Exploring the Probiotic Potentials of Three (3) Selected Nigeria Spices Essential Oils on Human Gut Microbiota

The probiotic potentials of three (3) (Clove (Syzygium aromaticum), Garlic (Allium sativum), and Turmeric (Curcuma longa) selected Nigeria spices essential oils on human gut microbiota was explored. The human gut microbiome is a complex and dynamic community of microorganisms that can be influenced by EOs. Comprehensive research directly comparing the probiotic potentials of Cloves, Garlic and Turmeric EOs on human gut microbiota are scanty hence this study. Essential oils were extracted through steam and hydro-distillation, with yields ranging from 1.5–1.6% (highest in Garlic oil). GC–MS analysis revealed major bioactive compounds—Eugenol in Clove, Zingiberene and diallyl disulfide/trisulfide in Garlic and α/β-Turmerone in Turmeric—indicating rich phytochemical diversity and strong bioactivity potential. Microbiological analyses of fecal samples identified diverse gut bacteria, including beneficial (Lactobacillus, Bifidobacterium, Akkermansia) and pathogenic (E. coli, Salmonella, Staphylococcus) species. When treated with graded EO concentrations (0.1–1.0%), beneficial bacteria maintained high viability (93–99%), while pathogenic strains showed significant inhibition (40–74%), particularly under Garlic and Clove oil treatments. Turmeric essential oil (TEO) exhibited mild antibacterial activity against pathogens and preservation/enhancement of probiotics. Reduction in cell viability were: E. coli (49.02%), Salmonella (39.50%), Proteus (28.56%). Staphylococcus (16.19%), and Citrobacter (12.34%). Others are Lactobacillus (0.73%), Bifidobacterium (2.48%) showed minimal reduction. Akkermansia viability was high (96.03%). Statistical analyses (ANOVA, p ≤ 0.05) confirmed significant effects across treatments. Overall, the study demonstrates that essential oils from Nigeria spices possess strong probiotic potentials, capable of enhancing beneficial gut flora, suppressing pathogens. The findings have established a scientific baseline for utilizing local botanicals as natural nutraceuticals to promote gut health.