Your gut bacteria may determine how statins work…or don'tStatins are a very handy and popular class of drugs that reduce cholesterol levels and lessen a patient’s risks of cardiovascular disease (stroke and heart attack).

Well-known brands of statin drugs like simvastatin (Zocor), rosuvastatin (Crestor) and atorvastatin (Lipitor) can be an advantage to human health when they work properly. Unfortunately, statins don’t work for everyone, and a 2011 study published in PLOS ONE suggests a gut bacteria link may explain why.

Overall, data collected from 148 patients enrolled in the nationwide Cholesterol and Pharmacogenetics (CAP) study who had taken simvastatin were reviewed by a research team led by a Duke University scientist.

In addition to examining health data from 100 patients whose LDL cholesterol dropped dramatically thanks to taking simvastatin, researchers also reviewed results from 24 patients who derived little benefit from the statin drug and an equal number whose response was deemed “fairly good.”

Scientists collected blood work before any patients had taken a statin to identify signs of specific bile acids and sterols (fat-like substances connected to the use and breakdown of cholesterol).

Three kinds of bile acids produced by specific gut bacteria were found in samples taken from patients who responded well to statins for six weeks. On the other hand, five different kinds of bile acids were produced in patients whose bodies didn’t respond well to statins.

The difference between both groups: because bile acids and statins share the same pathways (to the intestines and liver) and compete for dominance, scientists speculate that patients whose bodies produce too many bile acids prevent statins from reaching their intended target—the liver—where the production of cholesterol is controlled.

Researchers believe a blood test that screens for bile acids could determine who responds well to simvastatin and who doesn’t.

“It’s no doubt that metabolites from bacteria are playing an important role in regulating our systems,” said lead researcher Dr. Rima Kaddurah-Daouk at Duke University School of Medicine in a press release. “We’re at a very early stage of understating this relationship, but eventually we could take a quick chemical assay and get a read on where we are metabolically.”

A more recent study supporting these findings concluded increasing bile salt hydrolase (proteins produced by gut bacteria that alter the chemical properties of bile acids) may slow down weight gains and serum cholesterol in mice.

In both studies, researchers cited probiotics as a possible solution to lower cholesterol, another reason among many to protect and enhance the diversity of beneficial bacteria in your gut by taking a multi-species probiotic like EndoMune Advanced Probiotic.