Most hardened coffee drinkers know that their morning cup can lead to a visit to the loo – but now scientists might know why.
Texas researchers found that rats treated with coffee suppressed bacteria and affected muscles – but it wasn't related to caffeine.
In fact, caffeine-free coffee had the same effect, the researchers say.
'When rats were treated with coffee for three days, the ability of the muscles in the small intestine to contract appeared to increase,' said Xuan-Zheng Shi, of the University of Texas Medical Branch, Galveston.
'Interestingly, these effects are caffeine-independent, because caffeine-free coffee had similar effects as regular coffee.'
Coffee has long been known to increase bowel movement, but researchers have not pinpointed the specific reason or mechanism.
Muscles in the lower intestines and colons of the rats showed increased ability to contract after a period of coffee ingestion, and coffee stimulated contractions of the small intestine and colon when muscle tissues were exposed to coffee directly in the lab.
The results support the need for additional clinical research to determine whether coffee drinking might be an effective treatment for post-operative constipation, or ileus, in which the intestines quit working after abdominal surgery, the authors said.
- This article first appeared on Yahoo
Read more from Yahoo News UK: