Purple lettuce (Lactuca sativa L.) attenuates metabolic disorders in diet induced obesity

Purple lettuce (Lactuca sativa L.) is a type of low caloric vegetable often consumed freshly, whereas its function in metabolic control has been little studied. To investigate the protective effect of a type of purple lettuce against metabolic risk factors, we treated the C57BL/6J DIO mice with or without purple lettuces for 8 weeks. Results showed that purple lettuce effectively attenuated many metabolic risk factors in DIO mice. Typically, purple lettuce prevented the body weight gain by reducing fat mass accumulation and increasing energy expenditure. Additionally, consumption of purple lettuces enhanced glucose homeostasis, increased insulin sensitivity and improved the lipid profile in the DIO mice. This was, at least partly, attributable to its abundance of bioactive molecules like esculin and chlorogenic acid. High intake of purple lettuces modulated the intestinal microbiota composition like decreased Lachnospiraceae. We conclude that purple lettuce has great potential as functional foods in prevention of metabolic disorders.