Plastic bottles suspended in waterShare on Pinterest
A new study looks for links between microplastics and IBD. CasarsaGuru/Getty Images
  • People are exposed to microplastics throughout their lives.
  • Scientists are still unsure about the health effects of this exposure.
  • In a recent small study, researchers found that people with inflammatory bowel disease (IBD) had more microplastic in their stool than people without IBD.

In a new small-scale study, researchers have found an association between inflammatory bowel disease (IBD) and greater amounts of microplastics in stool. The findings appear in the journal Environmental Science & Technology.

However, the study does not demonstrate that microplastics cause IBD. Corroborating the findings and then identifying an explanation for the link requires further research.

IBD is an umbrella term that encompasses a range of conditions characterized by inflammation in the gastrointestinal tract. The two most common types are Crohn’s disease and ulcerative colitis.

A person with IBD may have diarrhea, rectal bleeding, weight loss, pain in their abdomen, and tiredness.

Researchers are still unsure of the causes, but they believe that IBD develops when a person who is genetically susceptible to this type of illness is exposed to a particular trigger. Understanding how big a role environmental triggers play requires more research.

In the new study, the researchers wanted to see whether there was an association between microplastics and IBD. People are exposed to microplastics throughout their lives, although the effects on health are not yet clear.

Dr. Maria Neira, director of Public Health, Environment, and Social Determinants of Health at the World Health Organization (WHO), says that “We urgently need to know more about the health impact of microplastics because they are everywhere — including in our drinking water.”

“Based on the limited information we have, microplastics in drinking water don’t appear to pose a health risk at current levels. But we need to find out more. We also need to stop the rise in plastic pollution worldwide.”

Dr. Yan Zhang is the corresponding author of the present study. He works in the State Key Laboratory of Pollution Control and Resource Reuse at the School of Environment at Nanjing University, in China, and he previously found that in animal models, microplastics accumulate in the liver, kidney, and gut.

He also found that this accumulation was strongly dependent on the microplastics’ particle size.

The researcher explained to Medical News Today that “Compelling evidence shows that microplastics mainly accumulate in the gut of various species and cause intestinal inflammation and metabolic disruption. Human exposure to microplastics is inevitable.”

“To assess the health risk of microplastics, estimating the exposure levels and burdens of microplastics in humans is critical. However, to date, accurate data concerning the burdens of microplastics in humans are lacking. Furthermore, the actual health risk of microplastic exposure to humans has always been a common concern.”

Given that people are commonly exposed to microplastics through the gut, the team wanted to understand whether there was any relation between microplastics and IBD.

To do this, they looked at study participants’ fecal samples. The researchers recruited 52 people with IBD and 50 people without IBD who were otherwise healthy.

The participants filled in a questionnaire about the foods and drinks that they consume, their working and living conditions over the previous year, the status of their IBD, and their demographic characteristics.

The scientists then analyzed the fecal samples to determine the quantity and type of microplastics that were present.

They found that the participants with IBD had significantly more microplastic in their feces than the healthy group.

Further analysis showed that the severity of ulcerative colitis and Crohn’s disease correlated with the amounts of microplastics.

Additionally, the team noted that the people with more microplastic in their stool samples tended to drink more bottled water, eat more takeaway food, or have greater exposure to dust where they lived or worked.

“For the first time, this study reveals that there is a significant difference in the concentration of microplastics in feces from IBD patients and healthy people. Our study also indicates that the characteristics of fecal microplastics are useful to estimate the gut exposure of microplastics.”

– Dr. Yan Zhang

However, the researcher cautioned against concluding that microplastics cause IBD.

“It is difficult to say that microplastics contribute to causing IBD, because IBD is a very complex systemic disease, and its etiology is not clear. We prefer to believe that people with IBD are more likely to retain microplastics.”

Also, the study did have limitations — first and foremost, its small size. Scientists need to conduct much larger studies before they can draw more solid conclusions.

And as the study authors note, “The concentration of [microplastics] in feces detected in this study cannot directly equal the concentration of [microplastics] in the gastrointestinal tract or human body.”

In other words, although people with IBD might excrete more microplastic, this does not mean that they have more in their bodies.