BACKGROUND: The gut-brain axis links intestinal microbiota with emotional health, a critical concern in aging populations experiencing gut dysbiosis.
OBJECTIVE: This study aimed to evaluate whether supplementation with Pediococcus acidilactici PA53, through modulation of the gut microbiota, could improve emotional well-being in healthy older adults.
METHODS: In an 8-week randomized, double-blind, placebo-controlled trial, 75 older adults (aged 55-70) received either a placebo (maltodextrin) or PA53 (maltodextrin + 30 billion colony-forming units [CFU]/day). Fecal microbiota (16S ribosomal RNA [rRNA] sequencing) and serum biomarkers (enzyme-linked immunosorbent assay [ELISA]) were assessed at baseline and week 8. Data were analyzed using t-tests/non-parametric tests and permutational multivariate analysis of variance (PERMANOVA), with p<0.05 considered statistically significant.
RESULTS: After 8 weeks, the PA53 group showed statistically significant improvements in happiness (Memorial University of Newfoundland Scale of Happiness [MUNSH]: 33.75 vs. 38.05, +12.7%, p<0.05), gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale [GSRS]: 17.50 vs. 15.83, -9.5%, p<0.001; Bristol Stool Scale [BSS]: 2.50 vs. 3.20, +28%, p<0.01), and sleep quality (Pittsburgh Sleep Quality Index [PSQI]: 5.62 vs. 4.33, -23.0%, p<0.05). Although perceived stress (PSS) scores in the PA53 group decreased from 38.21 to 36.94 (-3.3%), this within-group change lacked statistical significance, despite showing a significant between-group advantage over the placebo. Serum IL-6 and tumor necrosis factor-alpha (TNF-α) decreased significantly (IL-6: 135.6±35.2 to 108.4±26.0 pg/mL; TNF-α: 65.8±19.5 to 54.2±15.9 pg/mL), while interleukin-25 (IL-25) increased (48.8±16.3 to 68.5±14.9 pg/mL) (p<0.001). PA53 intervention significantly altered the relative abundance of Bacillota (p<0.05) and increased beneficial genera including Ruminococcus(1.1% to 2.2%), Lachnospiraceae ND3007 group, Blautia (7.6% to 11.4%), and Faecalibacterium (increased from 6.9% to 10.6%).
CONCLUSION: PA53 supplementation illustrated beneficial effects on fecal microbiota and well-being in elderly individuals, suggesting its potential as a probiotic intervention.
Gut-Brain Axis