Lactiplantibacillus plantarum Q7 relieves senescence by improving intestinal homeostasis in Caenorhabditis elegans

Abstract Objectives Intestinal aging is a core manifestation of systemic aging characterized by intestinal barrier dysfunction. Probiotics can modulate intestinal homeostasis to delay aging, whereas the mechanisms remain incompletely elucidated. Materials and Methods In this study, the anti-aging effects of Lactiplantibacillus plantarum Q7 on Caenorhabditis elegans cultured at 20 °C were explored through a multi-dimensional analysis of intestinal homeostasis. Results The results demonstrated that the mean lifespan of C. elegans in the L. plantarum Q7 group reached 22.44 ± 2.86 d, representing a 44.12% extension compared with that of the E. coli OP50 group. L. plantarum Q7 intervention significantly reduced intestinal lipofuscin accumulation and enhanced intestinal barrier integrity. Furthermore, it reshaped the intestinal microbiota by displacing Escherichia coli to Limosilactobacillus fermentum and Lactiplantibacillus plantarum, establishing a more stable and advantageous microecosystem. It also increased the levels of acetic acid and isobutyric acid and shifted the intestinal metabolic profile from protein fermentation dominance to carbohydrate fermentation dominance. At the molecular level, L. plantarum Q7 intervention upregulated the expression of genes involved in autophagy initiation (unc-51, atg-18, and lgg-1), antioxidant defense (sod-3, gst-4, and rnr-2), and intestinal barrier function (ajm-1, dlg-1, hmp-1, and hmp-2). Correlation analysis further revealed a significant positive correlation network among microbiota composition, short-chain fatty acid metabolites, and host gene expression, indicating a potential interconnected network underpinning the anti-aging effects of L. plantarum Q7. Conclusions This study revealed the anti-aging mechanisms of L. plantarum Q7 through regulating intestinal homeostasis, providing a scientific basis for developing targeted probiotic anti-aging intervention strategies.