Nicotinamide adenine dinucleotide replenishment rescues colon degeneration in aged mice

Boosting the level of a coenzyme regulating metabolism could help treat constipation and other aging-related intestinal problems. Researchers in Hangzhou, China, led by Qinsong Sheng from the First Affiliated Hospital of Zhejiang University and Zhenyu Ju from Hangzhou Normal University studied differences in colon function between young and old mice. They showed that older animals had more difficulty in defecation through the gastrointestinal tract and that this was associated with a lower level of the coenzyme nicotinamide adenine dinucleotide (NAD). Treatment with an NAD precursor improved defecation ability, whereas administering a drug that blocks NAD synthesis led to worsened colon function in mice. These findings point to NAD as a key regulator of colon motility and suggest a therapeutic strategy for older individuals with bowel-movement problems.