: Popular and non-native probiotics have no overall effect, and do not rescue antibiotic treatment: A longitudinal field study of commercial honey bees.

Probiotics are widely used in agriculture including commercial beekeeping, but there is little empirical evidence supporting their effectiveness. Antibiotic treatments can greatly distort the gut microbiome, reducing its protective abilities and facilitating the growth of antibiotic resistant pathogens. Commercial beekeepers regularly apply antibiotics to combat bacterial infections, often followed by an application of probiotics advertised to ease the impact of antibiotic-induced gut dysbiosis. We tested whether probiotic application affects the gut microbiome or disease prevalence, or rescues the negative effects of antibiotic induced gut dysbiosis. We found no difference in the gut microbiome or disease markers by probiotic application or antibiotic recovery associated with probiotic treatment. A colony-level application of the antibiotics oxytetracycline and tylosin produced an immediate decrease in gut microbiome size, and over the longer-term, very different and persistent dysbiotic effects on the composition and membership of the hindgut microbiome. Our results demonstrate the lack of probiotic effect or antibiotic rescue, detail the duration and character of dysbiotic states resulting from different antibiotics, and highlight the importance of the gut microbiome for honeybee health.

益生菌在农业领域得到广泛应用，包括商业养蜂业，然而，支持其有效性的实证证据却寥寥无几。抗生素治疗会对肠道微生物组造成极大扭曲，降低其保护能力，并促进抗生素耐药病原体的生长。商业养蜂者通常会使用抗生素来对抗细菌感染，随后再应用宣称能缓解抗生素引起的肠道菌群失调影响的益生菌。我们测试了益生菌的应用是否会影响肠道微生物组或疾病流行率，或是否能挽救抗生素诱导的肠道菌群失调的负面影响。我们发现，无论益生菌的应用还是与益生菌治疗相关的抗生素恢复，在肠道微生物组或疾病标志物方面均未观察到差异。在蜂群层面上，氧四环素和泰乐菌素抗生素的应用导致肠道微生物组大小立即下降，从长期来看，对后肠道微生物组的组成和成员产生了非常不同且持久的菌群失调效应。我们的研究结果证明了益生菌效应或抗生素挽救的缺乏，详细描述了不同抗生素引起的菌群失调状态的时间和特征，并强调了肠道微生物组对蜜蜂健康的重要性。