It's official. Fecal transplants can successfully reverse aging in mice

By no means is this a recipe for eternal youth. However, as we age, we become more susceptible to disease, partly because our guts degrade over time. Although only mice guts have been tested so far, these experiments suggest something can be done to deal with that problem.

An unlikely way to reverse the clock 

The community of bacteria that we carry around in our gut, generally known as the gut microbiota, has long been connected to our health. In fact, changes in the kinds and behavior of bacteria, viruses, fungi, and other microorganisms in an individual's gut can be linked to a majority of illnesses.

For example, these changes in microbiota composition can occur as humans age, which has been linked to age-related ailments such as inflammatory bowel disease, cardiovascular, autoimmune, metabolic, and neurodegenerative diseases. 

In order to understand the implications of these changes in microbiota that occur as humans age, a team of scientists from Quadram Institute transplanted gut microbes from older mice into healthy young mice and vice versa and looked at how this affected inflammatory markers of aging in the gut, brain, and eye, all of which suffer from deteriorating function with old age.

Reversing aging with young donor microbiota

The researchers discovered that the microbiota from aged donors caused a loss of integrity of the stomach lining, allowing bacterial metabolites to enter the blood and triggering the immune system and inflammation in the brain and eyes, according to the study published in the journal Microbiome. Moreover, inflammaging, or age-related chronic inflammation, has been linked to the activation of particular immune cells located in the brain, and these cells were likewise overactive in young mice given older microbiota transplants.

"Our results demonstrate that the age-associated changes in the murine intestinal microbiota contribute to disrupted gut barrier integrity and systemic and tissue inflammation affecting the retina and the brain, but these changes can be reversed by replacement with young donor microbiota," the researchers wrote.

Next, the team will work on determining how long these positive effects can last, as well as identifying the beneficial components of the young donor microbiota and how they affect organs other than the gut. Then scientists can begin to explore whether the technique would work in people as well.