Written by Erin Yeh
Oral diseases have been linked to chronic kidney disease (CKD) due to inflammatory and microbial pathways that extend beyond the mouth. Research suggests a bidirectional relationship between gingivitis, also known as gum disease, and chronic kidney disease. Mainly, gingivitis can spread into the bloodstream, raising cytokine levels and damaging blood vessels, which can cause inflammation and accelerate kidney dysfunction. Furthermore, changes in the oral microbiome can allow harmful substances to enter the bloodstream, contributing to increased kidney damage.
Despite this association, most evidence comes from observational studies with modest effect sizes. Researchers from the University of Cincinnati College of Medicine reviewed evidence from more than 150 published papers, including observational studies, meta-analyses and international trials to identify growing evidence of the relationship between oral health and kidney health (Springer Nature LinkDigital ID: https://doi.org/10.1186/s12882-026-04843-y).
Various treadmills
“We know there is a relationship between chronic kidney disease (CKD) and oral disease,” said Priyanka Godsurkar, first author of the study and an assistant professor in the Department of Environmental Sciences and Public Health at the University of Cincinnati College of Medicine. In a press release. “Emerging evidence supports a bidirectional relationship.”
The team found that periodontal disease and chronic kidney disease are linked through a bidirectional network of immune, vascular, metabolic, and microbial pathways that mutually promote disease progression. In the mouth, when plaque builds up around teeth, the balance of the microbiome is disrupted, causing the immune system to react and release inflammatory signals. If this inflammation is long-lasting, bacteria and inflammatory molecules enter the bloodstream and spread the inflammation throughout the body. Over time, blood vessels become damaged, increasing oxidative stress and potentially contributing to kidney problems.
Chronic kidney disease also disrupts the immune system by building up toxins, weakening the ability of immune cells to fight infection and keeping the body in a constant low-level inflammatory state. This makes it more difficult to control the oral microbiome and also contributes to inflammation. As a result, gingivitis can develop more quickly, and a vicious cycle occurs.
However, it is not only the mouth and kidneys that affect each other. Chronic inflammation with persistent immune activity can lead to breakdown of the bone around the teeth and deterioration of the supporting tissue. When the lining of the periodontal pocket is damaged, bacteria and inflammatory particles can enter the bloodstream. Inflammation can reach the bone marrow, where the production of immune cells changes, releasing hyper-reactive cells that perpetuate inflammation throughout the body. In the kidney, elevated immune activity makes the tissue more vulnerable to damage by increasing immune cell accumulation, inflammation, and oxidative injury, thus accelerating the progression of chronic kidney disease.
Furthermore, chronic kidney disease worsens mineral and bone balance, while also contributing to hardening of blood vessels and weakening of bones. Damaged blood cells reduce healthy blood flow to the gums and kidneys, causing low oxygen levels, increased inflammation, and ongoing tissue damage. Evidence also shows that imbalances in minerals (such as calcium and phosphate) and parathyroid hormone levels are often associated with damage to the gums and oral tissues.
In advanced gum disease, neutrophils – key immune cells – do not function normally. They live longer than they should, produce excessive harmful molecules, and do not move efficiently to where they are needed. Instead of protecting tissues, these changes can cause further damage and even lead to immune-related problems. In the kidneys, overactive neutrophils and their byproducts can damage blood vessels, injure filtration structures, and promote inflammation in surrounding tissue.
An imbalance in bacteria and metabolism adds another layer to the relationship between gum disease and chronic kidney disease. In gum disease, harmful bacteria can interfere with immune defenses, and in chronic kidney disease, toxin buildup and other physical changes can disrupt the balance of the microbiome in the gut and mouth, weaken protective barriers, and change how bacteria function. These changes can allow bacteria to spread through the bloodstream and keep the body in a state of metabolic stress and inflammation, leading to further damage to the kidneys and gums.
Integrated care is needed
According to Gudsurkar Statement in the press releaseThere should be a “framework that supports the integration of oral and renal care across the continuum of chronic kidney disease.”
Non-surgical periodontal therapy (NSPT) has been shown to reduce systemic inflammation in patients with CKD, as well as lead to subtle improvements in kidney function and nutritional status in patients with end-stage kidney disease, the research team writes. Although it is still unclear whether these benefits can lead to long-term improvements in kidney outcomes, these results suggest that NSPT can at least reverse inflammation in chronic kidney disease.
Conversely, treatment of CKD may influence periodontal inflammation and disease course by improving immune competence, metabolic homeostasis, and vascular health. However, data on these outcomes are very sparse. Detoxification through intensive or appropriate dialysis can reduce inflammation and oxidative stress, as well as improve immune cell function. These changes may partially restore the antimicrobial defense of the gums and reduce gingivitis. In addition, treating anemia associated with chronic kidney disease and metabolic acidosis can improve tissue oxygen levels and balance local acidity levels, reducing inflammation and breakdown of gum tissue.
Some observational studies in dialysis and kidney transplant patients suggest that improved kidney function or toxin control is associated with stable or slightly better periodontal health, but results vary, especially in kidney transplant patients receiving immunosuppressive therapy. In addition, more oral complications may appear after starting dialysis, such as gingival overgrowth, small bleeding spots, and weak jaw bones. Dental care should be carefully timed around dialysis sessions and adjusted to take blood-thinning medications into account, the team writes. Incidentally, other conditions that cause chronic kidney disease, such as diabetes, can independently worsen gum disease.
But what stops integrated care?
Chronic kidney disease is expected to be the leading cause of years of loss of life by 2040 and is expected to cost $130 billion in medical care. Globally, approximately 80% of affected individuals live in low- and middle-income countries, where delayed diagnosis, lack of resources for health systems, and limited preventive strategies accelerate disease progression. Women also experience higher rates of untreated tooth decay and delayed diagnosis of chronic kidney disease. However, integrated care, despite its emergence, remains fragmented across regions.
Cultural perceptions of oral health as more cosmetic than medical may hinder integration and remain limited by limited community health knowledge. Even the World Health Organization lacks indicators linking stomatitis to kidney or cardiovascular problems. There are still no clear and uniform guidelines for dental care, especially for patients awaiting a kidney transplant. Surveys show that there are wide variations in how pre-implantation dental examinations are performed, how infections are managed, and whether prophylactic antibiotics are used.
Fortunately, some countries have frameworks linking nephrology and dentistry services. For example, in Japan, routine oral assessments are part of dialysis treatment. Brazil also has a prevention education program for high-risk populations that integrates management of oral diseases and chronic diseases.
How to progress in integrated treatment
To make progress in integrated treatment for oral and kidney health, the research team has presented some methods. Electronic health records (EHRs) can play a critical role in integrating verbal assessments into the CKD workflow. Electronic health records and machine learning algorithms can identify oral dysfunction as an early indicator of deteriorating kidney function.
Interprofessional education is also the basis for sustainable integration. Curricula that combine the specializations of nephrology, dental hygiene, and public health improve students’ self-efficacy and collaborative readiness, the research team wrote. It also encourages integrated residency or fellowship programs that bridge oral medicine and nephrology to improve patient continuity and safety.
Research also shows that patients with chronic kidney disease have unique patterns of oral bacteria. This opens the opportunity to use saliva tests to help diagnose and monitor diseases through specific biomarkers and predictive tools. At the same time, genomics and bioinformatics have identified common inflammatory pathways between periodontal disease, kidney disease, and cardiovascular disease, reinforcing the need for personalized treatment and targeted therapy.
Community-based programs and telehealth models show a reduction in overall inflammation and improved patient outcomes by supporting coordinated care between oral and kidney health care providers. These multidisciplinary informatics-based innovations underscore the feasibility and clinical value of incorporating oral health into routine nephrology practice, which is practical and beneficial, especially for vulnerable and underserved populations.
The team urges more research to understand how gingivitis, changes in the oral microbiome, and immune system activation are biologically linked to kidney-related outcomes, such as organ transplant rejection, protein in the urine, and cardiovascular complications. This type of research will provide the basis for clear clinical guidelines and more personalized methods for assessing risk in people with chronic kidney disease. The research team also encourages the study of real-world barriers to facilitate adaptation and broader implementation of integrated care models. Improving the interoperability of electronic medical records can streamline monitoring of oral systemic risk factors, automate dental referrals, and enhance shared care planning between nephrology and dentistry specialists.
More long-term studies and well-designed trials are needed to determine whether periodontal treatment directly improves kidney health and how effective the benefits are. Future research should also focus on how current knowledge can be applied in real-world settings so that effective strategies can be put into practice, improve patient outcomes, and promote equitable and comprehensive care.
