Spore-Forming Probiotic Biomaterials Proposed for Targeted Gut Microplastic Biodegradation

Exposure to microplastics (MPs) in the gut is a growing concern, known to compromise gut barrier integrity, disrupt microbial homeostasis, and impair host immunity, ultimately accelerating mucosal dysfunction and disease progression. Current strategies for plastic biodegradation, effective in environmental settings, face significant limitations within the harsh physiological constraints of the gut. Spore-forming probiotic (SFP) strains offer a promising avenue due to their intrinsic resilience and diverse metabolic capacities for plastic degradation, but their functional deployment is hindered by spatial dilution, enzyme instability, and insufficient polymer-microbe contact.

This perspective article outlines a novel conceptual framework for addressing gut microplastic accumulation by leveraging spore-forming probiotics (SFPs). The authors discuss strategies for embedding SFPs into engineered biomaterial platforms, specifically focusing on microcapsules, hydrogels, and polymer films. This approach aims to overcome current limitations by localizing probiotic activity, regulating their germination and secretion dynamics, and mediating controlled interactions with microplastics directly within the challenging gut-physiological conditions.

The authors propose that SFP-integrated biomaterials can effectively circumvent the feasibility restrictions faced by conventional plastic biodegradation mechanisms within the gut. They detail the mechanistic basis of SFP-mediated microplastic degradation, which includes enzymatic, biosurfactant-mediated, and oxidative pathways. These pathways leverage the intrinsic resilience and diverse metabolic capabilities of SFPs. The proposed biomaterial design strategies are intended to ensure optimized targeted activity.

The core proposal is that embedding SFPs into engineered biomaterials will enable controlled microbe-microplastic interactions, optimizing targeted activity within the gut by localizing probiotic function and regulating their dynamics. This controlled environment is crucial for effective degradation, ensuring sufficient polymer-microbe contact and enzyme stability, which are often lacking in free probiotic applications.