Seasonal shift of the gut microbiome synchronizes host peripheral circadian rhythm for physiological adaptation to a low-fat diet in the giant panda

Characteristics of the gut microbiome vary synchronously with changes in host diet. However, the underlying effects of these fluctuations remain unclear. Here, we performed fecal microbiota transplantation (FMT) of diet-specific feces from an endangered mammal (the giant panda) into a germ-free mouse model. We demonstrated that the butyrate-producing bacterium Clostridium butyricum was more abundant during shoot eating season than during the leaf-eating season, congruent with the significant increase in host body mass. Following season-specific FMT, the microbiota of the mouse model resembled that of the donor, and mice transplanted with the microbiota from the shoot-eating season grew faster and stored more fat. Mechanistic investigations revealed that butyrate extended the upregulation of hepatic circadian gene Per2, subsequently increasing phospholipid biosynthesis. Validation experiments further confirmed this causal relationship. This study demonstrated that seasonal shifts in the gut microbiome affect growth performance, facilitating a deeper understanding of host-microbe interactions in wild mammals.

Automated summary

The gut microbiome varies with changes in host diet, and these variations may have important effects on host growth and development. In this study, fecal microbiota transplantation (FMT) was performed using diet-specific feces from giant pandas into germ-free mice. The results showed that the abundance of the butyrate-producing bacterium Clostridium butyricum was higher during the shoot eating season compared to the leaf-eating season, and this was consistent with the significant increase in host body mass. Mechanistic investigations revealed that butyrate extended the upregulation of the hepatic circadian gene Per2, subsequently increasing phospholipid biosynthesis.