Individuals with obesity have an increased prevalence of the Bacteroides 2 (Bact2) enterotype, one of four classifications of gut microbiota composition that is associated with systemic inflammation and disease. However, individuals with obesity who are taking statin therapy have a lower prevalence of this dysbiosis than individuals with obesity who are not receiving statins. Causality has not been established, but the possibility that statin therapy might have gut microbiota-modulatory benefits should now be tested.

Alterations in gut microbiota have been linked with cardiovascular diseases, including atherosclerosis, heart failure and hypertension. In a new study, researchers analysed faecal samples from 888 individuals in the MetaCardis Body Mass Index Spectrum cohort. Among the individuals who were not taking statins, those with obesity (BMI ≥30) had a higher prevalence of the Bact2 enterotype (17.7%) than those who were lean or overweight (BMI <30; 3.9%). The Bact2 enterotype is characterized by a high proportion of Bacteroides and a low proportion of Faecalibacterium. Individuals with this enterotype tend to have loose stools and a higher plasma concentration of the inflammatory marker C-reactive protein than individuals with other enterotypes.

Credit: KATERYNA KON/SCIENCE PHOTO LIBRARY/GETTY

The researchers also found that individuals with obesity who were receiving statin therapy had a lower prevalence of the Bact2 enterotype (5.9%) than individuals with obesity who were not taking statins (17.7%). This finding was validated in an independent cohort of 2,345 individuals from the Flemish Gut Flora Project.

statin therapy might have gut microbiota-modulatory benefits

These findings raise the intriguing possibility that statin therapy might have a beneficial modulatory effect on the gut microbiota. However, causality cannot be determined from the data reported because, for example, statin users might also have engaged in other health-promoting behaviours. In an accompanying News & Views article, Peter Libby calls for “a large-scale clinical trial to determine whether statins lead to a reduced prevalence of the Bact2 enterotype in obese participants who would not otherwise receive statins”.