Duke Health Logo Statin drugs are known to lower cholesterol, but why is it that they work for some and not for others? A study by Duke University scientists has unraveled 3 bile acids generated by gut bacteria found in individuals with good response to a common cholesterol lowering drug known as simvastatin.

The results show how gut bacteria could innately influence the way people absorb, process and take advantage of such medicines.

“This is personalized medicine — the effects of drugs and how we respond. We found that the benefit of statins could be partly related to the type of bacteria that lives in our guts. The reason we respond differently is not only our genetic makeup, but also our gut microbiome,” remarked lead author Rima Kaddurah-Daouk, PhD, an associate professor in Duke’s Department of Psychiatry and leader of the Pharmacometabolomics Network.

For the analysis, information was collected from a group of participants from a national project namely Cholesterol and Pharmacogenetics (CAP) study. The test where smaller gut bacteria were examined, the team found almost 100 people whose LDL levels dropped significantly by consuming simvastatin while 24 seemed to have good response while another set of 24 persons appeared to show less benefit.

The analysts then examined the blood work from the subjects before consumption of any drug while locating bile acids and fat-like matter such as sterols which play a role in body’s break down and cholesterol use.

The aforesaid 3 bile acids seemed to have contributed to strong responses found in some participants. These acids are synthesized by a specific gut bacteria usually referred as storehouses of chemicals that are responsible for a state of health. Also, 5 different bile acids were found among individuals who responded weakly to statin.

The investigators believe that since bile acids and statins use a common transport pathway that leads to the liver and intestines, they seem to compete for the travel. This tends to result in less or more kinds of bile acids that apparently enhance or dampen the effects of the drug.

The scientists conclude that screening of certain bile acids may pave the path for gauging the variation in reactions to simvastatin. Furthermore, new ways to regulate the gut microbiome through probiotics to trigger various gut bacteria will supposedly accelerate the responses of the drug.

The findings are published in the journal, PLoS ONE.