Fermented garlic as a functional food strategy for malnutrition: microbial ecology, bioactive compounds, and clinical...

Fermented garlic (Allium sativum) represents a promising functional food with potential applications as a complementary nutritional intervention for malnourished populations. Through microbial fermentation and thermal processing two mechanistically distinct pathways, garlic undergoes significant biochemical transformations that enhance the availability of bioactive compounds, including S-allyl-L-cysteine (SAC), polyphenols, and γ-aminobutyric acid (GABA), which collectively contribute to improved antioxidant capacity and gut health. This comprehensive review examines the microbial ecology underlying garlic fermentation, the biochemical pathways that generate bioactive metabolites, and the mechanistic basis by which fermented garlic employed in the broader food fortification strategy or incorporated into fortified therapeutic food formulations targeting clinical malnutrition, may support nutritional recovery in the context of Environmental Enteric Dysfunction (EED), the dominant gut pathology underlying stunting and wasting in low- and middle-income countries (LMICs). Fermented garlic is a bioactive-dense nutritional adjuvant rather than a macronutrient source, its clinical relevance lies in potential enhancement of gut barrier integrity, reduction of mucosal inflammation, and support of micronutrient bioavailability, rather than direct caloric contribution. Preclinical evidence from animal models demonstrates improvements in intestinal morphology, metabolic parameters, and immune function, suggesting potential utility in nutritionally stressed populations. However, well-designed human clinical trials specifically examining fermented garlic in malnourished populations are currently underrepresented in the literature, and all translational implications discussed herein remain preliminary. Substantial research gaps persist regarding optimal dosage, long-term clinical safety, and standardization of fermentation protocols. This review identifies critical research priorities necessary to establish fermented garlic as a scalable, culturally acceptable food-based complementary intervention for vulnerable populations worldwide.