Many herbivorous small mammals are limited by low-quality food and body size, and they often cannot get enough energy and nutrients to meet their metabolic and nutritional needs. Coprophagy, a popular behavior to eat feces of their own and others, can help some herbivores rodents reabsorb the nutrients, and provide some essential amino acids, vitamin B and vitamin K as well.

On July 6, 2020, the Animal Physiological Ecology Group of Institute of Zoology, Chinese Academy of Sciences, published their new research results in the ISME journal entitled "Coprophagy prevention alters microbiome, metabolism, neurochemistry, and cognitive behavior in a small mammal” （https://doi.org/10.1038/s41396-020-0711-6）. Their study showed that the coprophagy of Brandt’s vole (Lasiopodomys brandtii) could regulate metabolism, neurochemistry, and cognitive behavior by changing gut microbiota (Fig. 1). This is another one of new findings demonstrating the function of gut microbiota in regulating host metabolism in wild small mammals, after two other papers showing that huddling improves gut microbial community and confers host energy benefit to defense cold (Zhang et al. 2018 Microbiome) and gut microbiota-norepinephrine crosstalk regulates thermogenesis during cold acclimation (Bo et al. 2019, ISME J), from the lab of Professor Dehua Wang.

Figure 1: Coprophagy affects the gut microbiota and cognitive behavior of Brandt's voles.

In this study, by preventing the behavior of coprophagy, they found that the coprophagy prevention influence the community structure of the gut microbiota in voles. Bacteroidetes increased while Firmicutes decreased, however, the structure and composition of gut microbiota will also be restored after the animals recover their coprophagy. They also found that during coprophagy prevention, voles were in a state of negative energy balance, voles decrease their body weight and increase food intake and changed the hormone and neurotransmitter levels. Further, they tested the memory of voles after preventing of coprophagy by Y-maze, and results showed that their memory was damaged.

In order to further explore whether the memory impairment caused by coprophagy prevention is related to the changes of gut microbiota, they targeted the SCFAs, the main metabolites of the gut microbiota, and they make artificial supplement of acetate to the voles which were prevented of coprophagy. They found that daily acetate administration was able to reverse some of the coprophagy prevention-induced changes in microbiota composition, metabolism, neurochemistry and cognitive behavior.

Therefore, they made the conclusion that coprophagy help to maintain the stable gut microbiota, promote microbial metabolites, maintain host energy balance, and benefit the host cognitive performance.

Bo Tingbei, a Ph.D student and associate professor Zhang Xue-Ying from the National Key Laboratory for Integrated Management of Agricultural Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences are the co-first authors of the paper, and Professor Wang Dehua, is the corresponding author. This research was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Beijing.

Link to the paper： Bo Ting-Bei, Zhang Xue-Ying, Kevin D. Kohl, Wen Jing, Tian Shuang-Jie and De-Hua Wang. 2020. Coprophagy prevention alters microbiome, metabolism, neurochemistry, and cognitive behavior in a small mammal. The ISME Journal (https://doi.org/10.1038/s41396-020-0711-6)