What does the term microbiome mean?

  • A microbiome is the collection of all the microscopic organisms (e.g., bacteria, archaea, viruses, fungi, and protozoa) living in a particular habitat/area. These organisms live in a community or ecosystem, where they interact with each other and their environment. Each part of the human body has unique characteristics and therefore, the potential to harbor a unique microbiome. A wealth of research has been conducted on the microbiome and human health, focusing mainly on bacteria and archaea. Your skin, gut, mouth, and belly button, for example, have very different conditions that support the growth of different types of bacteria, and each individual’s microbiome is unique.
  • Microbiomes exist outside of the context of the human body as well. All animals, plants, soil, rocks, etc. are covered in their own unique blend of microorganisms. Furthermore, every space we occupy also develops its own microbiome, including our homes, schools, offices, and hospitals.

What is a healthy building? How do we define it?

  • For the purposes of this study, when we discuss a building’s health, we are referring to the impact the building has on the health of its occupants. Therefore, there are many factors that contribute to a building’s health. Some examples are the presence of certain chemical or biological pollutants in the air or building materials, type of ventilation, building humidity, type of lighting, water quality, age, location, and the functions the building is used for (e.g., a hospital houses occupants who are mostly ill and who come into and out of the building rather quickly, while a home houses occupants who may be well or sick and who tend to stay within the same building for a long duration.)
  • “Sick building syndrome” (sometimes referred to as tight building syndrome) is a term used to describe situations in which the people working or living within a building begin to experience health complaints and discomfort. These effects are usually related to the amount of time the person spends within the “sick building” and can be as mild as frequent headaches and fatigue or as severe as Legionnaire’s disease or asthma. Working in a “sick building” can have a dramatic effect on the productivity and wellbeing of the occupants, leading to high rates of absenteeism.
  • Research and advancements in sustainable and green building practices has led to the intentional design of buildings to reduce their impact on the environment, and achieving a green building certification (i.e. LEED or Green Globes) has become common. There is increasing interest in understanding how building design affects indoor air and water quality, including indoor microbial communities,and the impacts that building materials and design may have on occupant health.

How are microbiomes characterized, detected, and measured?

  • Traditionally, microbiologists have relied on “culture methods” to determine which microorganisms are present in a sample. This method relies on placing samples under various growth conditions (for example, changing the type of food source, temperature, humidity) and waiting to see which organisms grow. This method is not only slow, but it only works for a small set of microorganisms that grow well in laboratory conditions.
  • Advances in microbiology and DNA sequencing has given scientists new tools to identify which microorganisms are living in a particular area. The fast paced advancement of the technology has resulted in the cost of use to come down, allowing wider access to the technology.
  • It is now possible to isolate the DNA present in a sample and obtain its sequence. This sequence can be used to identify the microorganisms that are present in the sample by comparing it to a database containing a multitude of microorganism sequences. While every individual’s sequence varies, there are many components that are shared among all the individuals of a particular species (humans, dogs, bacteria, viruses, etc.) By comparing the sequence from an “unknown” microorganism (the sample) to a “known” organism (one whose sequence has been added to the database by other scientists), a researcher can determine what organisms are present in the area they are sampling.