One particular soil bacterium has heath benefits. An ancient bacterium that thrives in soil, called Mycobacterium vaccae, has shown to reduce asthma symptoms and reduce tuberculosis in people. It may also lower stress and fight inflammation. Soil shows that there are benefits in getting your hands dirty.

A 2016 study reveals that the mere act of touching or breathing in the non-pathogenic bacterium from gardening soil will make it part of your own microbiome – and is good for you.

Microbiome, or microbiota, are symbiotic and pathogenic micro-organisms that share our body space. They are the micro-organisms that don’t cause diseases – they act in harmony with the human body (which is the host). The symbiotic relationship between the human host and its microbiota helps to form the host’s immune system. The immune system prevents diseases by recognizing good bacteria from harmful bacteria (nurturing good bacteria and fighting bad bacteria). Hence Mycobacterium vaccae in soil helps strengthen the immune system.

A team of molecular psychosomatic and integrative physiology researchers from the University of Ulm in Germany and the University of Colorado Boulder in America conducted a study on the Mycobacterium vaccae. Their research is titled ‘Immunization with a heat-killed preparation of the environmental bacterium Mycobacterium vaccae promotes stress resiience in mice’ published in the Proceedings of the National Academy of Sciences.

The researchers noted that a lack of exposure of people to micro-organisms in urban societies was causing an epidemic of inflammatory diseases as well as psychiatric disorders.

In their study with mice the researchers showed that stress disrupts the relationship between the microbiota and the host, resulting in exaggerated inflammation. However, when the mice were treated with Mycobacterium vaccae (bacterium in gardening soil), the mice had no stress-related pathology. The mice had become resilient to stress. The researchers therefore suggest that people should return to the old advice of getting their hands dirty – in garden soil.

The Mycobacterium vaccae bacterium was often referred to as ‘the old friend’ because of its benefits to people. Hence the old friend is a good friend. Getting back to gardening is the best way to get a healthy dose of Mycobacterium vaccae.

http://www.pnas.org/content/113/22/E3130.abstract?tab=author-info

Photographs: all photographs are by Frey & Mosby