School of Biological, Earth and Environmental Sciences, Distillery Fields, University College Cork, Cork T23 TK30, Ireland.
APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
Proc Natl Acad Sci U S A. 2024 Oct 22;121(43):e2402352121. doi: 10.1073/pnas.2402352121. Epub 2024 Oct 14.
Empirical studies from laboratory systems and humans show that the gut microbiota is linked to host health. Similar evidence for effects on traits linked to fitness in nature is rare, not least because experimentally manipulating the gut microbiota is challenging. We isolated, characterized, and cultured a bacterial strain, APC4233, directly from a wild bird (the great tit ) and provided it as a self-administered dietary supplement. We assessed the impact of the treatment on the host microbiota community, on weight, and tested whether the treatment affected a previous result linking microbiota alpha diversity to weight in nestlings. The treatment dramatically increased abundance in the gut microbiota and increased alpha diversity. This effect was strongest in the youngest birds, validating earlier findings pointing to a brief developmental window when the gut microbiota are most sensitive. In time-lagged models, nestling weight was higher in the treatment birds suggesting may have probiotic potential. There was also a positive time-lagged relationship between diversity and weight in control birds but not in the treatment birds, suggesting helped birds compensate for low alpha diversity. We discuss why ecological context is likely key when predicting impacts of the microbiome. The manipulation of the gut microbiota with a host native strain in this wild population provides direct evidence for the role of the microbiota in the ecology and evolution of natural populations.
从实验室系统和人类中获得的实证研究表明，肠道微生物群与宿主健康有关。在自然界中，类似的关于与适应度相关特征的影响的证据很少，这主要是因为实验性地操纵肠道微生物群具有挑战性。我们直接从一种野生鸟类（大山雀）中分离、鉴定和培养了一种细菌菌株 APC4233，并将其作为一种自我管理的饮食补充剂提供。我们评估了该处理对宿主微生物群落、体重的影响，并测试了该处理是否会影响先前将微生物群 alpha 多样性与巢雏体重联系起来的结果。该处理显著增加了肠道微生物群的丰度并增加了 alpha 多样性。这种影响在最年轻的鸟类中最强，验证了早期的发现，即肠道微生物群在发育早期最为敏感。在时间滞后模型中，处理组的巢雏体重较高，表明可能具有益生菌潜力。在对照组中，多样性和体重之间存在正的时间滞后关系，但在处理组中没有，这表明有助于鸟类弥补 alpha 多样性低的问题。我们讨论了为什么在预测微生物组的影响时，生态背景可能是关键。在这个野生种群中，用宿主原生菌株对肠道微生物群进行操纵，为微生物群在自然种群的生态学和进化中的作用提供了直接证据。
