Department of Integrative Biology and Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA.
Research School of Biology, The Australian National University, Canberra, ACT, Australia.
Mol Ecol. 2020 Jun;29(12):2300-2311. doi: 10.1111/mec.15476. Epub 2020 Jun 4.
The extent to which the gut microbiota may play a role in latitudinal clines of body mass variation (i.e., Bergmann's rule) remains largely unexplored. Here, we collected wild house mice from three latitudinal transects across North and South America and investigated the relationship between variation in the gut microbiota and host body mass by combining field observations and common garden experiments. First, we found that mice in the Americas follow Bergmann's rule, with increasing body mass at higher latitudes. Second, we found that overall differences in the gut microbiota were associated with variation in body mass controlling for the effects of latitude. Then, we identified specific microbial measurements that show repeated associations with body mass in both wild-caught and laboratory-reared mice. Finally, we found that mice from colder environments tend to produce greater amounts of bacteria-driven energy sources (i.e., short-chain fatty acids) without an increase in food consumption. Our findings provide motivation for future faecal transplant experiments directly testing the intriguing possibility that the gut microbiota may contribute to Bergmann's rule, a fundamental pattern in ecology.
肠道微生物组在多大程度上可能在体重变化的纬度梯度（即伯格曼法则）中发挥作用，在很大程度上仍未得到探索。在这里，我们从北美和南美的三条纬度横断线上收集了野生家鼠，并通过结合野外观察和共同花园实验，研究了肠道微生物组与宿主体重变化之间的关系。首先，我们发现美洲的老鼠遵循伯格曼法则，随着纬度的升高，体重逐渐增加。其次，我们发现肠道微生物组的整体差异与体重变化有关，而不受纬度的影响。然后，我们确定了特定的微生物测量值，这些值在野生和实验室饲养的老鼠中都与体重重复相关。最后，我们发现来自较冷环境的老鼠往往会产生更多的细菌驱动的能量来源（即短链脂肪酸），而不会增加食物消耗。我们的研究结果为未来的粪便移植实验提供了动力，直接检验了一个有趣的可能性，即肠道微生物组可能有助于伯格曼法则，这是生态学中的一个基本模式。
