Crosstalk between gut microbiota and host lipid metabolism in a mouse model of alcoholic liver injury by chronic baijiu or ethanol feeding

A growing body of evidence highlights the important role of gut microbiota and host metabolism, particularly for lipid metabolism, in the development and progression of alcoholic liver disease (ALD). However, the effects of fermented alcoholic beverages on gut microbiota and host lipid metabolism remain under-investigated. Moreover, the crosstalk between gut microbiota and host lipid metabolism is still unclear in experimental ALD. Baijiu is a traditional Chinese alcoholic beverage. It contains large amounts of small molecule bioactive compounds in addition to a significant amount of ethanol (EtOH). In this study, we showed that baijiu caused lower degrees of liver injury than pure EtOH as revealed by phenotypic, biochemical and histologic analyses. Furthermore, baijiu and EtOH gavage resulted in different gut microbiota structures. Specifically, the baijiu group had a significantly higher abundance of Ruminococcus, Oscillospira, Mucispirillum, Bilophila, Parabacteroides and Odoribacter and a lower abundance of Helicobacter and Prevotella than that of the EtOH group. Using a targeted metabolomics approach, we also observed a greater than 19% increase of total hepatic free fatty acids (FFAs) after baijiu feeding and a 33% increase of hepatic FFAs after EtOH feeding. Baijiu feeding significantly increased total hepatic mono-unsaturated FAs (MUFAs). In contrast, polyunsaturated fatty acids (PUFAs), MUFAs and saturated FAs were significantly increased by EtOH feeding. Finally, Spearman's rank correlation showed that the increased levels of FFAs (mainly C20 and C22 unsaturated FAs) significantly correlated with key different gut microbiota, including a positive correlation with Desulfovibrio, Maihella, Helicobacter, Acholeplasma, Parasutterella, Prevotella, AF12 and Alistipes, and a negative correlation with Dorea, Olsenella, Adlercreutzia and Akkermansia. Our results suggest that compounds in baijiu attenuated the development of ALD and thus provided supporting evidence that the host-gut microbiota metabolic interactions play an important role in the development of ALD.