Is Skin Microbiota the Key to Chronic kidney disease and pruritus ?

Chronic kidney disease and pruritus, Patients with end-stage kidney disease (chronic kidney disease stage 5) frequently suffer from pruritus (itching), which significantly impacts their quality of life. Previous research has suggested that factors such as calcium-phosphorus (Ca-P) metabolism, dry skin, and inflammatory mediators are related to pruritus. However, the exact cause remains unclear. Recent studies propose that skin microbiota may be linked to pruritus in chronic kidney disease patients. But how exactly does skin microbiota influence itching?

What is Cutibacterium?

Cutibacterium is a gram-positive, anaerobic bacterium that is part of the skin’s natural microbiota. Formerly known as Propionibacterium acnes, it is now classified as Cutibacterium acnes.

Role of Cutibacterium in the Skin

Cutibacterium is primarily found in sebaceous gland-rich areas such as the face, chest, and back and plays a crucial role in maintaining skin health.

Skin Protection
- Cutibacterium breaks down lipids to produce short-chain fatty acids (SCFAs).
- It produces propionic acid and butyric acid, which lower skin pH and inhibit harmful bacteria such as Staphylococcus aureus.
- This helps prevent infections and maintains a healthy microbial balance.
Immune Regulation
- Cutibacterium modulates immune responses and has anti-inflammatory properties.
- It strengthens the skin barrier and reduces excessive inflammatory reactions.
Relationship with Acne
- While Cutibacterium is a normal part of the skin microbiome, excessive sebum production can turn it into a trigger for acne.
- Some strains can induce inflammation and, under specific conditions, lead to folliculitis and acne breakouts.

Consequences of Cutibacterium Reduction

Various factors, such as antibiotic use, excessive cleansing, and disease conditions, can lead to a decline in Cutibacterium levels, causing:

Increase in harmful bacteria: Overgrowth of Staphylococcus aureus and other pathogenic bacteria.
Worsening of skin conditions: Exacerbation of atopic dermatitis, eczema, and chronic pruritus.
Aggravation of pruritus in CKD patients: Recent studies suggest that reduced Cutibacterium levels are linked to pruritus in CKD stage 5 patients.

Study Overview: Skin Microbiota and Pruritus

A 2025 study published in Kidney Research and Clinical Practice examined 76 chronic kidney disease patients (40 on hemodialysis, 36 on peritoneal dialysis) and 15 healthy controls to analyze their skin microbiota. Researchers collected samples from three body regions:

Back
Antecubital fossa (inner elbow)
Shin

The microbial composition was analyzed using 16S rRNA gene sequencing, and pruritus severity was assessed using WI-NRS, the 5-D Itch Scale, and UP-Dial questionnaires.