This One Ingredient We All Consume May Be Harming Our Gut Health

Tiny plastic particles have worked their way into the everyday food supply. Researchers have measured them in drinking water, seafood, table salt, honey, and the packaging that holds a large share of what we eat. They've also been found in the bloodstream, liver tissue, and even gallstones.

So the question is, what happens when these particles linger? Because food is the main way plastic particles get into the body, the gut is the first place they land and the tissue they spend the most time in contact with. A new review published in the journal Current Developments in Nutrition1 recently distilled the current on how microplastic accumulation in the gut may impact overall health. Here's what you need to know.

How microplastics may impact the gut

The review brings together research from animal models, laboratory simulations of the human gut microbiome, and observational studies in humans to propose what's called the “microplastic–gut microbiota–nutrition axis.”

Researchers examined more than 75 studies published between 2020 and 2025 to explore how microplastic exposure may interact with gut bacteria—and, in turn, influence nutrition and metabolism. They highlighted four potential pathways that microplastics may interfere with gut health.

Gut bacteria that live in your large intestine produce compounds (like short-chain fatty acids or SCFAs) that positively influence how your body processes food. SCFA in particular are known for their role in protecting the gut barrier, supporting immune health, and helping your metabolism run smoothly.

According to the review, microplastic exposure may disrupt the bacteria responsible for producing these compounds and alter bile acid metabolism. In theory, those changes could influence how the body extracts and processes energy from food. Although much of this research comes from lab or animal studies rather than human.

A healthy intestinal barrier helps keep potentially harmful substances inside the digestive tract while allowing nutrients to pass into circulation.

Some studies included in the review suggest that microplastic exposure may contribute to changes in intestinal permeability and inflammation. If the gut barrier becomes more permeable, bacterial components such as lipopolysaccharide may enter the bloodstream. This process (sometimes referred to as metabolic endotoxemia) has been associated with inflammation and metabolic dysfunction.

Researchers have not established that typical dietary microplastic exposure causes metabolic endotoxemia in humans.

The researchers also propose that microplastic-induced changes in the gut environment could interfere with the availability or absorption of certain nutrients. The review draws largely on mechanistic and preclinical research, so we can't yet say that microplastics cause vitamin or mineral deficiencies in people.

Still, the possibility is worth investigating, especially because the gut microbiome plays a role in the metabolism and absorption of several nutrients.

Your gut and brain are in constant communication through what's known as the gut-brain axis. Gut microbes produce metabolites and interact with hormonal, immune, and neural pathways that can influence appetite and energy balance. The review suggests that if microplastics disrupt the gut microbiome, they could potentially influence these signals.

But there currently isn't good evidence showing that microplastic exposure directly makes people hungrier or causes overeating.

What about your diet?

The researchers suggest that a Western-style dietary pattern, which is typically higher in ultra-processed foods and lower in fiber, could make the gut more vulnerable to microbiome disruption. A low-fiber diet, for example, provides fewer of the substrates gut bacteria need to produce beneficial SCFAs.

That raises the possibility that diet quality could influence how the gut responds to environmental exposures like microplastics. And as fiber is crucial for supporting the elimination of toxins in the GI tract, eating more fiber may help provide a layer of protection.

But this is still a hypothesis, not a reason to believe that a particular diet can truly rid your body of microplastics. Sigh.

So, should you be worried about microplastics?

Microplastics are absolutely something you want to minimize exposure to, although that is easier said than day in this day and age. And while this review makes a compelling case for studying the connection between microplastics, the gut microbiome, and nutrition, it does not prove that everyday exposure is causing nutrient deficiencies, weight gain, or metabolic disease.

Many laboratory and animal studies use levels of microplastic exposure that may not reflect the amounts humans encounter through food and water. Microplastics also aren't one uniform substance: Their size, shape, polymer type, and chemical additives can all influence how they behave in the body.

The takeaway

The science linking plastic particles to gut and metabolic health is still early. Researchers have mapped out very plausible ways these particles could disturb gut bacteria, but nearly all of it comes from animal and lab work using exposure levels far beyond what people encounter.

In the meantime, the basics of gut health haven't changed: Prioritize a diverse, fiber-rich diet, plenty of plant foods, and overall dietary quality.