Despite the fact that it is a common condition, postoperative constipation or ileus remains poorly understood and has no established definition, etiology, or treatment. In an attempt to find a solution that quickly restores normal contractile movement of the intestines after surgery, researchers at the University of Texas used a rat model to demonstrate the in vivo and in vitro effects of coffee on gut microbiota and smooth muscle contractility.
They fed coffee to rats directly and mixed coffee with gut bacteria in petri dishes. Their findings indicated that coffee suppressed bacteria and increased muscle motility. After the rats were treated with coffee, total bacteria count in feces decreased and the ability of the muscles in the small intestine to contract increased. Xuan-Zheng Shi, lead author of the study, pointed out “Interestingly, these effects are caffeine-independent, because caffeine-free coffee had similar effects as regular coffee.”
The investigators in Shi’s study observed changes in bacteria when fecal matter was exposed to coffee in a petri dish and changes in rat feces after the ingestion of different concentrations of coffee over three days. Changes to smooth muscles in the intestine and colon and the response of muscles exposed directly to coffee were documented. Muscles in the lower intestine and colon contracted more readily after a period of coffee ingestion. In petri dishes, the growth of bacteria and other microbes in fecal matter was suppressed when a solution of 1.5 percent coffee was applied and growth slowed further with a 3 percent solution. As Shi noted above, decaffeinated coffee had a similar effect on the microbiome.
Researchers have yet to identify the specific mechanism by which coffee increases bowel movement. Further study is necessary to determine whether the decline in total bacteria count in feces helps good bacteria or bad bacteria. Favorable bacteria such as Firmicutes are relatively more efficient at breaking down complex carbohydrates, including cellulose, pectin, and xylan as well as host-derived carbohydrates at the protective mucous layer of the intestine. Increasing the ratio of these bacteria in the gut microbiome leads to higher efficiency in the storage of metabolic byproducts.
Additional clinical research is needed to ascertain whether coffee intake is effective for ileus, a temporary arrest of normal contractile movement of the intestines caused by abdominal surgery. A poorly understood postoperative outcome with mechanisms that are neurogenic, inflammatory, and pharmacological in nature, ileus presents significant clinical challenges and lacks effective management strategies. Failure to restore adequate bowel function after surgery causes complications, including infection and intestinal adhesion, which may prolong hospitalization and increase patient distress. Coffee therapy may hold some hope.
Kerilyn Sappington is the founder of Integrative Translations, which specializes in Chinese-to-English medical translation of conventional and complementary medicine.