Effects of ellagitannin rich berries on blood lipid profiles, gut microbiota and metabolism of phenolic compounds in metabolic syndrome

Scope: Ellagitannins are polyphenols abundant in strawberries, raspberries and cloudberries. The effects of a mixture of these berries were studied in subjects with features of metabolic syndrome. The study focused on cardiovascular risk factors, gut microbiota and ellagitannin metabolites. Methods and Results: Twenty subjects consumed 300 g of ellagitannin rich berries daily for 8 weeks ina randomized controlled trial. A control group, with twelve subjects, ate no berries. Most measured variables did not differ between the two study groups. However, minor positive alterations were observed in systolic blood pressure, LDL cholesterol, 8-isoprostane, TRAP and resistin. Statistical modelling of lipidprofiles pinpointed a group of 20 lipids for sample separation, indicating that they may be responsible for known positive health effects of berries. Berry supplementation caused changes to microbiota in 35% of the subjects. All these changes were related to either Families of Ruminococcaceae or Lachnospiraceae,which are the main butyrate-producing bacteria in the human colon. A majority of the subjects in the berry group were identified as urolithin producers.Conclusions: Ellagitannin rich berry supplementation may have positive effects on serum lipid profiles and on gut microbiota, which might modify bioavailability of the berry ellagitannins. Future studies in humans are warranted