Data published in The Journal of Nutrition indicated that eight weeks of supplementation was also associated with decreases in markers of inflammation, including IL-6 and TNF-alpha.
“Pediococcus acidilactici PA53 emerges as a safe and effective intervention for enhancing digestive function and modulating inflammatory pathways in older adults,” wrote scientists from Henan University of Technology and the First Affiliated Hospital of Zhengzhou University. “Its ability to enrich beneficial microbiota while suppressing proinflammatory taxa aligns with mechanistic insights from animal studies.
“Regarding the GBA [gut-brain axis], although our findings suggest a preliminary potential for PA53 to positively influence certain aspects of mood and sleep, we acknowledge that not all psychological measures reached statistical significance. Therefore, these neuropsychological trends should be interpreted with caution.”
PA53
Pediococcus acidilactici PA53 is a strain developed, manufactured, and commercially supplied by China’s Wecare Probiotics.
Corresponding author Fei Xu said that, before this human trial, Wecare had developed a broader preclinical evidence package for PA53, including assessments of acid and bile tolerance, antimicrobial properties, antibiotic resistance, genomic safety, general safety, and animal-model effects.
“These studies provided the scientific basis for selecting PA53 for further clinical evaluation,” said Xu. “Some of this evidence is published, while some forms part of the company’s preclinical development data.”
While Wecare supplied the PA53 preparation and the matching placebo for the new study, the company did not fund the study, nor did it control the data or the decision to publish, said Xu.
“We therefore see the current study as an important addition to the PA53 evidence chain: the existing preclinical and safety work supported progression to human research, while this randomized, double-blind, placebo-controlled trial provides initial clinical evidence in older adults,” said Xu. “Because the trial was relatively small and lasted eight weeks, larger and longer-term studies will still be needed to confirm the durability and generalizability of the findings.”
Study details
The new randomized, double-blind, placebo-controlled trial included 75 healthy individuals aged between 55 and 70 (average age of 54.4). The participants were randomly assigned to receive either placebo or Pediococcus acidilactici PA53 at a daily dose of 30 billion colony forming units (CFUs) for eight weeks.
Data for the 69 participants who completed the study showed that the probiotic was associated with a 13% improvement in happiness, a 9.5% decrease in gastrointestinal symptoms, a 28% improvement in stool consistency (Bristol Stool Scale), and a 23% improvement in sleep quality.
Moreover, while levels of pro-inflammatory cytokines IL-6 and TNF-alpha decreased significantly, the anti-inflammatory IL-25 significantly increased, said the researchers. IL-25 has also been linked to mucosal repair in the intestine.
Looking at the composition of the gut microbiota, the researchers reported that PA53 supplementation led to a doubling in the abundance of beneficial Ruminococcus (from 1.1% to 2.2%). In addition, Blautia increased from 7.6% to 11.4% and Faecalibacterium increased from 6.9% to 10.6%.
“PA53 supplementation illustrated beneficial effects on fecal microbiota and well-being in elderly individuals, suggesting its potential as a probiotic intervention,” wrote the researchers.
Source: The Journal of Nutrition, Vol. 156, Issue 8, 101626, doi: 10.1016/j.tjnut.2026.101626. “Pediococcus acidilactici PA53 Improves Emotional Well-Being and Gut Health While Modulating Microbiota Composition in Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial”. Authors: Z. Wang, et al.
