cardiovascular disease, cancer, neurological inflammation and rheumatoid arthritis.