A gut bacterium as a fountain of youth? Well, let’s start with reversing insulin resistance - Orlando SentinelBut insulin resistance is also linked to a rogue’s gallery of ills, from obesity and inflammation to the sagging immunity and frailty that comes with advancing age. If a readily available means of slowing or reversing insulin resistance could be identified, it might have broad and powerful anti-aging effects (in addition to protecting some of the world’s 650 million adults who are obese against developing type 2 diabetes). First identified in 2004, Akkermansia muciniphila inhabits the large intestine and is thought to account for between 1% and 5% of all intestinal bacteria in adults. Scientists suspect it helps preserve the coat of mucus that lines the walls of our intestines. It may also play a role in making the polyphenols we eat in plant-based foods more available to our cells. Evidence is mounting that A. muciniphila is involved in obesity, glucose metabolism and intestinal immunity. For instance, a 2018 study of cancer patients suggests that it plays a role in immune response. Compared to patients who failed to be helped by a new generation of immunotherapy, those who did had a greater abundance of Akkermansia in their guts. When researchers took the stool of a patient who responded positively to the cancer-fighting therapy and transplanted it into lab animals with human cancers, the recipients became more likely to respond positively to the same treatment. In the new research, a team from the National Institute on Aging examined the molecular chain of events that appears to result from A. muciniphila’s depletion in mice and macaque monkeys. And they assessed the effects of restoring this gut microbe to elderly animals. First, they documented that the guts of older animals had markedly smaller populations of A. muciniphila than the guts of young animals, and that as A. muciniphila became more scarce, so did butyrate, one of the gut’s key protectors. The deficiency of these two substances caused the mucous walls of the of the aged animals’ intestines to thin and grow leaky. That corrosive process unleashed a chain of events that touched off inflammation, prompted an immune response and, in a final step, increased insulin resistance. Key to that final step was the accumulation in the gut of a specific kind of immune cell called 4BL cells. If the detrimental chain of events was to be disrupted, the accumulation of those 4BL cells probably had to be stopped, the researchers surmised. The researchers also documented what appeared to be a role for A. muciniphila in fostering healthy diversity among the garden of other microbes that colonize the gut. In animals with scant populations of A. muciniphila, a host of other common gut bacteria — as well as their beneficial byproducts, particularly butyrate — also suffered.