A triple-blind randomized clinical trial revealed that coconut oil may modulate the oral microbiome and reduce inflammatory markers in patients with periodontitis, suggesting its potential use as a natural adjunct to standard periodontal therapy.
In the study, published in Clinical Oral Investigations, researchers from multiple Spanish institutions—including Fundación Clínica Pardiñas, the Instituto de Investigación Biomédica de A Coruña (INIBIC), and Hospital Universitario de A Coruña—randomly assigned 30 patients diagnosed with stage II and III (grades B and C) periodontitis to three equal groups: coconut oil rinse, 0.12% chlorhexidine rinse, or placebo. Saliva and gingival crevicular fluid (GCF) samples were collected at baseline, 1 month following the initiation of the assigned mouth rinse, and 1 month following nonsurgical periodontal therapy.
"Coconut oil treatment significantly modulated the oral microbiome and reduced inflammatory markers in patients with periodontitis, suggesting its potential as a natural and effective adjunct in periodontal therapy," the study authors emphasized.
Using next-generation sequencing (NGS) and 16S rRNA metabarcoding, the researchers found that coconut oil reduced pathogenic bacterial families in the GCF, including Spirochaetaceae and Tannerellaceae, while promoting beneficial bacteria such as Streptococcaceae. At the species level, coconut oil treatment demonstrated notable reductions in periodontal pathogens like Tannerella forsythia and Treponema denticola.
The subgingival microbial dysbiosis index improved significantly in both the coconut oil and chlorhexidine groups, with a pronounced decrease observed between the second and third sampling points—demonstrating a shift toward a more balanced microbial profile.
Beyond its antimicrobial effects, coconut oil demonstrated anti-inflammatory properties. The coconut oil group showed a decrease in interleukin-6 levels over the entire study period (P = .02) and between the second and third sampling points when compared with placebo (P = .03). Similarly, a significant reduction in tumor necrosis factor-alpha was observed in the coconut oil group between the first and third sampling points (P = .02), with a statistically significant difference between coconut oil and chlorhexidine groups favoring coconut oil (P = .05).
For the study, the researchers selected a pure virgin coconut oil with the highest lauric acid content (47.92% C12:0) after analyzing four commercial oils using gas chromatography. The patients in the coconut oil group were instructed to rinse vigorously with 5 mL of oil for 10 minutes after brushing at night, whereas those in the chlorhexidine and placebo groups rinsed for just 1 minute. The researchers explained that coconut oil's antimicrobial properties derive primarily from its medium-chain fatty acids, particularly lauric acid.
"In the case of Gram-negative bacteria, the amphipathic nature of these compounds allows them to penetrate the bacterial membrane and form micelles that disrupt the membrane, leading to increased permeability, leakage of cell contents, and ultimately cell death," the study authors wrote.
Unlike chlorhexidine, which is linked to side effects such as tooth and tissue staining, taste alteration, and hypersensitivity reactions with prolonged use, coconut oil appeared to offer a natural alternative with minimal adverse effects.
The study's principal limitation was its relatively small sample size of 30 participants, indicating the need for larger-scale research to obtain more conclusive results.
The authors declared no competing interests.
