The Mouth and the Kidney - relationships to remember
- docbinah
- Dec 21, 2025
- 8 min read
Updated: Dec 23, 2025
Robin Rose MD Winter Solstice 2025
Let us begin with an imaginary cartoon of “the kidney bone is connected to the mouth bone.”
Our goal - understanding how the health of the kidneys depends on the health of the mouth and vice versa. Bidirectional.
Let’s set the stage: CKD is a systemic inflammatory state; the oral cavity is a persistent inflammatory source.
We have a “vicious cycle” and we aim to create a precious cycle of health [actually there is a “vicious triangle” of oral dysbiosis, systemic inflammation, and progressive tubular fibrosis].
There is a strong relation between periodontal diseases and chronic kidney disease (CKD). The main mechanisms at the base of this link are malnutrition, vitamin dysregulation, [especially vitamins B, C and D] oxidative stress, metabolic acidosis and low-grade inflammation.
Altered nutritional status in CKD leads to known systemic manifestations with repercussions on oral health
🌿oral microbiota dysbiosis
🌿slow wound healing due to hypovitaminosis C
🌿altered bone structures of the oral cavity related to:
🌿 metabolic acidosis
🌿deranged phosphorus
🌿vitamin D deficiency
Low-grade inflammation has been observed to characterize periodontal diseases locally and, in a systemic manner, CKD contributes to the amplification of the pathological process, bidirectionally.
We know about the cardio-oral health connection -
I will introduce you to the kidney-oral health axis.
🌿loss of kidney function causes oral manifestations
🌿up to 77% of CKD patients have alterations of normal oral cavity
🌿oral health is too often neglected in CKD patients
🌿 oral health commitment prevents opportunistic infections in CKD
🌿increased urea levels in the oral environment of CKD patients leads to many oral alterations
🌿uremic stomatitis and halitosis
🌿altered salivary composition and pH
🌿xerostomia
🌿dysgeusias
🌿pale oral mucosa
🌿oral mucosal pigmentation
🌿intensified periodontal disease
🌿dental enamel hypoplasia
🌿Shared mechanisms include: 🌿chronic endotoxemia
🌿inflammasome activation
🌿oxidative stress
🌿acidosis
🌿vitamin dysregulation
🌿protein-energy wasting
🌿shared risk factors (diabetes, smoking, poverty, low health literacy).
Altered Nutritional Assessment induces systemic manifestations that have repercussions on oral health
🌿oral microbiota dysbiosis
🌿slow wound healing - due to hypovitaminosis C
🌿alterations of the supporting bone structures the oral cavity are related to metabolic acidosis and vitamin D deficiency of CKD
🌿low grade inflammation occurs locally in periodontal disease and systemically when CKD amplifies the pathology
Assessment Pearls
Oral Concerns
🌿history
🌿dry mouth - day versus night
🌿taste change
🌿bleeding gums
🌿oral sores
🌿tongue pain/burning
🌿denture fit
🌿halitosis
🌿poor oral hygiene [leads to infections that harm kidney]
🌿Exam
🌿calculus
🌿candidiasis
🌿uremic fetor
🌿mucosal changes
Dysbiosis in CKD:
🌿the microbiome in the oral cavity plays a very important role in the health of the host - and it is altered in CKD [this changed microbial diversity is noted in the gut as well]
🌿take home message - treat local disease and address the the systemic terrain [dietary acid load, omega-3s, glycemic control]
🌿research has shown CKD reshapes the saliva composition and oral microbiome -> uremic biochemistry leads to progressive dysbiosis
🌿distinct salivary microbiomes are reported in CKD
🌿kidney injury can precipitate oral shifts
🌿the bacterial community is skewed in the saliva of CKD
🌿increased Lautropia and Pseudomonas
🌿decreased Actinomyces, Prevotella, Prevotella 7, Trichococcus
Periodontitis is common in CKD
🌿there is a known strong relation between periodontal diseases and CKD.
🌿The main mechanisms:
🌿malnutrition
🌿vitamin dysregulation
🌿especially B vitamins
🌿vitamins C and D
🌿oxidative stress
🌿metabolic acidosis
🌿low-grade inflammation.
🌿contributes to systemic inflammation - which increases inflammation in the nephrons
🌿treating periodontitis will lower the C-reactive protein and IL-6, which in turn will nudge the eGFR to improve
CKD biochemistry [urea → ammonia] and xerostomia reshape the oral microbiome
🌿intervention includes ecological restoration - not simply antisepsis
Xerostomia Awareness and Care - 28-74.2% prevalence in CKD cohorts
🌿Saliva plays an important role in kidney health
🌿oral microbiome signaling
🌿nitrogen balance
🌿uremic toxin excretion
🌿Salivary changes reflect & exacerbate system dysfunction
🌿associated with taste loss - poor appetite and malnutrition risk
🌿 increased Candida risk
🌿Supportive Strategies
🌿Alkalinize the microenvironment
🌿Xylitol gum/lozenges or rinses
🌿frequent sips of filtered or bicarbonate-enriched water
🌿bedroom humidifier
🌿taping the mouth during sleep
🌿evaluate medications [anticholinergics, loop diuretics]
🌿CoQ10/ubiqunone - improves gingival mitochondrial function
🌿Alpha Lipoic Acid - improves microvascular perfusion & neuropathic dry mouth
🌿Omega 3-fatty acids [DHS/EPA] - to reduce inflammatory salivary cytokines and enhance mucosal healing
🌿Probiotic lozenges/sprays - improve oral ecology
🌿Oil pulling with sesame/coconut oil - reduce uremic halitosis and biofilm load
🌿Melatonin - enhances salivary gland antioxidant defense and circadian flow rhythms, useful to autonomic regulation of sleep
STARTING EARLY - Stage 2 CKD
🌿The kidney tubule is the body’s oral mucosa turned inward !
Both surfaces regulate filtration, absorption, and microbial dialogue.
🌿Stage 2 - eGFR 60-90 - already shows epithelial micro-lesions - detectable through subtle oral and urinary changes
🌿Restoration is possible - core preventive Renology
🌿redox balance
🌿microbiome ecology
🌿epithelial integrity
🌿proximal tubular cells are already showing evidence of oxidative stress, mitochondrial injury, and impaired re-absorption of low molecular weight proteins and vitamins
🌿beta 2-microglobulin
🌿retinol binding protein
🌿vitamin D metabolites
🌿 even before we see a rise in creatinine, this series of subtle leaks disturbs the systemic homeostasis
🌿25-OH-vitamin D activation -> immune dysregulation +oral barrier weakness
🌿increased uremic solutes -> endothelial dysfunction +impaired salivary gland secretion
🌿 expression of tubular MCP-1, KIM-1, and NGAL reflects micro-inflammation that parallels oral inflammatory cytokine load [IL:-6, TNFa, IL-1B]
Tubular microenvironment mirrors the gingival sulcus - both are epithelial barriers dependent on
🌿mitochondrial integrity
🌿tight junctions
🌿balanced microbiota
Oral Manifestations of Early Kidney Tubular Decline
Even the earliest mildest decline in tubular function alters saliva composition and oral ecology:
🌿Urea accumulation -> alkaline saliva, with ammonia formation favoring urease-positive dysbiosis [Actinomyces, Veillonella]
🌿Reduced flow due to salivary gland microvascular damage:
🌿dry mouth
🌿fissured tongue
🌿impaired remineralization
🌿Micronutrient losses [B vitamins, zinc, magnesium] due to tubular wasting and failed reabsorption leading to
🌿glossitis
🌿delayed mucosal healing
🌿taste changes
🌿Inflammatory cytokine spillover from tubules contributes to periodontal tissue catabolism - the inside-out inflammatory echo
Shared Barriers: the Gingiva and the Tubule
Both the oral epithelium and the renal tubular epithelium depend on claudin/occludin based tight junction and mitochondrial redox balance.
🌿Endotoxemia from the mouth raises MCP-2 and TGF-B -> fibrosis
🌿Deficient Klotho signaling is associated with early tubular biomarker loss -> this compromises antioxidant defense, which increases oral oxidative stress.
Periodontitis is common in CKD
🌿contributes to systemic inflammation - which increases inflammation in the nephrons
🌿treating periodontitis will lower the C-reactive protein and IL-6, which in turn will nudge the eGFR to improve
CKD biochemistry [urea→ammonia] and xerostomia reshape the oral microbiome
🌿intervention includes ecological restoration - not simply antisepsis!
Big takeaways - remember this!
Bidirectional link: CKD worsens oral health (periodontitis, xerostomia, dysbiosis), and periodontitis associates with faster CKD progression and higher mortality—especially cardiovascular mortality.
Treating periodontal disease may improve kidney-relevant endpoints (e.g., eGFR, systemic inflammation), though RCT quality is mixed and effect sizes vary.
Mechanisms are plausible and overlapping: chronic endotoxemia, inflammasome activation, oxidative stress, acidosis, vitamin dysregulation, protein-energy wasting, and shared risk factors (diabetes, smoking, poverty, low health literacy).
Clinically useful: what to do in practice
Screen & stratify
In every CKD stage, getting a thorough history helps
ask about bleeding gums, tooth mobility, halitosis, xerostomia, painful chewing, and denture fit;
look for pocketing, plaque/calculus, mucosal lesions, uremic fetor. Dial in the message that albuminuria + reduced eGFR = higher oral risk.
Build a periodontal-kidney care loop
Early referral for dental/hygiene care and then to periodontics/hygiene for anyone with CKD beginning in stage 2 - especially when signs of periodontitis or diabetes-CKD overlap.
Emphasize inflammation reduction as a renal goal.
Lab tests to recheck
Clinical Markers to Track - early diagnosis and prompt correction means we can prevent the “vicious triangle” of oral dysbiosis, systemic inflammation, and *progressive tubular fibrosis
🌿Urinary testing to assess for tubular stress
🌿uNGAL
🌿uKIM-1
🌿uBeta-2 microglobulin
🌿uRetinol Binding
🌿Serum testing to assess systemic and oral inflammatory burden
🌿Cystatin C and eGFR
🌿urinalysis with ACR added
🌿CRP
🌿IL-6
🌿MCP-1
🌿Salivary pH, flow and oral microbiome testing
Low Risk nature-forward Interventions
🌿green tea rinses - rinse with brewed and cooled green tea as mouthwash
🌿arginine dentifrices
🌿xylitol
🌿S. Salivarius K12
🌿curcumin gel
🌿omega-3 - EPA/DHA
Mitochondrial and Antioxidant Support
🌿Carnosine - scavenges carbonyl stress and supports epithelial mitochondria → protective in tubular and gingival models
🌿CoQ10/ubiquinone - improves periodontal parameters and tubular antioxidant status
🌿Alpha lipoic acid - similarly supports antoxidant needs
🌿Polyphenols - green tea, pomegranate, curcumin: suppress NF-kB and MCP-1 both renally and orally
Oral Microbiome Restoration
🌿Green tea catechin or propolis rinses - rebalance oral flora without damaging commensals
🌿Probiotic S. Salivarius K12/M18 improves oral immunity and indirectly reduces systemic endotoxemia that can lead to tubulointerstitial inflammation
Nutrient Repletion: Tubule + Mucosa
🌿 monitor and correct
🌿zinc
🌿vitamin C
🌿vitamin D3 [impaired activation starts in Stage 2]
🌿PLP [activated B6] - for trans-sulfuration and antioxidant enzyme function [relevant to both tissues]
🌿phosphorss control: preserves tubule integrity while reducing oral calculus formation
Diet and Terrain
🌿PLADO diet - plant dominant, low-acid, lower protein:
🌿lowers net endogenous acid load
🌿preserves proximal tubular function
🌿preserves oral pH stability
🌿polyphenol-rich plants
🌿arginine sources
🌿omega-3
🌿Restrict phosphorus/phosphate additives
🌿limit and restrict fructose
🌿Prefer acetaminophen for dental pain in CKD [avoid routine NSAIDs]. Local anesthetics can be generally fine.
🌿If antibiotics are required, dose-adjust renally (e.g., amoxicillin, amox-clav, clindamycin per renal function), and coordinate for dialysis timing. (General CKD practice guidance.)
Lifestyle Medicine for Kidney and Oral Health
🌿Hydration - personalized case by case
🌿Diet
🌿anti-inflammation diet
🌿protein intake - personalize to CKD status - 0.8grams/kg for most is optimal to protect
🌿decrease fermentable sugar frequency
🌿polyphenol rich whole foods
🌿Prioritize
🌿glycemic control
🌿smoking cessation
🌿hydration
🌿Home Mouth Care
🌿Brushing after every meal
🌿floss/water floss
🌿water pik
🌿rinses
🌿Remineralization and pH strategies - focus on biofilm ecology
🌿Arginine dentifrices - 1.5-8% :
🌿 enhance alkali generation [arginine deaminase system]
🌿promotes healthier biofilm
🌿 reduces caries [beyond fluoride in trials - CKD safer]
🌿used when urea-rich/alkaline saliva flow is low
🌿Xylitol [gum, lozenges] - spaced through the day
🌿stimulates saliva - useful in xerostomia
🌿some evidence of reduced caries
🌿 GI tolerance must be monitored
🌿Biotics and botanicals to use locally
🌿green tea catechin rinse - Camellia sinensis
🌿reduces plaque/gingivitis - halitosis benefits
🌿substitute for chlorhexidine to protect microbiome
🌿brewed cooled rinses replace commercial products
🌿curcumin gels:
🌿improve periodontal parameters
🌿favorable safety profile
🌿oral probiotics [Strep salivarius K12/M18]:
🌿support colonization resistance against oral pathogens
🌿improved salivary immune markers and URTI reduction
🌿useful in xerostomic CKD patients prone to candidiasis/dysbiosius
Peptide Bioregulator Insight
🌿Russian scientists gave us a remarkable tool of ultra-small peptides [2-7 amino acid chains] that are well-studied and offer repair of epigenetic damage at the DNA level by working on chromatin and histones.
🌿Data shows:
🌿restoration of epithelial antioxidant enzymes
🌿normalization of epithelial gene expression
🌿reduced tubular cytokine spillover that feeds oral inflammation
🌿Examples:
🌿Pielotax - sourced from renal cortex
🌿Vilon - synthesized formulation of thymus
🌿Chonluten - cartilage
🌿Stomach bioregulator
CONCLUSION
The mouth bone is connected to the kidney bone - honor creation with a mindfulness that cares about what goes in and what comes out of the mouth. Kidney Success is our goal and finding the path to self-loving discipline is really one handle to the world of wellness.
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