Humans differ in their personal microbial cloud

Abstract

Dispersal of microbes between humans and the built environment can occur through direct contact with surfaces or through airborne release; the latter mechanism remains poorly understood. Humans emit upwards of 106 biological particles per hour, and have long been known to transmit pathogens to other individuals and to indoor surfaces. However it has not previously been demonstrated that humans emit a detectible microbial cloud into surrounding indoor air, nor whether such clouds are sufficiently differentiated to allow the identification of individual occupants. We used high-throughput sequencing of 16S rRNA genes to characterize the airborne bacterial contribution of a single person sitting in a sanitized custom experimental climate chamber. We compared that to air sampled in an adjacent, identical, unoccupied chamber, as well as to supply and exhaust air sources. Additionally, we assessed microbial communities in settled particles surrounding each occupant, to investigate the potential long-term fate of airborne microbial emissions. Most occupants could be clearly detected by their airborne bacterial emissions, as well as their contribution to settled particles, within 1.5–4 h. Bacterial clouds from the occupants were statistically distinct, allowing the identification of some individual occupants. Our results confirm that an occupied space is microbially distinct from an unoccupied one, and demonstrate for the first time that individuals release their own personalized microbial cloud.

Geography and location are the primary drivers of office microbiome composition

“…The source of the cityspecific BE microbial communities that we observe will be important to understand better, as it could for example result in cityspecific "cage effects" in murine microbiome studies. We observe that around 25 to 30% of the office surface microbiomes are humanderived (Figure 7), primarily from human skin, suggesting that indirect contact does impact office microbiomes (e.g., through the the office inhabitants' "personal microbial clouds" (25) ), but this is far less than what would be expected on surfaces that the inhabitants are in direct contact with (14,20) .…”

Emission rates and the personal cloud effect associated with particle release from the perihuman environment

“…Some studies refer to the personal cloud as the particulate matter contribution from human skin and clothing to the room air (otherwise referred to as "human particle emissions"). 13,16 Other studies define the personal cloud as a ratio of measurements between a personal and a stationary monitor. 7 The ratio of personal to room average particle levels is not expected to be a stable indicator of the personal cloud effect, as that ratio would be sensitive to exogenous factors that could vary strongly from one condition to another.…”

“…15,19,44,45 Increasing evidence identifies human occupancy as an important source of airborne bacterial and fungal DNA in indoor air. 11,12,16 Particles detached from the human envelope might also carry chemical and other potentially harmful agents, such as residual detergents and post-manufacturing hazardous substances that remain in clothing and textiles, and that are otherwise known to cause allergic sensitization and other health effects.…”

Gut Microbiota Dysfunction as Reliable Non-invasive Early Diagnostic Biomarkers in the Pathophysiology of Parkinson's Disease: A Critical Review

“…6,[42][43][44][45][46] Although the microbiome is inherited from the mother, eventually the microbiome changes to one's own unique signature. 39,47,48 The gut microbiota changes constantly according to our food habits and the environment. 49 Recent reports claim that the origin of PD does not take place in the substantia nigra alone and its pathology involves extranigral regions as well.…”