Postbiotic Bound Up to 92 Percent of Nanoplastics in Lab Tests but Human Gut Protection Not Shown

A postbiotic developed by Quorum Innovations bound up to 92 percent of nanoplastics in fluids mimicking parts of the digestive system, according to tests described in a preprint posted on bioRxiv. The product, called Qi601, consists of cell walls from heat-killed Limosilactobacillus fermentum bacteria.

When researchers incubated microplastics with Qi601, the particles adhered to the rough surfaces of the bacterial cell walls.

In separate tests with human intestinal-like cells, nanoplastics accumulated inside and on the cells without the postbiotic. Adding Qi601 after 24 hours of prior exposure reduced the number of particles inside the cells by 43 percent. In a human trial component, participants chewed commercial gum to release microplastics into saliva.

Analysis of one participant's saliva showed 2,152 freely floating plastic particles after chewing gum alone. Placing 10 milligrams of powdered Qi601 in the mouth after five seconds of chewing lowered the count to 185 particles. Microplastics are defined as plastic particles less than 5 millimeters long and have been detected throughout the human body.

People with arterial plaques containing microplastics face more than four times the risk of heart attack or stroke compared with those whose plaques contain no plastic, while higher concentrations have been reported in the brains of people with Alzheimer’s disease.

Eva Berkes, co-founder and chief scientific officer at Quorum Innovations, said the results represent the first demonstration of microplastics being bound by a microplastic mitigant in people. The study has not shown that the particles were prevented from entering cells in the human gut or that they were excreted.