Gannan navel orange and Jinggang pomelo, belonging to the genus Citrus, are good sources of phenolic compounds, which are mainly concentrated in the peel. These phenolic compounds are considered promising in the prevention and treatment of non-alcoholic fatty liver disease (NAFLD). In order to maximize nutrients retention and bioactivity in the peel, pomelo peel and orange peel were processed using freeze-drying technology and mixed in the ratio (pomelo peel powder 50% and orange peel powder 50%) to make citrus peel powder (CPP). The purpose of this study was to explore new strategies and mechanisms associated with the consumption of CPP to alleviate nonalcoholic fatty liver injury, lipid metabolism disorders, and gut microbiota dysbiosis in obese mice induced by high-fat diet (HFD). The results showed that after 12 weeks of CPP administration, CPP supplementation had a strong inhibitory effect on HFD-induced weight gain, hepatic fat accumulation, dyslipidemia, and the release of pro-inflammatory cytokines. In particular, CPP modulates the composition of the intestinal flora, such as increasing the relative abundance of phylum Firmicutes, genus Faecalibaculum, genus Lactobacillus, genus Dubosiella, and genus Lachnospiraceae_NK4A136_ group and decreasing the relative abundance of phylum Bacteroidota, genus Helicobacter, and genus Bacteroides. These results suggest that CPP has a preventive effect on NAFLD, which can be related to the regulation of intestinal flora.

The chestnut, belonging to the Angiosperm family Fagaceae, is a crop mainly consumed in North America, Europe, and East Asia. The Chinese, European, North American, and Korean/Japanese chestnut are the four main varieties Ertürk et al., 2006;Otles & Selek, 2012). Chestnuts are considered an important tree species to the agriculture and forestry economies, and the chestnut fruit has been one of the most important food resources in rural areas of Europe for many centuries (Squillaci et al., 2018). As a traditional food, chestnuts are usually eaten fresh, cooked, steamed, roasted, boiled, or fried (Ozcan et al., 2017). Moreover, the food industry also utilizes a large number of techniques to obtain different chestnut products such as