外刊阅读20241228｜这两个年龄段最容易出现断崖式衰老！

+

上期划线句答案

+

本期内容

◆

双语阅读

The progress of a human being through life might be thought of as a mostly gradual succession of changes from the ovum to the grave. But if you wake up one morning, look in the mirror, and wonder when you suddenly grew so much older, you may not be imagining things. Snyder and his colleagues have been investigating the biology of aging to better understand what changes occur and how, in order to better mitigate and treat these ailments . To this end, they have been tracking a group of 108 adults, who have been donating biological samples every few months over several years.

Using the samples from their cohort, the researchers have been tracking different kinds of biomolecules. The different molecules studied include RNA, proteins, lipids , and gut, skin, nasal , and oral microbiome taxa , for a total of 135,239 biological features. Each participant submitted an average of 47 samples over 626 days, with the longest-serving participant submitting 367 samples. This wealth of data resulted in more than 246 billion data points, which the researchers then processed, looking for patterns in the changes.

Several previous studies have found non-linear changes in molecular abundances that can be linked to aging in rats and humans. Studies of fruit flies, mice, and zebrafish have also pointed to a stepwise aging process in those species. Snyder and his colleagues noticed that there's a very clear change in the abundance of many different kinds of molecules in the human body at two distinct stages.

Around 81 percent of all the molecules they studied showed changes during one or both of these stages. Changes peaked in the mid-40s, and again in the early 60s, with slightly different profiles. The mid-40s peak showed changes in molecules related to the metabolism of lipids, caffeine, and alcohol, as well as cardiovascular disease, and dysfunctions in skin and muscle.