An investigation into the potential mechanisms that drive gender based differences in skin microbiota

Transcription

1 An investigation into the potential mechanisms that drive gender based differences in skin microbiota Laura S. Weyrich, PhD Australian Centre for Ancient DNA University of Adelaide, Australia

2 More than skin deep Up to 35 million microbes per square centimetre! Distinct and diverse communities extend into dermis, below basal membrane Grice and Segre, Nature Reviews Microbiology, 2011 T. Nakatsuji, et al., Nature Communications, 2013

3 Interactions between the skin microbiota and immunity Physical defence from invading pathogens Antimicrobial and bacterial competition to limit pathogen colonization Aid in skin shedding Established immune tolerance Chen and Tsao, J. Am. Acad Dermatology, 2013

4 Disease Associations with skin microbial communities Skin Diseases Atopic dermatitis Psoriasis Acne vulgaris Chronic wounds Systemic Diseases Atopic sensitization Reviewed in Weyrich, et al., Australasian Journal of Dermatology, 2015 WebMD.com

5 Using NGS to investigate skin microbiota Initial HMP studies: Highly variable Highest levels of intrapersonal variability over time Costello et al., Science 326:1694, 2009

6 Mirrored diversity driven by physiology Unique body sites harbour unique microbiota Largely driven by physiology and host microorganisms Sebum production Moisture ph Others Costello et al., Science 326:1694, 2009

7 Fungal and bacterial communties are equally impacted Fungal communities are driven by similar factors M. restricta (i; ρ = 0.92) and M. globosa (a; ρ = 0.79) are primary and opposing drivers of variation Propionibacterium (j; ρ = 0.95) contributes to sebaceous site variation; Corynebacterium (l; ρ = 0.74) and Turicella (q; ρ = 0.56) contribute to moist sites Findley, et al., Nature, 2013.

8 Gender based skin microbiota differences Sex based differences exist in skin microbiota Female microbiota are more diverse, when accounting for hand washing Other factors may be more significant Ying, et al., PLoS One, 2015 Fierer, et al., PNAS, 2008

9 Factors that drive microbiota gender based differences Physiological Environmental Handedness Hygiene Cosmetics Environment Ethnicity Others

10 Evolutionary history may also contribute Different populations harbour unique microbiota Mirrors what is observed in other body sites Could play a role in sex based differences, i.e. Treponema sp. in Hadza female gut microbiota from tuber collection G. Perez, et al., PLoS One, 2016.

11 Technical Limitations with 16S rrna studies Skin swabs are typically low biomass samples DNA recovery yields need to be maximised Contaminant taxa need to be assessed Extraction blank controls (EBCs) No template controls (NTCs) Weyrich, et al., Submitted.

12 Environmental exposure = increased diversity Prolonged environmental exposure increased overall diversity Increased exposure increased total obtained taxa Baseline reset after showering Mills, et al., In preparation

13 Environmental microbiota transfer to the skin Staphylococcus sp. decreased Other taxa were obtained from the environment Dynamic interplay between taxa Mills, et al., In preparation

14 Rewilding hypothesis Reinstate lost microbial diversity through environmental biodiversity exposure Impacts on immune dysfunction and loss of competitor species Mechanisms and potential pitfalls need to be explored, especially in the context of different genders Mills, Weyrich, et al., Restoration Ecology, In press

15 Looking to the future Probiotic development Adverse effects must be tested in different age ranges: Lactobacillus acidophilus N. Elazab, et al., Pediatrics, 2013 Cosmetic based probiotics (Nerd skincare) Microbial transplants for the skin? Immune therapy through prebiotics? A fecal transplate equivalent for the skin? Specific microbial correlates of skin disease Statnikov, et al., Scientific Reports, 2013

16 A U S T R A L I A N C E N T R E F O R A N C I E N T D N A l a u r a. w e y r i c a d e l a i d e. e d u. a A C A D A d e l a i d l s w e y r i c h