22nd March 2022 – By Aaruthy Suthahar

The bacteria in your gut is linked to the environment around you, according to latest research from TwinsUK.  

Exposure to natural environments, also known as greenspace, has been shown to have a positive influence on our health, but the mechanisms as to why are still not clear. We know from previous research that gut bacteria is linked with inflammatory illnesses; inflammatory illnesses are also more prevalent in urban areas and in individuals who have lower levels of exposure to greenspace. Therefore, gut bacteria could act as one of the links between greenspace and health.  

The team studied 2,443 participants from the TwinsUK cohort to see if there was a difference in gut bacteria in individuals living in rural and urban environments. The researchers looked at the amount of greenspace at three different distances from a participant’s home: 800 m, 3000 m, and 5000 m. The aim was to understand if there was any evidence of bacteria differing with the amount of greenspace. 

The team found there were differences in bacteria between different greenspace areas and when comparing rural versus –urban microbes. One hypothesised reason could be that people are exposed to a range of microorganisms and therefore have a stronger immune system as they are exposed to a wider range of bacteria. Levels of bacteria associated with disease were higher in individuals living in more urban environments compared to rural environments. 

A limitation of the study was the broad interpretation of “greenspace” as being any area in a non-urban environment. This meant that factors like the accessibility of land or the type and quality of habitats that were present could not be considered. Further work could design experiments to understand this further by comparing urban areas with high, accessible greenspace with urban areas of low, accessible greenspace. 

The different microrganisms residing along the human digestive tract, along with the things these microbes produce is collectively called the human gut microbiome. It has a crucial role as it interacts with the immune system, is vital for processing nutrients and protects individuals against pathogens.  

First author Ruth Bowyer said: 

“The results show that there are geographical patterns in the composition of the microbiota which does not appear to be explained by diet, BMI (Body Mass Index), and health deficit. Therefore, the results bring to light the potential importance of considering non-lifestyle factors that could affect microbiota composition.”