Doctors have known for some time that faecal matter is a window to the trillions of good and bad bacteria, viruses and fungi living in the intestines, collectively known as the gut microbiome. What a layman may describe as a poo transplant - taking faecal bacteria from donors, processing them and inserting them into the patient's gut either orally or through a colonoscopy - has been used to successfully treat Clostridium difficile infection, which causes recurrent severe diarrhoea and colon inflammation.
The transplanted faecal matter restores the patient's gut microbiome by introducing healthy bacteria. Beyond keeping the gut healthy, the microbiome is known to impact the brain as well. Although they are far away from each other, the stomach and the brain have a two-way communication known as the brain-gut axis. Now, scientists in Europe have found that faecal matter is hiding clues related to ageing and cognition.
A primal connection exists between our brain and our gut. We often talk about a “gut feeling” when we meet someone for the first time. We're told to “trust our gut instinct” when making a difficult decision or that it's “gut check time” when faced with a situation that tests our nerve and determination.
The tangled tau protein, which is prevalent in those with Alzheimer's disease, saw an uptick in the young mice, said Dr Vauzour. The study was published in the journal Microbiome last month. The research's other co-lead, Associate Professor Claudio Nicoletti of the University of Florence, said: "This work provides a strong rationale to devise therapies aiming to restore a young-like microbiome to improve cognitive functions and quality of life in the elderly."
The European team is now studying older mice transplanted with the faecal matter of young mice.
The team is also discussing with a centre in the Netherlands about similar research with primates.
Dr Nicoletti said: "If you improve cognition or other functions in old monkeys, chances are you can do the same in humans.
"If we see very positive results in the current mice study, we can start clinical trials on humans within two years."