The effect of the “Oral-Gut” axis on periodontitis in inflammatory bowel disease: A review of microbe and immune mechanism associations

Abstract

Periodontitis and inflammatory bowel diseases (IBD) are inflammatory diseases of the gastrointestinal tract that share common features of microbial-induced ecological dysregulation and host immune inflammatory response. The close relationship between periodontitis and IBD is characterized by a higher prevalence of IBD in patients with periodontitis and a higher prevalence and severity of periodontitis in patients with IBD, indicating that periodontitis and IBD are different from the traditional independent diseases and form an “Oral-Gut” axis between the two, which affect each other and thus form a vicious circle. However, the specific mechanisms leading to the association between the two are not fully understood. In this article, we describe the interconnection between periodontitis and IBD in terms of microbial pathogenesis and immune dysregulation, including the ectopic colonization of the gut by pathogenic bacteria associated with periodontitis that promotes inflammation in the gut by activating the host immune response, and the alteration of the oral microbiota due to IBD that affects the periodontal inflammatory response. Among the microbial factors, pathogenic bacteria such as Klebsiella, Porphyromonas gingivalis and Fusobacterium nucleatum may act as the microbial bridge between periodontitis and IBD, while among the immune mechanisms, Th17 cell responses and the secreted pro-inflammatory factors IL-1β, IL-6 and TNF-α play a key role in the development of both diseases. This suggests that in future studies, we can look for targets in the “Oral-Gut” axis to control and intervene in periodontal inflammation by regulating periodontal or intestinal flora through immunological methods.

Genetic evidence strengthens the connection between gut microbiota and gingivitis: a two-sample Mendelian randomization study

“…liver cancer) progression by modifying underlying biological pathways, potentially guiding the development of targeted periodontal interventions for the disease prevention. In short, the pivotal role of gut microbiota in gingivitis and overall health underscores the potential for investigating targets along the “oral-gut axis” to manage inflammatory disorders, which may involve immunological approaches to regulate intestinal microbiota ( Zhou et al., 2023 ).…”

Genetic evidence strengthens the bidirectional connection between gut microbiota and periodontitis: insights from a two-sample Mendelian randomization study

“…Recently, potential mechanisms of intestinal bacteria mediating oral disease and overall health has been investigated [ 47 ]. On the one hand, ectopic colonization of periodontitis-associated pathobionts in the intestine induces intestinal inflammation and alters local homeostasis by activating both innate (e.g., macrophages) and adaptive (e.g., T helper-17 cells) immunity heterotopically via the “oral-gut axis” [ 6 , 7 ], which was also identified as a key link in the extra-oral comorbidity crosstalk, including inflammatory bowel disease (IBD) [ 48 ], Alzheimer's disease (AD) [ 49 ], nonalcoholic fatty liver disease (NAFLD) [ 50 ], colorectal cancer [ 51 ], hypertension [ 4 ], and arthritis [ 5 ]. Changes in the variety and quantity of intestinal microbiota induced by systemic disease, on the other hand, frequently coexist with extraintestinal symptoms in locations such as the oral cavity, which manifested as more severe loss of periodontal attachment and alveolar bone resorption in people with periodontitis [ 11 ].…”

“…Recent studies have highlighted the ‘‘oral-gut axis’’ in the interactions between oral and gut microbiota [ 4 , 5 ], which may be also involved in the crosstalk of periodontitis-mediated systemic inflammatory comorbidities [ 6 ]. Microbial dysregulation and immunological inflammatory responses induced by ‘‘oral-gut axis’’ alterations are common manifestations of periodontitis and multiple inflammatory comorbidities [ 7 ]. Specifically, periodontitis-associated pathobionts may influence the composition of intestinal microbiota by continuous saliva swallowing, hence impacting systemic diseases [ 8 , 9 ].…”

The Role of Vitamin C and Vitamin D in the Pathogenesis and Therapy of Periodontitis—Narrative Review

“…Research in recent years indicates that vitamins such as VitC and VitD are also involved in these processes. The newest research suggests that promising treatment strategies for periodontal disease should be based on therapies that target all molecular and cellular causes of disease development [ 69 ]. Despite the progress that has been made in the knowledge of the causes of periodontal disease, there is still a need to deepen our understanding of its pathogenesis.…”

“…The nonsurgical way consists of anti-inflammatory drug administration and microinvasive treatment, such as probing the periodontium. Various compounds, such as ozonized hydrogel or chlorhexidine gel, can also be used for antibacterial effects [ 69 , 70 ]. Another viable option is antimicrobial photodynamic therapy, where light-sensitive materials are used to produce concentrated free radicals which are toxic for the bacteria.…”