Lignan-enriched nutmeg extract changes gut microbiota associated with aging in C57BL/6 mice

As the aging population grows, increasing interest in promoting healthy aging through dietary interventions is growing. Gut microbiota play a key role in age-related physiological decline and longevity. We investigated whether lignan-enriched nutmeg extract (LNX) could modulate the gut microbiota of aged mice. C57BL/6 mice (27 months old) were orally administered LNX for 5 weeks and compared to young (3 months) and aged controls. LNX significantly reduced body weight without affecting food intake. 16S rRNA sequencing showed that age-related microbial shifts, including decreased Firmicutes and increased Bacteroidota , were partially reversed by LNX. While microbial diversity was unchanged, LNX increased Bifidobacterium , Blautia , and Acetatifactor muris , a taxon previously associated with healthy aging, and reduced Turicibacter sanguinis , linked to normal aging. These findings suggest that LNX modulates specific microbial taxa without broadly restoring a youthful microbiota composition. • Lignan-enriched nutmeg extract (LNX) reduces body weight in aged mice. • LNX does not restore reduced microbial diversity in aged mice. • LNX alters gut microbiota in aged mice, promoting beneficial bacterial changes. • LNX restores Acetatifactor muris , reducing Turicibacter sanguinis levels. • LNX increases Blautia and Bifidobacterium , linked to longevity and health.