The intestines recover worse with age

In young animals, proteostasis persists even after injury. But in the old intestine, everything goes differently: cells begin to accumulate incorrect, broken proteins, experience stress and repair tissue worse. All this greatly interferes with normal healing and makes the intestines especially sensitive to stress and diseases.

The key clue turned out to be polyamines, small molecules that are involved in cell growth and protein health. It has been noted that in the old intestine, polyamines rise sharply after damage, as if the body itself is trying to turn on the recovery system. But this is not enough.

When researchers further enhanced polyamine metabolism — through nutrition or direct addition of polyamines — the intestines of old animals began to heal almost as quickly as those of young ones. The functioning of protein systems improved, cellular stress decreased, and the epithelium began to recover more actively.

And if the polyamine pathway was blocked, on the contrary, aging worsened: healing slowed down, and damage increased. It has been proven that the aging intestine does not lose its ability to recover — it simply lacks the right molecular signal that triggers regeneration processes.

It was especially interesting to observe that even a short restriction of nutrition, and then a return to regular food, also activated polyamine metabolism and helped the intestines recover faster. Such data may open up the possibility of mild dietary approaches for the elderly.

It is emphasized that polyamines can become a new direction in the fight against age-related decline in the body’s regenerative abilities, not only in the intestines, but possibly also in the skin or liver. However, before using such methods in humans, it is necessary to study safety: polyamines are associated with active cell growth, which means it is important to make sure that they do not increase the risk of cancer.

Nevertheless, the researchers are confident that their work shows an important principle: even in old age, tissues retain the potential for renewal, and it can be awakened if given the right boost.