Abstract

Obesity-induced insulin resistance emerges from intertwined host–microbe interactions that reshape intestinal 
permeability, immune tone, and metabolic signaling. Dysbiosis, characterized by reduced microbial diversity, 
altered short-chain fatty acid production, perturbed bile acid pools, and increased endotoxin translocation, 
amplifies systemic inflammation and impairs insulin action. Conventional approaches—dietary fiber, probiotics, 
and antibiotics often show variable efficacy due to poor colon targeting, instability across the gastrointestinal 
tract, off-target effects, and person-to-person microbiome heterogeneity. Engineered nanoparticles offer a 
precision toolkit to tune the gut ecosystem and its crosstalk with the host. By co-optimizing materials, size, 
surface chemistry, and stimuli-responsive release, nanoparticles can protect labile cargos, navigate mucus and 
epithelial barriers, selectively deliver prebiotics, postbiotics, enzymes, microbial modulators, or gene editors to 
specific niches, and even sequester luminal toxins such as lipopolysaccharide. This review articulates design 
principles for gut-directed nanocarriers; examines strategies to enrich beneficial taxa and functions, attenuate 
pathobionts, and restore barrier integrity; and outlines theranostic systems that couple localized imaging with 
microbiota-targeted therapy. We evaluate safety, manufacturability, and regulatory considerations, and propose 
clinical trial frameworks integrating multi-omics, breath and plasma metabolomics, and continuous glucose 
monitoring. By aligning materials science with microbial ecology, nanoparticle platforms can convert 
microbiome modulation from broad-stroke interventions into targeted, durable, and metabolically meaningful 
therapy.