The work here might be taken as an indication of the importance to aging of chronic inflammation and breakdown of the intestinal barrier generated in part by changes in the gut microbiome. Oral supplementation with the enzyme intestinal alkaline phosphatase (IAP) reduces both of these issues, and the result is mice that exhibit a slowed aging and lesser degrees of age-related frailty.
It's now accepted that gut-barrier dysfunction and gut-derived chronic inflammation play a role in human aging, but how that process is regulated is still largely a mystery. Studying mice and fruitflies, researchers found that the enzyme intestinal alkaline phosphatase (IAP) helped prevent intestinal permeability and gut-derived systemic inflammation, resulting in less frailty and extended life span. "Oral IAP supplementation in older mice significantly preserved gut barrier function and was associated with preserving the homeostasis of the gut microbiota during aging. In other words, the enzyme maintained the composition of the gut bacteria and controlled the low-grade chronic inflammation that can happen with aging."
Because the scientists were using animal models, they were able to test blood from the portal venous system, which goes from the GI tract into the liver and then on through the rest of the body. This gave a more direct measure of what is passing across the gut barrier than blood from a human arm would provide. Previous research suggests that IAP blocks an endotoxin called lipopolysaccharide (LPS). Because IAP is a naturally occurring enzyme that almost entirely remains in the gut rather than traveling throughout the system, researchers believe it should prove nontoxic to humans, and those who are found to have low levels, especially as they age, will simply be able to supplement.