Can you take something that binds plastic in your gut?

If you have followed the microplastics story for any length of time, there is one question you eventually arrive at: Is there anything I can take that helps?

That question has led researchers down two very different roads — one built around living probiotic bacteria that stick to plastic particles as they pass through the gut, and one built around non-living fibers that act like a sponge. Both aim at the same target. Their evidence bases look different.

The probiotic approach: living binders

The larger and more mechanistically detailed body of evidence sits on the probiotic side.

The idea is straightforward. Certain bacteria — mostly Lactobacillus and Bifidobacterium species — have cell surfaces covered in sticky lipoproteins and sugar chains. When microplastic and nanoplastic particles move through the gut, the bacterial surface acts like Velcro for them: the particles physically stick, then leave the body clumped with the bacteria in normal digestion. Because probiotics are alive, they also do the ordinary things probiotics do — support the gut lining, calm inflammatory signaling, help maintain microbial balance ^[1].

The evidence has built up quickly.

• In laboratory tests, the best-performing strains bound roughly two-thirds to three-quarters of the plastic particles in the water around them ^[1].
• A team that screened 88 native probiotic candidates found a three-strain mix that removed up to 77% of nanoplastics in a gut model ^[2].
• A larger 2025 screen of 784 bacterial strains identified one that boosted stool excretion of microplastics in mice by roughly 1.5-fold, alongside reduced intestinal inflammation ^[3].
• A 2026 study in Scientific Reports showed that specific yogurt strains suppressed nanoplastic penetration through intestinal cells — evidence the effect isn't limited to lab beads and reaches the barrier itself ^[4].

Earlier this year, the entire probiotic-and-microplastic literature was pulled together in a peer-reviewed systematic review in Probiotics and Antimicrobial Proteins (Adabi et al., May 2026) ^[5]. Fifteen studies (three in vitro, twelve in vivo) each supported the mechanism. And the review states plainly what the field also has to say plainly: no human clinical trial has yet tested a probiotic for microplastic clearance in people.

That is exactly what “science-backed, not yet clinically proven” is supposed to sound like. We’ve walked through the underlying strain-by-strain evidence in more depth in our companion piece Can probiotics bind microplastics?.

The non-living binder approach: chitosan and other fibers

The other road being explored uses non-living materials — usually chitosan, a natural fiber derived from crustacean shells. Chitosan works the way a very fine sponge does: it swells in the gut, binds particles by electrostatic attraction, and gets carried out in stool. It is inert and single-purpose.

Chitosan does have a head start in one specific place: it now has two small human pilot studies.

• A 2025 pilot in Foods gave healthy adults a single dose of chitosan before a meal; stool microplastic excretion went up by roughly half compared with placebo ^[6].
• A 2025 Scientific Reports pilot in Japan reported a similar direction of effect after several days of oral chitosan ^[7].
• In early 2026, a small Italian trial (n=11 chitosan, n=10 placebo, 15 days) reported an average drop of about a quarter in blood microplastic levels in the chitosan group ^[8].

That’s a real signal, and it deserves credit as the first-mover human data in this space. It is also a very early signal — small samples, short trials, single labs, and measured against real methodological headwinds we describe below. None of it establishes that binding a particle in the gut reduces long-term tissue burden, let alone changes any health outcome. That work has not been done for chitosan any more than for probiotics.

Two mechanisms, one gut

Both approaches aim at the same choke point: intercept plastic particles inside the gut, before they cross into circulation. What they bring to that job is a little different.

Chitosan is a targeted binder. It grabs particles by physical and electrostatic forces and moves them out. Simple, well-defined, single-purpose — one job, done well.

Probiotics do that job and another one. The living cell surface binds particles the same way a fiber does — but because the cells are alive, they also support gut-barrier integrity, produce short-chain fatty acids, and help maintain microbial diversity. Two jobs from one daily dose, plus benefits that stand on their own regardless of the microplastic story.

So if you had to pick one, the case for a probiotic is pretty clean: same particle-binding job, plus a second one you already care about.

Why “why not both?” is the more interesting question

The two mechanisms are not in competition — they work in different ways on the same problem, and there is no obvious reason they would interfere. A binder catches particles by physical entrapment. A probiotic strain catches particles by cell-surface adhesion and strengthens the environment those particles are moving through. Layered, they should complement rather than cancel.

No study has yet paired them in humans. It is an obvious next question for the field, and one worth watching. The polyphenol trial we just described ^[9] proves the trial design is now available; layered-intervention trials will follow.

The trial that opens the door

A useful new landmark for both camps arrived in April 2026: a genuine randomized, double-blind, placebo-controlled human trial published in Nature Communications used composite polyphenols (not probiotics, not chitosan) to test whether a dietary intervention could measurably reduce fecal microplastic burden and downstream inflammatory markers ^[9]. Ninety-eight participants, 28 days. It worked well enough to publish in a top journal.

The important point isn’t the polyphenol result. It’s that the trial design now exists — an RCT that uses fecal microplastic quantification as a real endpoint. Any credible next step for probiotic binding needs to follow that template.

Notes on the science

Measuring microplastics inside the human body at these very low levels is still hard. The main lab technique used to measure plastic in blood and tissue can confuse breakdown products of body fats for polyethylene, which may inflate some published numbers ^[10]. A 2025 comparison across 84 labs handed identical samples found variability between them of 45 to 129% ^[11]. Even routine nitrile lab gloves shed particles that can look like plastic under analysis if a lab isn't specifically controlling for it ^[12].

None of this means the human pilots are wrong. It means the specific numbers should be treated as directional signals until independent labs replicate them.

Where Winnow fits in

Winnow started on the probiotic side of this map for the reason above: if a daily intervention is going to earn a place in your routine, it should ideally do more than one thing. Our patent-pending strains were selected in laboratory testing to bind micro- and nanoplastic particles within the gut lumen, before absorption, while doing the ordinary things a good daily probiotic does — supporting gut-barrier function and helping maintain a balanced microbiome ^[1,3].

Those are preclinical results, and we say so plainly. A human trial is the field’s next serious question, and we intend to be part of the answer. We are also watching the binder literature closely — the mechanisms are complementary, and the most defensible long-term response to this exposure problem may well involve stacking them. Every group taking this seriously is contributing to the same shared goal.