Research into the link between cognitive health and the gut microbiome has also led to the development of potential treatments and interventions.

“There has been a surge of interest in how specific bacteria may affect the brain, also known as psychobiotics,” Dr Gill points out. “In terms of where the science is at, some research groups have identified a number of promising candidates.”

These ‘candidates’ include species from the bifidobacteria family, a group of bacteria which digests dietary fibre and helps to prevent infection, among other roles. Research into bifidobacteria has shown it could play a role in the regulation of anxiety, mood, cognition and pain.

The types of bacterial deficiencies observed in those with memory issues could also lead to targeted interventions. “When it comes to conditions like Alzheimer’s and mild cognitive impairment (MCI), some studies have found that changes in the types of bacteria living in our guts could be linked to these diseases,” Dr Nagalingam explains.

“For example, people with MCI seem to have lower levels of certain bacteria like ruminococcus and butyricimonas. These changes in gut bacteria seem to be connected to how well our brains work, especially when it comes to things like attention and problem-solving.”

Can your gut health help to protect you from dementia? Here’s what the experts say