A substantial body of research has established a link between immersion in natural environments and a broad spectrum of health advantages. These benefits range from enhancements in cognitive performance and reductions in blood pressure to improvements in psychological well-being. Furthermore, some investigations have identified correlations between the human microbiome and the amount of time individuals spend in outdoor settings. However, a frequently overlooked and inadequately explored element within this relationship is the community of microorganisms residing in the nasal passages, often referred to as the nasal microbiome.
In an effort to address this knowledge gap, scientists affiliated with the Denver Museum of Nature & Science undertook a recent investigation. This study, conducted within the museum premises and involving the participation of 111 museum visitors as part of the research cohort, enabled microbiologists to pinpoint specific nasal microbial signatures and patterns that were associated with the participants’ psychological state and their degree of exposure to parks and other verdant areas.
Dr. Bridget Chalifour, a genomics scientist and a lead investigator at the museum, spearheaded this research initiative. She presented the findings derived from the analysis at the ASM Microbe 2026 conference, which convened in Washington, D.C.
The museum features an on-site genomics laboratory, which serves as Dr. Chalifour’s workspace and is visible to visitors through transparent walls. According to her, participants in this study were invited to furnish nasal swabs and complete standardized questionnaires designed to assess their mental well-being, the duration of their outdoor activities, and their history of pet ownership. The process of obtaining swab samples was remarkably straightforward. Dr. Chalifour remarked, “Following the COVID-19 pandemic, individuals have become quite adept at collecting their own nasal samples.”
In conjunction with her colleagues, Dr. Chalifour employed 16S rRNA sequencing techniques to meticulously document the nasal microbiomes of the participating individuals. They also engaged the museum’s team of earth science researchers to ascertain the proximity of green spaces for the participants, based on their residential addresses, by utilizing publicly accessible satellite imagery data.
The initial analytical results suggest that both exposure to green spaces and the presence of pets exert a considerable influence on the composition of the nasal microbiome. These findings align with previous research that has explored the connections between microbes and mental health. The study revealed that individuals residing in areas with more abundant vegetation tended to exhibit a greater diversity of microbial life within their nasal passages. Certain microorganisms were observed to be either more or less prevalent depending on the extent of the green spaces in their immediate vicinity.
We tend to associate greater diversity and greater richness with a healthier microbiome.”
Bridget Chalifour, Ph.D., principal investigator at the museum
A portion of the microbial species that showed a correlation with extended periods spent outdoors also demonstrated an association with enhanced mental health metrics.
The analysis further indicated that the duration of time spent in outdoor environments had a more pronounced impact on the health of the nasal microbiome than direct exposure to green spaces. Dr. Chalifour emphasized the significant role of time, stating, “Time proved to be critically important across all facets. Individuals who dedicated more time to outdoor activities, irrespective of the greenness of their surroundings, generally reported lower levels of depressive symptoms.”
Delving into further detail, she noted that the nasal microbiome appears to adapt in response to these lifestyle choices, potentially playing a role in facilitating positive shifts in mental well-being. Dr. Chalifour observed, “Simply by increasing their time spent in natural settings, individuals are actively modifying their microbiomes.”
According to Dr. Chalifour, this study marks one of the initial forays by the museum’s team into the field of microbiology. However, she highlighted that the institution has a long-standing and well-established tradition of conducting rigorous scientific research across a multitude of disciplines. She affirmed, “We conduct a considerable amount of genuine scientific research at the museum.”
