Global agriculture faces unprecedented challenges, including a projected population of 10 billion by 2050, declining arable land, and the urgent need to phase out antibiotic growth promoters (AGPs) to stem antimicrobial resistance (AMR). This review evaluates fermentation technology as a sustainable solution to the “food–feed–fuel” three competing land uses. We systematically compare solid-state fermentation (SSF) and submerged fermentation (SmF), highlighting their quantitative advantages: SSF offers 2–3× higher volumetric productivity and 70–90% lower water usage for solid wastes (e.g., soybean meal, wheat bran), while SmF provides superior process control for high-value products (e.g., single-cell protein). Key molecular mechanisms are discussed, including enzymatic degradation of anti-nutritional factors (up to 95% phytate and 98.8% tannin removal), mycotoxin detoxification (60–80% reduction), and biosynthesis of bioactive compounds (e.g., vitamin B12 enrichment up to 15-fold). Fermented feeds benefit many livestock species, particularly in organic and high-density farming systems, improving growth performance, gut health, and disease resistance while reducing environmental footprints. Advanced technologies such as AI-driven digital twins, CRISPR-based strain engineering, and precision fermentation are explored to overcome bottlenecks, including heat dissipation, strain stability, and process control. Despite challenges in scale-up, economics, and divergent global regulations (EU, USA, China, Southeast Asia, and Africa), fermentation is a critical biotechnological paradigm for circularity—the circular bioeconomy—and long-term food security. Future research should prioritize cost-effective large-scale implementation and the harmonization of regulatory frameworks.
Zhang et al. (2026) studied this question.