Yuka Sasakawa^{1, 2,}, Akari Kominami^{1, 2}, Michiyo Abe^{1, 2}, Kaori Yamamoto², Mayumi Nakao², Fumiko Nakaoka², Shigetoshi Okumura^{2, 3}, Lekh Raj Juneja^{2, 3}, Jun Kunisawa¹

It has been reported that Glycyrrhiza uralensis (Ural licorice) extract, with the brand name “LICONINE^®”, at an intake level of low risk (human equivalent to less than 1 g licorice per day) had anti-obesity and anti-inflammatory effects on high-fat high-sucrose (HFS) diet-induced obese mice, but the effect of LICONINE on the fecal microbiota has not been clarified. In the present study, effects of LICONINE versus Ural licorice at intake levels of low risk on the fecal microbiota Bacteroidetes and Firmicutes were examined in HFS diet-induced obese mice. The results demonstrated that consumption of LICONINE was associated with higher decrease in the body weight and visceral fat weight than those with Ural licorice. The results also demonstrated that the Firmicutes to Bacteroidetes ratio in the feces was decreased more with LICONINE than with Ural licorice, and that the body weight and visceral fat weight were correlated with the Firmicutes to Bacteroidetes ratio in HFS diet-induced obese mice. These results indicate that LICONINE, at an intake level of low risk, may reduce obesity through the normalization of the fecal microbiota disturbance. In summary, at the intake level of low risk, LICONINE is more effective than Ural licorice for treating obesity and fecal microbiota disturbance. Further research is needed to identify the mechanisms underlying the effects of LICONINE on fecal microbiota.

glycyrrhiza uralensis, ural licorice extract, LICONINE, high-fat high-sucrose diet-induced obese mice, obesity, microbiota