Chemicals are everywhere. Everything in our world is made of elements, so everything is some type of chemical, and nothing is really “chemical-free.” But of course, not all chemicals are natural, and there are lots of synthetic chemicals that can affect the human body. Researchers wanted to learn more about how a wide range of synthetic chemicals might impact the community of microbes in the human gut–the human microbiome. The gut microbiome is closely linked to various aspects of human health, so changes there can affect us significantly.
This work, which was reported in Nature Microbiology, analyzed over 1,000 chemicals in laboratory experiments, and identified 168 of them that can harm gut microbes that are considered healthy or beneficial. These chemicals can disrupt the growth of these important microbes. Many of these chemicals can be introduced into the body through food or water intake, or simple exposure to the environment. This work has shown that they could be affecting us through our gut microbes.
The study also indicated that some chemicals, such as pesticides, herbicides, and insecticides; as well as some chemicals found in plastics and flame retardants, can interfere with the growth of gut microbes. Some could also promote the development of antibiotic resistance in bacteria, which is already known to be a major problem.
Right now, safety testing that evaluates chemicals does not take their impact on the gut microbiome into account.
"Safety assessments of new chemicals for human use must ensure they are also safe for our gut bacteria, which could be exposed to the chemicals through our food and water,” suggested co-corresponding study author Dr. Stephan Kamrad of the University of Cambridge.
We also don’t known exactly how much of these chemicals that gut microbes could be exposed to, and more research will be needed to confirm these findings and understand how the human body could be impacted.
"Now we've started discovering these interactions in a laboratory setting it's important to start collecting more real-world chemical exposure data, to see if there are similar effects in our bodies,” noted senior study author Professor Kiran Patil of the University of Cambridge's MRC Toxicology Unit.
The researchers suggested that people can take some steps to reduce their exposure to some of these chemicals, such as by thoroughly washing fruit and vegetables before eating them.
