Porphyromonas gingivalis and Its Systemic Impact: Current Status

Abstract

The relationship between periodontitis and systemic diseases, notably including atherosclerosis and diabetes, has been studied for several years. Porphyromonas gingivalis, a prominent component of oral microorganism communities, is the main pathogen that causes periodontitis. As a result of the extensive analysis of this organism, the evidence of its connection to systemic diseases has become more apparent over the last decade. A significant amount of research has explored the role of Porphyromonas gingivalis in atherosclerosis, Alzheimer’s disease, rheumatoid arthritis, diabetes, and adverse pregnancy outcomes, while relatively few studies have examined its contribution to respiratory diseases, nonalcoholic fatty liver disease, and depression. Here, we provide an overview of the current state of knowledge about Porphyromonas gingivalis and its systemic impact in an aim to inform readers of the existing epidemiological evidence and the most recent preclinical studies. Additionally, the possible mechanisms by which Porphyromonas gingivalis is involved in the onset or exacerbation of diseases, together with its effects on systemic health, are covered. Although a few results remain controversial, it is now evident that Porphyromonas gingivalis should be regarded as a modifiable factor for several diseases.

Possible effects of Porphyromonas gingivalis on the blood–brain barrier in Alzheimer’s disease

“…P. gingivalis can, in addition to increase BBB permeability, prevent the entry of immune cells into the brain and inhibit the local IFN-γ response [32]. This is consistent with the scarcity of adaptive immune cells detected in AD neuropathology and supports the notion that P. gingivalis can induce immune suppression in the brain [33].…”

Outer membrane vesicles of Porphyromonas gingivalis: Novel communication tool and strategy

“…Several mechanisms have been reported to associate P. gingivalis with these systemic diseases. P. gingivalis affects endothelial cells, platelets, leucocytes (mainly monocytes and macrophages), cardiomyocytes, and smooth muscle cells to aggravate cardiovascular diseases such as atherosclerotic cardiovascular diseases and myocardial infarction [ [8] , [9] , [10] ]. P. gingivalis enhances oxidative stress, inflammatory and prothrombotic responses in endothelial cells [ [11] , [12] , [13] ].…”

“…P. gingivalis LPS also is involved in obesity-associated insulin resistance by inducing pro-inflammatory adipokine production and oxidative stress in adipocytes [ 23 ]. P. gingivalis, reportedly, raises the development of oral squamous cell carcinoma, esophageal and pancreatic cancers through epithelial-mesenchymal transition (EMT) of oral epithelial cells, the prevention of epithelial cell apoptosis, and the promotion of immune evasion, etc [ 8 , [24] , [25] , [26] ]. P. gingivalis modulates EMT by regulating zinc-finger homeobox proteins (ZEB1 and Zeb2) and GSK-3β/β-catenin/forkhead box-O1 (FOXO1) [ 27 ].…”

“…P. gingivalis modulates EMT by regulating zinc-finger homeobox proteins (ZEB1 and Zeb2) and GSK-3β/β-catenin/forkhead box-O1 (FOXO1) [ 27 ]. Furthermore, P. gingivalis controls epithelial apoptosis many apoptotic/anti-apoptotic pathways including PI3K/Akt and JAK/Stat pathways as well as mitochondrial apoptosis-related factors (Bad, Bcl-2, and Bax) [ 8 , 26 , 28 ]. In the field of neurology, P. gingivalis infection has been suggested to be the risk of Alzheimaer’s disease (AD) and depression by several epidemiological studies [ 29 , 30 ].…”

CpG immunostimulatory oligodeoxynucleotide 1826 as a novel nasal ODN adjuvant enhanced the protective efficacy of the periodontitis gene vaccine in a periodontitis model in SD rats

“…Periodontitis is one of the most common oral diseases worldwide and leads to the destruction of periodontal tissue, mainly in the form of inflammation of the gingiva and alveolar bone loss [ 1 ]. Besides, periodontitis is a risk factor for various systemic diseases, including cardiovascular disease, diabetes, and osteoporosis [ 2 – 4 ]. The Gram-negative anaerobic bacterium Porphyromonas gingivalis ( P. gingivalis ) is one of the key pathogens in chronic periodontitis [ 5 ].…”