Gut microbiome interventions may improve cognitive function in older adults

15th October 2026 – by TwisnUK

Modifying the gut microbiome may help improve cognitive function in older adults, according to a new systematic review and meta-analysis led by researchers including Mary Ni Lochlainn from the Department of Twin Research and Genetic Epidemiology at King’s College London. 

Published in Age and Ageing, the study reviewed evidence from 14 studies involving older adults and found that interventions targeting the gut microbiome, including probiotics, prebiotics and synbiotics, were associated with improvements in several areas of cognitive function. 

The gut microbiome is increasingly recognised as playing a role beyond digestion, with communication between the gut and brain occurring through immune, metabolic, hormonal and neural pathways. This relationship, known as the gut-brain axis, may influence cognition and brain health. 

The researchers reviewed randomised controlled trials and other intervention studies involving adults aged 60 and over. Of the 14 studies included, 13 were randomised controlled trials, covering probiotic, prebiotic and synbiotic interventions. 

Nine studies reported significant improvements in at least one area of cognitive function, particularly global cognition, memory, attention and executive function. 

A meta-analysis of a subgroup of studies found a statistically significant improvement in global cognition scores following supplementation. 

Dr. Mary Ni Lochlainn, from the Department of Twin Research, Ageing and Genetic Epidemiology at King’s College London and author of the study, said: 

“Our findings suggest that targeting the gut microbiome could be a promising approach to supporting cognitive health in older adults. While more high-quality research is needed, the overall evidence points towards a potentially important link between the gut microbiome and cognitive ageing.” 

The strongest evidence for cognitive benefits was seen in cognitively healthy older adults and people with mild cognitive impairment. 

The researchers highlight that many of the interventions studied, including probiotics, prebiotics and synbiotics, are already widely available and are generally considered low risk. However, differences between studies and the limited number of high-quality trials mean that further research is needed before firm conclusions can be drawn about their effectiveness. 

The study adds to growing evidence that the gut microbiome may influence health beyond the gastrointestinal system and could provide a potential avenue for supporting healthy cognitive ageing. 

“Understanding how the gut microbiome interacts with the brain could open up new ways of thinking about healthy ageing. Our review brings together the current evidence and highlights both the promise of these interventions and the need for larger, well-designed studies.” 

The researchers conclude that gut microbiome modulation represents a promising and potentially affordable approach to supporting cognitive health in older people, but further high-quality research is needed to establish which interventions are most effective and for whom.