A research article on biodegradation of PAHs and microbiota changes in commonly used urban landscaping materials has been published in PeerJ. The article written by Marja Roslund et al. is based on the fact that polycyclic aromatic hydrocarbons (PAHs) accumulate in urban soils, and PAH contamination can change soil microbial community composition. Environmental microbiota is associated with human commensal microbiota, immune system and health. In the study, four landscaping materials were contaminated with PAHs commonly found at urban sites in PAH concentrations that reflect urban soils in Finland. The results indicated PAH degradation depended on the organic matter content and bacterial community composition of landscaping materials. Contamination seems to alter bacterial community composition in landscaping materials depending on material type. This alteration includes changes in bacterial phyla associated with human health and immune system. This may open new possibilities for managing urban environments by careful selection of landscaping materials, to benefit health and wellbeing.