How Aging Affects the Gut Microbiome
Scientists have also theorized that changes to the gut microbiome from normal aging have a direct effect on the central nervous system (CNS), potentially contributing to the decline in cognitive function seen in the elderly. But their theory had yet to be tested, until recently. Scientists from the United Kingdom and Italy carried out a fecal microbial transplant (FMT) on healthy old mice and transferred the microbes to healthy young adult mice. For comparison they also carried out a fecal microbial transplant from young mice to others of the same age. Following FMT they examined the gut microbiome and the brain’s hippocampus, a key memory and learning center, and also conducted a battery of cognitive and behavioral tests on the laboratory animals. The scientists found FMT from old donors led to impaired spatial learning and memory similar to that experienced by aged mice. In the hippocampus, altered expression of proteins took place. This had a negative effect on synaptic plasticity, the ability of neurons to adapt or modify their connections as needed over time. Synaptic plasticity is crucial to retain memory and learning abilities.Young Brain Cells Look Old
Some of the cells in the brain’s hippocampus also acquired characteristics of aging; they looked like old cells. The final observation was a reduction in gut bacteria that produce short-chain fatty acids. These have major health benefits including a boost in the well-being of the brain and central nervous system. This was the first study to provide evidence that FMT significantly affects important cognitive functions of the central nervous system in aging.Potential to Reverse Brain Aging in Humans
Although the scientists transferred fecal microbes from old to young adult mice, they believe the effects would apply in reverse when transferring fecal microbes from young to old humans. The research team concluded that "approaches that aim to restore a young-like microbiota might improve cognitive function, and in so doing, the quality of life of the elderly...." Lead author of the study, Dr. David Vauzour, explained, "Research has shown that the aging process may be linked with age-related changes in our gut microbiota. "...fecal transplantation from an old donor to a young recipient causes an age-associated shift in the composition of gut microbiota...the young mice began to behave like older mice, in terms of their cognitive function." Another member of the research team, Prof. Arjan Narbad, added, "Manipulating the microbiome is increasingly being seen as a way of improving or maintaining human health, and these results are an exciting indication of its potential for helping us age healthily." Of course, the research is still in the laboratory stage, but FMT is showing great promise in the treatment of other illnesses in people.FMT is Already in Use
Fecal microbial transplants are already used in children and adults who suffer from debilitating gastrointestinal illnesses, such as C.diff (Clostridium difficile), an antibiotic-resistant strain of bacteria. However, FMT is still considered “investigational” by the FDA. In people, FMT is a procedure that delivers healthy human donor stool to the patient via a colonoscopy, an enema, a nasogastric tube or in capsule form, popularly called “poop pills.” Some pills containing “clean” fecal bacteria from donors are in development as prospective prescription drugs. FMT works by repopulating the microbiome of your gastrointestinal tract with thousands of bacteria that keep the body healthy. In addition to research into using FMT against dementia, scientists are exploring its use against peanut allergies. In a clinical trial at Boston Children’s Hospital, researchers are looking at whether giving peanut-allergic people the “good” bacteria from a non-allergic person in a “poop pill” prevents allergic reactions. There are also some 170 clinical trials underway across the nation using FMT to treat other illnesses, among them type 2 diabetes, cirrhosis of the liver and HIV. FMT is not without risk. In the spring of 2019, a 73-year-old man with a unique blood condition became the first person to die following FMT. After the man’s death, scientists found out his “poop pills” had contained a rare type of E. coli bacteria that was drug resistant.- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532115/
- https://www.uea.ac.uk/news/-/article/could-a-poo-transplant-one-day-be-the-secret-of-eternal-youth-
- https://www.statnews.com/2019/10/30/details-first-death-fecal-transplant/
- https://www.childrenshospital.org/conditions-and-treatments/treatments/fmt
