It is increasingly recognized that gut microbiota have a major effect on the physiology, biology, ecology and evolution of their animal hosts. Because in social insects, the gut microbiota is acquired through the diet and by contact with nest provisions, it can be hypothesized that regular supplementation of microorganisms to the diet will have an impact on the fitness of the consumer and on the development of the whole colony. To test this hypothesis, we investigated how supplementation of bacteria, yeasts, and combinations of the two to either pollen or nectar affected colony development in the social bumblebee Bombus terrestris. Three yeasts and three bacterial species that live at the flower-insect interface were used in the experiments and the development of bumblebee colonies was monitored over a period of 10 weeks. The results showed that administration of microbes via pollen had a stronger positive impact on colony development than when provided via sugar water. Supplementation of bacteria led, in general, to a faster egg laying, higher brood size and increased production of workers during the first weeks, whereas yeasts or a combination of yeasts and bacteria had less impact on colony development. However, the results differed between microbial species, with Wickerhamiella bombiphila and Rosenbergiella nectarea showing the strongest increase in colony development. Torulaspora delbrueckii induced early male production, which is likely a fitness cost. We conclude that the tested bacteria-yeast consortia did not result in better colony development than the interacting species alone.

人们越来越认识到，肠道菌群对其动物宿主的生理，生物学，生态学和进化有重大影响。因为在社交昆虫中，肠道微生物群是通过饮食获得的，并且是通过与巢穴食物接触而获得的，因此可以假设定期向饮食中补充微生物会影响消费者的健康状况以及整个菌落的发育。为了验证这一假设，我们调查了在花粉或花蜜中添加细菌，酵母以及两者的组合如何影响社交大黄蜂熊蜂的菌落发育。。实验中使用了生活在花-昆虫界面的三种酵母和三种细菌，并在10周的时间内监测了大黄蜂菌落的发育。结果表明，与通过糖水提供微生物相比，通过花粉施用微生物对菌落发育具有更强的积极影响。通常，补充细菌会导致产卵更快，产蛋量更高以及头几周工人的产量增加，而酵母或酵母与细菌的结合对菌落发育的影响较小。但是，结果在微生物物种之间有所不同，其中威克汉姆杆菌和罗森伯格菌的花蜜表现出最强的菌落发育。ul导致男性早期生产，这很可能是健身成本。我们得出的结论是，经过测试的细菌-酵母菌联合体没有比单独的相互作用物种更好的菌落发育。