Why does coffee make us poop? Scientists may have found the answer

It’s a morning ritual for millions: a couple of cups of coffee followed by a couple of poops.

Pranjal Mehar of Tech Explorist reports that one study found that 29% of participants needed to use the bathroom within 20 minutes of drinking a cup of coffee.

But why?

In the search for the appropriated answer, scientists in Texas fed rats coffee with gut bacteria in Petri dishes. They found that coffee suppressed bacteria and increased muscle motility, regardless of caffeine content.

Scientists additionally examined changes to bacteria when the fecal matter was exposed to coffee in a petri dish, and by studying the composition of feces after rats ingested differing concentrations of coffee over three days. The study also documented changes to smooth muscles in the intestine and colon, and the response of those muscles when exposed directly to coffee.

The study found that growth of bacteria and other microbes in fecal matter in a petri dish was suppressed with a solution of 1.5 percent coffee, and growth of microbes was even lower with a 3 percent solution of coffee. Decaffeinated coffee had a similar effect on the microbiome.

Xuan-Zheng Shi, Ph.D., lead author of the study and associate professor in internal medicine at the University of Texas Medical Branch, Galveston said, “When rats were treated with coffee for three days, the ability of the muscles in the small intestine to contract appeared to increase. Interestingly, these effects are caffeine-independent, because caffeine-free coffee had similar effects as regular coffee.”

After the rats were fed coffee for three days, the overall bacteria counts in their feces were decreased. According to scientists, further study is required to determine whether these changes favor firmicutes, considered “good” bacteria, or enterobacteria, which are regarded as negative.

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.

This entry was posted in Wacky and Weird and tagged , , , by Douglas Powell. Bookmark the permalink.

About Douglas Powell

A former professor of food safety and the publisher of barfblog.com, Powell is passionate about food, has five daughters, and is an OK goaltender in pickup hockey. Download Doug’s CV here. Dr. Douglas Powell editor, barfblog.com retired professor, food safety 3/289 Annerley Rd Annerley, Queensland 4103 dpowell29@gmail.com 61478222221 I am based in Brisbane, Australia, 15 hours ahead of Eastern Standard Time