Modulation of the indoor aerobiome induced by a plant-based treatment device

<h2>Abstract</h2> Indoor air quality is a critical yet challenging factor for human health, given both the duration and heterogeneity of exposure. The development of collective protective systems capable of mitigating exposure to chemical pollutants and hazardous microorganisms is therefore essential. While green health strategies appear promising for enhancing biodiversity resilience, a strong evidence-based approach is required to validate their effectiveness. This study aims to evaluate the impact of an active plant-based air treatment device on the indoor aerobiome. Air sampling was conducted in two educational environments: a primary school and a university meeting room. Air quality was assessed using both culture-dependent and culture-independent (next-generation sequencing, NGS) methods. The global microbial contamination index ranged from 504 to 1747 CFU/m³. The applied aerobiome assessment protocol demonstrated reliable performance. Alpha diversity analysis indicated a significantly higher Shannon index values in outdoor (median 4.57) and treated indoor air (median 5.16) compared to untreated air (median 3.29) (pairwise ranking, p = 0.041). Beta diversity clustering was also observed, despite the limited sample size. Notably, the portable botanical biofilter significantly modulated the abundance of several microbial species, including some with potential implications for human health. This study is among the first to evaluate indoor aerobiome quality in relation to an active plant-based air treatment device. While promising effects on aerobiome modulation were observed, further research is needed to assess their repeatability, long-term consistency, and impact on human health.