TESTING


49


The accuracy of genome sequencing analysis depends on how well the sample handling and processing have been made


volunteers. In order to maintain a consistent standardized approach, a skin preparation period was foreseen at the start of the study. Clinical assessment has been performed


by the dermatologist who verified the skin compatibility of each volunteer based on skin examination of the experimental area looking for any physical signs (erythema, dryness etc.). The instrumental part was instead entrusted to the technician who assessed the cosmetic efficacy by the evaluation of skin TEWL (transepidermal water loss) with a Tewameter TM 300 (Courage & Khazaka), skin pH with Skin-pH-Meter PH 905 (Courage & Khazaka), skin greasiness using Sebumeter SM 815 (Courage & Khazaka) and skin moisturizing using Corneometer CM 825 (Courage & Khazaka). Moreover, the cosmetic qualities and


efficacy have been appreciated after analysis of a questionnaire adapted to the investigational product, validated by the sponsor and completed by each test subject. Microbiota sampling has been performed by the same technician in the delineated experimental area using sterile swabs at the inclusion and then after 28 consecutive days of product use. The swab heads have been stored at room temperature until use. The genomic DNA have been extracted


using an Ion 16S Metagenomics Kit (ThermoFisher Scientific), that uses two primers pool to amplify seven hypervariable regions (V2, V3, V4, V6, V7, V8 and V9) of bacterial 16S rRNA. The amplified fragments then have been sequenced and analysed. Since the healthy state of a tissue is


typically correlated to the increase in species diversity, we calculated it using three diversity indices: species richness (observed OTUs), Chao1 Index and Shannon Diversity Index. Observed operational taxonomic units


(OUT) richness index count the number of species in the community, not taking into account the relative abundances. The Chao1 Index estimates richness taking into account rare species, while the Shannon Diversity Index takes into consideration the abundance of each taxon and whether or not the distribution of OTUs in the sample is even.23


Conclusion In conclusion, the human skin microbiome has


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recently become a focus for cosmetic industries. Improving our understanding of host-microbial interactions and how to maintain its delicate balance is essential for the development of new cosmetic formulations. The integrated approach we propose aim to support the analysis of microbiome sequencing data by use of skin biophysical measurements. Currently, there is no standardised methodology to control effects of the status of microbiota before and after the application of active ingredient and this aspect will be an important future challenge.


PC


References 1. Sfriso R, Egert M, Gempeler M, Voegeli R, Campiche R. Revealing the secret life of skin – with the microbiome you never walk alone. International Journal of Cosmetic Science. 42, 116–126 (2020)


2. Moskovicz V, Gross A, Mizrahi B. Extrinsic Factors Shaping the Skin Microbiome. Microorganisms. 8(7): 1023 (2020)


3. Perez GI et al. Body Site Is a More Determinant Factor than Human Population Diversity in the Healthy Skin Microbiome. PLoS ONE. 11, e0151990 (2016)


4. Folster-Holst R. The role of the skin microbiome in atopic dermatitis – correlations and consequences. J Dtsch. Dermatol. Ges. 20(5):571-577. doi: 10.1111/ ddg.14709 (2022)


5. Hwang BK et al. Effect of the skincare product on facial skin microbial structure and biophysical parameters: A pilot study. Microbiologyopen. 10(5): e1236. doi: 10.1002/ mbo3.1236 (2021)


6. Capone KA et al. Diversity of the Human Skin Microbiome Early in Life. J. Invest. Dermatol. 131(10): 2026–2032 (2011)


7. Stamatas GN. Skin Microbiome Handbook: From Basic Research to Product Development. Nava Dayan (ed.). Chapter 6: Infant Skin Microbiome (2020)


8. Singh G, Archana G. Unrevealing the Mystery of Vernix Caseosa. Indian J. Dermatol. 53(2): 54-60 (2008)


9. Skowron K et al. Human Skin Microbiome: Impact of Intrinsic and Extrinsic Factors on Skin Microbiota. Microorganisms. 9(3): 543 (2021)


10. Luna PC. Skin Microbiome as Years Go By. Am. J. Clin Dermatol. 21(Suppl 1): 12-17 (2020)


11. Dréno B et al. Cutibacterium acnes (Propionibacterium acnes) and acne vulgaris: a brief look at the latest updates. JEADV. (2018)


12. Williams MR, Gallo RL. Evidence that Human Skin Microbiome Dysbiosis Promotes Atopic Dermatitis. J. Invest. Dermatol. 137(12):2460- 2461. Doi: 10.1016/j.jid.2017.09.010 (2017)


13. Hwang BK et al. Effect of the skincare product on facial skin microbial structure and biophysical parameters: A pilot study. Microbiologyopen. 10(5):e1236. doi: 10.1002/ mbo3.1236 (2021)


14. De Pessemier B et al. Gut–Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions. Microorganisms. 9(2): 353 (2021)


15. Whitney P Bowe, Alan C Logan. Acne vulgaris, probiotics and the gut-brain-skin axis - back to the future? Gut. Pathog. 3(1):1. doi: 10.1186/1757-4749-3-1 (2011)


16. Mahmud R et al. Impact of gut microbiome on skin health: gut-skin axis observed through the lenses of therapeutics and skin diseases. Gut Microbes. 14(1): 2096995 (2022)


17. Salem I et al. The Gut Microbiome as a Major Regulator of the Gut-Skin Axis. Frontiers in Microbiology. 9: 1459 (2018)


18. Bosman ES et al. Skin Exposure to Narrow Band Ultraviolet (UVB) Light Modulates the Human Intestinal Microbiome. Frontiers in Microbiology. 10: 2410 (2019)


19. Prescott SL et al. The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming. World Allergy Organ J. 10(1):29. doi: 0.1186/s40413-017-0160-5 (2017)


20. Paetzold B et al. Skin microbiome modulation induced by probiotic solutions. Microbiome. 7(1):95. doi: 10.1186/s40168-019- 0709-3 (2019)


21. Fricker AM, Podlesny D, Fricke WF. What is new and relevant for sequencing-based microbiome research? A mini-review. Journal of Advanced Research. 19: 105–112 (2019)


22. Kong HH et al. Performing Skin Microbiome Research: A Method to the Madness. J. Invest. Dermatol. 137(3):561-568. doi: 10.1016/j.jid.2016.10.033 (2017)


23. Finotello F, Mastrorilli E, Di Camillo B. Measuring the diversity of the human microbiota with targeted next-generation sequencing. Brief Bioinform. 19(4):679-692. doi: 10.1093/bib/bbw119 (2018)


November 2022 PERSONAL CARE


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