Comparison of Oily/Dry Dandruff scalp: Clinical, Instrumental and Targeted Metagenomic Data
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Presented by: Sandrine Bessou Touya
Background/aims
Oily dandruff (OD) is associated to high sebum production and inflammation, yellowish and sticky flakes adherent to the scalp and hair and dysbiosis microbiota. Dry dandruff (DD) is in the form of small, whitish flakes, not adherent to the scalp and can be associated with itching and dry scalp. If OD’s Microbiota is well characterized, nothing is published about DD microbiota. Scalp microbiota is characterized by the presence of Malassezia, Cutibacterium and Staphylococcus genus. The aim of this study was to compare DD scalps’ clinical, instrumental and targeted metagenomic data versus OD scalps. Is DD microbiota dysbiosis have the same microorganism’s actors than OD one? If microbiota is different between DD and OD scalp, it could justify the development of adapted product to each type of scalp dandruff
Study design/methods
One study with 33 subjects (16 OD subjects and 17 DD subjects) with mild to moderate scaly state was done. For both population (OD and DD), clinical dandruff condition on whole scalp using clinical 10 -point-scale was assessed, itching and discomfort sensations were auto-assessed by subjects. Were instrumentally measured on scalp, hydration with Dermalab®, Lipid Index (IL) with Sebumeter® pH with pHmeter®and Trans Epidermal Water loss with Aquaflux®.
Scalp swabs were sampled from both groups for genomic DNA extraction and NGS sequencing. After microorganisms’ identification or absolute quantification of specific strains, different statistical analysis were run. Statistical analysis was done by Student’s T-Test. For metagenomic, differential analysis was used to identify genus or species more abundant in one group than the other.
Results
Dandruff score, itching and discomfort of scalp data were not significantly different between OD and DD scalp. pH of scalp was not different between OD and DD. Hydration and IL data of scalp were significantly higher for OD in comparison with DD. TEWL data were significantly higher in DD population.
Differential analysis of microbiota from the two groups showed the following significant differences: (i) OD scalps’ mycobiota is characterized by unknown species of Malasseziales order while Filobasidium genus are more present on DD scalps, (ii) Cutibacterium and Staphylococcus genus dominate OD and DD scalps’ bacteria populations. (iii) under-represented microorganisms’ communities are different between OD and DD states. Pelomonas, Capnocytophaga or Ralstonia genus are more present on DD scalps while Brachybacterium are preferentially observed on OD scalps.
Absolute quantification results underline M. restricta is associated with OD scalps.
Conclusion
According to published data, dehydration and low sebum production are characteristic of DD scalps while OD scalps display high sebum production and inflammation. Our results confirm the previous findings. Interestingly, the function barrier of the skin scalp seems to be more impaired in DD scalp. In addition, we have shown here that scalp microbiota of these two dandruff states are different. These results highlight the importance to address DD and OD scalps with specific scalp care products.
Oily dandruff (OD) is associated to high sebum production and inflammation, yellowish and sticky flakes adherent to the scalp and hair and dysbiosis microbiota. Dry dandruff (DD) is in the form of small, whitish flakes, not adherent to the scalp and can be associated with itching and dry scalp. If OD’s Microbiota is well characterized, nothing is published about DD microbiota. Scalp microbiota is characterized by the presence of Malassezia, Cutibacterium and Staphylococcus genus. The aim of this study was to compare DD scalps’ clinical, instrumental and targeted metagenomic data versus OD scalps. Is DD microbiota dysbiosis have the same microorganism’s actors than OD one? If microbiota is different between DD and OD scalp, it could justify the development of adapted product to each type of scalp dandruff
Study design/methods
One study with 33 subjects (16 OD subjects and 17 DD subjects) with mild to moderate scaly state was done. For both population (OD and DD), clinical dandruff condition on whole scalp using clinical 10 -point-scale was assessed, itching and discomfort sensations were auto-assessed by subjects. Were instrumentally measured on scalp, hydration with Dermalab®, Lipid Index (IL) with Sebumeter® pH with pHmeter®and Trans Epidermal Water loss with Aquaflux®.
Scalp swabs were sampled from both groups for genomic DNA extraction and NGS sequencing. After microorganisms’ identification or absolute quantification of specific strains, different statistical analysis were run. Statistical analysis was done by Student’s T-Test. For metagenomic, differential analysis was used to identify genus or species more abundant in one group than the other.
Results
Dandruff score, itching and discomfort of scalp data were not significantly different between OD and DD scalp. pH of scalp was not different between OD and DD. Hydration and IL data of scalp were significantly higher for OD in comparison with DD. TEWL data were significantly higher in DD population.
Differential analysis of microbiota from the two groups showed the following significant differences: (i) OD scalps’ mycobiota is characterized by unknown species of Malasseziales order while Filobasidium genus are more present on DD scalps, (ii) Cutibacterium and Staphylococcus genus dominate OD and DD scalps’ bacteria populations. (iii) under-represented microorganisms’ communities are different between OD and DD states. Pelomonas, Capnocytophaga or Ralstonia genus are more present on DD scalps while Brachybacterium are preferentially observed on OD scalps.
Absolute quantification results underline M. restricta is associated with OD scalps.
Conclusion
According to published data, dehydration and low sebum production are characteristic of DD scalps while OD scalps display high sebum production and inflammation. Our results confirm the previous findings. Interestingly, the function barrier of the skin scalp seems to be more impaired in DD scalp. In addition, we have shown here that scalp microbiota of these two dandruff states are different. These results highlight the importance to address DD and OD scalps with specific scalp care products.