Microplastics and probiotics: Mechanisms of interaction and their consequences for health

Abstract

Microplastics (MPs), synthetic polymer particles less than 5 mm in size, are an emerging contaminant with implications for both human and ecosystem health. Being widespread in food and water sources, MPs can disrupt gastrointestinal integrity, alter the microbiota composition, and provoke oxidative and inflammatory responses. Probiotics, live microorganisms known for their gut health benefits, are now being explored for their ability to mitigate these effects. This review synthesizes evidence from in vitro and in vivo studies on how MPs impact probiotic viability, adhesion, and biofilm formation, and how certain strains may counter MP-induced toxicity by modulating oxidative stress, immune function, and the epithelial barrier integrity. Additionally, this manuscript discusses emerging applications in environmental microbiology, such as the potential use of native and engineered probiotics for microplastic bioremediation. Although the current data highlight promising avenues, key gaps remain in our understanding of strain-specific mechanisms, long-term efficacy, and real-world applicability. Addressing these will be essential to advance probiotic-based strategies in both human and environmental contexts.

Keywords: Microplastics; epithelial barrier integrity; gut microbiota; oxidative stress; probiotics.

Figure 1.. Origins, exposure routes, and biological effects of microplastics. Microplastics originate from various sources including microbeads, industrial pellets, textiles, and tire wear; they disseminate through environmental matrices such as water, soil, and air. Human exposure primarily occurs via ingestion, inhalation, and dermal contact. Once internalized, microplastics may induce a range of health effects such as gut dysbiosis, inflammation, oxidative stress, endocrine disruption, translocation to distant organs, and immune modulation. In parallel, microplastics alter the soil microbiota, disrupt the marine biodiversity, and act as vectors for environmental pathogens, thus raising concerns for both the ecosystem and human health.

Figure 2.. Bidirectional interactions between microplastics and microorganisms. MPs can disrupt microbial cell functions by inducing membrane alteration, increasing ROS production, and compromising cell integrity. In contrast, certain microorganisms, including probiotics, may exert modulatory effects on MPs through adsorption, antioxidant production, reduced biofilm formation, and attenuated inflammatory responses.