We at Gastroenterology & Endoscopy News are thrilled to announce that we have revived our podcast, The Scope, which we hope will be a place for lively discussion of important topics in gastroenterology. In a recent two-episode series, Elena Ivanina, DO, MPH, a gastroenterologist and founder of the Center for Integrative Gut Health and Gut Love, in New York City, and David Johnson, MD, the chief of gastroenterology at Eastern Virginia Medical School, Old Dominion University in Norfolk, joined The Scope to discuss the increasingly important topic of microplastics.
Dr. Johnson and his colleagues recently wrote a paper on microplastic exposure, detailing the implications for GI health and diseases (Am J Gastroenterol 2025 Mar 12. doi:10.14309/ajg.0000000000003417). While far more research is needed to understand the effects of microplastics, early data suggest they are associated with a wide range of negative health effects. Below is an excerpt from their discussion.
Dr. Ivanina: Where are microplastics and nanoplastics found?
Dr. Johnson: These degradation products creep into everything, the water table, the soil, the water, the ice, the terrestrial life, and become pervasive in virtually every aspect of what we see, what we breathe, what we eat, and there’s virtually nothing in the environment that doesn’t have some evidence of the degradation of these products.
Dr. Ivanina: I read your paper in the American Journal of Gastroenterology, and what really struck me was that you cited that Americans ingest approximately 5 grams of plastic per week. That’s, like, a credit card! Has this always been the case or is this a new problem with new implications for our health?
Dr. Johnson: I think that’s an important point—the exponential increase in production of plastics and the reliance on plastics because they’re cheaper, they’re transportable, they’re universally easy. As this increases, the degradation and the tonnage of waste emissions of microplastics increase. And it’s estimated that the number is going to double from 2025 to 2040. And this is independent of wind, water, what we eat. The numbers are increasing dramatically over time.
Dr. Ivanina: Yeah, that is a little scary. What exactly should we be concerned about with the impact of microplastics on gut health and the microbiome?
Dr. Johnson: Well, the impact is considerable because the microbiome changes from microplastics are profound, and it may not change necessarily the bacterial diversity, but the studies have shown fairly consistently that it changes different phylum. As we look at different phyla and the implications of GI diseases in areas that you and I deal with, such as colon cancer, and we look at things like Actinomyces odontolyticus or Fusobacterium nucleatum, we’re finding that those two phyla [are associated with] colon cancer.
We’re finding the same thing for inflammatory bowel disease and liver disease. The gut biome is [involved in] the majority of the immune processes in the body; 80% of our immune system is gut driven. And we see these inflammatory responses as they relate to adverse effects, oxidative stress, inflammation, immune dysfunction, changes in biochemical or energy metabolism, cell proliferation in abnormal development of pathways, and even carcinogenicity.
Dr. Ivanina: To bring it to more of a practical level for gastroenterologists, how would you recommend that our colleagues evaluate patients for microplastic exposure and counsel them about prevention, limiting exposure and mitigation strategies?
Dr. Johnson: Well, we really can’t evaluate for exposure. There are no clinical tests right now outside of scientific research for exposure risks.
But as far as evaluating patients, I just come back to what makes common sense. When I talk to my inflammatory bowel patients, my liver patients, my post-cancer diagnosis patients, I say let’s look at your diet and let’s look at your patterns of demographic exposure, smoking, obesity, sleep, oral hygiene. Plastics now become part of that discussion.
There are a couple things that that I recommend. First, look at ways that you might practically decrease your microplastic intake. I hate giving diets or restrictions to patients because they can develop restrictive food disorders and we create more problems. I say use common sense.
Switch from bottled water. I used to keep a couple of bottles of water in my car because I’d be driving and I’d say, gosh, I’m thirsty. That’s the worst thing you can do because heat exposure to plastics incrementally accelerates the degradation of these polymers. Reduction of plastic intake from bottled water to tap water in one study reduced the microplastic intake, the number of particles within human tissues, from 90,000 to 4,000.
Food storage also is huge. Avoid heating food in plastics. It’s staggering. If you start to look at plastics and using them in a microwave, the effect of a microwave increased the evidence of microplastics by over 4.2 million, and the nanoplastics, 2 billion, just in three minutes in the microwave.
So, again, it comes down to common sense. Then, I think we can start to have reasonable and not explicitly avoidant conversations with our patients.
Dr. Ivanina: That is great advice. Sometimes we see plastic containers that say microwave safe, and I think it’s misleading. It’s just because they’re not going to melt in the microwave. But that doesn’t prevent the microplastics from entering the food.
Dr. Johnson: The other part of that is freezing. There’s not nearly the same degradation, but freezing plastics is also important. Temperature extremes are really the key. Think about all the popsicles that we’ve consumed over the years.
Dr. Ivanina: Fascinating. What an eye-opening, conversation. What do you think the future brings?
Dr. Johnson: I think that we have so many signals and they’re all consistently pointing towards pathogenic pathways for microplastics and nanoplastics. The implication is virtually universal, as it relates to a number of diseases that have been highlighted.
These are just tips of the iceberg, and I hope my conversation with you today was not to give you answers, but as we start to put this together, just getting started to ask good questions.
This transcript has been edited for length and clarity.
This article is from the October 2025 print issue.