HUMAN MICROBIOME AT YOUR FINGERTIPS: STATE-OF-THE-ART AND FORENSIC OPPORTUNITIES

The human skin, as the largest organ, hosts a wide range of rich and diverse microbial communities. These are a mixture of resident (or core) and transient species that are dependent on multiple variables including person-specific, and environmental. Together they contribute to an individual’s unique microbial profile. The skin microbiome composition also varies across different body sites. Although the role of microbes within the human body is being progressively elucidated, particularly within the context of health and medicine, their exploitation within forensic science is still being researched. By mining the published literature between 2010 and 2026, this mini-review maps the application of "omics" techniques detecting microbial populations on skin and fingermarks, with the purpose of understanding the limitations, opportunities and what further forensic research should encompass to exploit the untapped potential of detecting, identifying and visualising the fingermark microbiome, in support to criminal investigations. Identified key gaps in knowledge derive, amongst others, from technical limitations and interpretative uncertainty with respect to genomic techniques, different severity of the challenges in disrupting the cell walls across bacterial populations when using molecular techniques such as mass spectrometry, and challenges in maintaining a contamination-free environment. These issues are compounding factors when considering the evolving nature of the microbiome and the present impossibility to directly correlate the skin and/or fingertip microbiomes to the fingermark microbiomes. This mini-review therefore also provides suggestions to overcome these challenges and mitigate/fill these gaps in knowledge.