The housefly (Musca domestica) is a common insect species with only a few recurrent bacterial taxa in its gut microbiota, because the numerous microbial acquisition routes in its septic habitats can favor transient microbes. Here, we investigated the role of the diet on the microbiota and the developmental success of a housefly strain reared on three substrates. We used a control wheat bran-based substrate, and added clotted cream and sucrose to make a high-fat, and a high-sugar substrate, respectively. The conducted survey revealed that, in contrast to the high-fat diet, the high-sugar diet caused lower developmental success and less diverse microbiota, in which several lactobacilli were replaced with Weissella bacterial phylotypes. Cultures with sucrose as the sole carbon source confirmed that a Weissela confusa strain, isolated from larvae, could utilize sucrose more efficiently than other tested lactic acid bacteria; a result also supported by gene function prediction analysis. Enhancing the rearing substrate with Limosilactobacillus fermentum and Lactiplantibacillus plantarum strains, which were isolated from control larvae, could not only revert the negative effect of the high-sucrose diet on development, but also increase the gut bacterial diversity. In our study, we show that the microbiota shifts in response to the high-sucrose diet did not benefit the host, that showed lower developmental success. In contrast, high-sucrose favored specific components of the microbiota, that continued to be enriched even after multiple generations, outcompeting beneficial bacteria. Also, microbiome manipulation showed the potential of probiotics to rescue host performance and restore the microbiome.

中文翻译：

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高糖饮食导致家蝇幼虫肠道中有益益生菌的流失


家蝇 （Musca domestica） 是一种常见的昆虫物种，其肠道微生物群中只有少数反复出现的细菌类群，因为其化粪池栖息地中的众多微生物获取途径可能有利于瞬时微生物。在这里，我们研究了饮食对微生物群的作用以及在三种基质上饲养的家蝇菌株的发育成功。我们使用了基于对照麦麸的底物，并添加了凝结的奶油和蔗糖，分别制成高脂肪和高糖底物。进行的调查显示，与高脂肪饮食相比，高糖饮食导致较低的发育成功率和较少的微生物群多样性，其中几种乳酸杆菌被魏斯氏菌系统型取代。以蔗糖作为唯一碳源的培养物证实，从幼虫中分离的 Weissela confusa 菌株比其他测试的乳酸菌更有效地利用蔗糖;基因功能预测分析也支持这一结果。用从对照幼虫中分离的发酵乳乳杆菌和植物乳植杆菌菌株增强饲养基质，不仅可以逆转高蔗糖饮食对发育的负面影响，还可以增加肠道细菌的多样性。在我们的研究中，我们表明响应高蔗糖饮食的微生物群变化对宿主没有好处，这表明发育成功率较低。相比之下，高蔗糖偏爱微生物群的特定成分，即使在多代之后，这些成分仍继续富集，胜过有益细菌。此外，微生物组操作显示了益生菌挽救宿主性能和恢复微生物组的潜力。