Lactobacillus reuteri attenuates cardiac injury without lowering cholesterol in low-density lipoprotein receptor-deficient mice fed standard chow. - GreenMedInfo Summary

Disruption of the normal gut microbiome (dysbiosis) is implicated in the progression and severity of myriad disorders, including hypercholesterolemia and cardiovascular disease. Probiotics attenuate and reverse gut dysbiosis to improve cardiovascular risk factors like hypertension and hypercholesterolemia. Lactobacillus reuteri is a well-studied lactic acid-producing probiotic with known cholesterol-lowering properties and anti-inflammatory effects. In the present study, we hypothesized that L. reuteri delivered to hypercholesterolemic low-density lipoprotein receptor knock-out (LDLr KO) mice will reduce cholesterol levels and minimize cardiac injury from an ischemic insult. L. reuteri (1x10or 50x10CFU/day) was administered by oral gavage to wild type mice and LDLr KO for up to 6 weeks followed by an ischemia-reperfusion (I/R) protocol. After 4 weeks of gavage, total serum cholesterol in wild type mice receiving saline was 113.5±5.6 mg/dl compared to 113.3±6.8 mg/dl and 101.9±7.5 mg/dl in mice receiving 1x10or 50x10CFU/day, respectively. Over the same timeframe, administration of L. reuteri at 1x10or 50x10CFU/day did not lower total serum cholesterol (283.0±11.1, 263.3±5.0 and 253.1±7.0 mg/dl; Saline, 1x10or 50x10CFU/day, respectively) in LDLr KO mice. Despite no impact on total serum cholesterol, L. reuteri administration significantly attenuated cardiac injury following I/R, as evidenced by smaller infarct sizes when compared to controls in both wild type and LDLr KO groups. In conclusion, daily L. reuteri significantly protected against cardiac injury without lowering cholesterol levels suggesting anti-inflammatory properties of L. reuteri uncoupled from improvements in serum cholesterol.