Dust microbiome

People spend a significant amount of time indoors, especially within their homes, where they are exposed to a large number of microbes which can have important implications for their health. With the advancement of sequencing technologies, it is now possible to study the indoor microbiome and how it affects the inhabitants. House dust is the main reservoir of microbial taxa in the domestic environment. The amount and diversity of the microbiome in dust affect health, especially because dust-born microbes and their products suspend into the air and produce a significant indoor exposure by breathing.

Indoor dust includes different fungi and bacteria (mostly gram-positive bacteria). Molecular methods such as next generation sequencing are reliable tools for identifying and tracking the bacterial and fungal diversity in dust samples. For that purpose, 16S ribosomal RNA gene (16S rRNA gene) (V3-V4 region) and internal transcribed spacer (ITS) amplicon (ITS2 region) are commonly analyzed.

Many studies on the microbiome of house dust have focused on microbial taxa associated with allergies and asthma. Interestingly, higher microbial diversity in the environment has been found to be inversely associated with asthma. For example, children who grow up in the environments with a wide range of microbial exposures, like farming environments or households with a lot of members, are more likely to be protected from childhood asthma and atopy than urban children and single children.

Most prominent environmental factors affecting the house dust microbiome are:

living conditions – moisture is associated with more fungi and molds
level of urbanization - more urbanized areas have a lower microbial diversity and higher allergy rates
season – significant variation in fungal, but not bacterial composition
pets – contribute to higher microbial diversity, which reduces health risks

References:

Gangneux JP, Sassi M, Lemire P, Le Cann P. Metagenomic Characterization of Indoor Dust Bacterial and Fungal Microbiota in Homes of Asthma and Non-asthma Patients Using Next Generation Sequencing. Front Microbiol. 2020 Jul 30;11:1671. doi: 10.3389/fmicb.2020.01671.

Gupta S, Hjelmsø MH, Lehtimäki J, Li X, Mortensen MS, Russel J, Trivedi U, Rasmussen MA, Stokholm J, Bisgaard H, Sørensen SJ. Environmental shaping of the bacterial and fungal community in infant bed dust and correlations with the airway microbiota. Microbiome. 2020 Aug 7;8(1):115. doi: 10.1186/s40168-020-00895-w.

Shan Y, Wu W, Fan W, Haahtela T, Zhang G. House dust microbiome and human health risks. Int Microbiol. 2019 Sep;22(3):297-304. doi: 10.1007/s10123-019-00057-5.