Table3_Examining the effects of Salmonella phage on the caecal microbiota and metabolome features in Salmonella-free broilers.docx

Bacteriophages selectively infect and kill their target bacterial host, being a promising approach to controlling zoonotic bacteria in poultry production. To ensure confidence in its use, fundamental questions of safety and toxicity monitoring of phage therapy should be raised. Due to its high specificity, a minimal impact on the gut ecology is expected; however, more in-depth research into key parameters that influence the success of phage interventions has been needed to reach a consensus on the impact of bacteriophage therapy in the gut. In this context, this study aimed to investigate the interaction of phages with animals; more specifically, we compared the caecum microbiome and metabolome after a Salmonella phage challenge in Salmonella-free broilers, evaluating the role of the phage administration route. To this end, we employed 45 caecum content samples from a previous study where Salmonella phages were administered via drinking water or feed for 24 h from 4, 5 to 6-weeks-old broilers. High-throughput 16S rRNA gene sequencing showed a high level of similarity (beta diversity) but revealed a significant change in alpha diversity between broilers with Salmonella-phage administered in the drinking water and control. Our results showed that the phages affected only a few genera of the microbiota’s structure, regardless of the administration route. Among these, we found a significant increase in Streptococcus and Sellimonas in the drinking water and Lactobacillus, Anaeroplasma and Clostridia_vadinBB60_group in the feed. Nevertheless, the LC-HRMS-based metabolomics analyses revealed that despite few genera were significantly affected, a substantial number of metabolites, especially in the phage administered in the drinking water were significantly altered (64 and 14 in the drinking water and feed groups, respectively). Overall, our study shows that preventive therapy with bacteriophages minimally alters the caecal microbiota but significantly impacts their metabolites, regardless of the route of administration.

噬菌体有选择性地感染并消灭其目标细菌宿主，这为控制家禽生产中的动物源性细菌提供了一种有潜力的方法。为确保其应用的安全性，有必要提出噬菌体治疗的安全性及毒性监测的基本问题。鉴于其高度特异性，预期对肠道生态的影响将微乎其微；然而，为了就噬菌体治疗对肠道影响达成共识，仍需对影响噬菌体干预成功的关键参数进行更深入的研究。在此背景下，本研究旨在探讨噬菌体与动物之间的相互作用；更具体地说，我们比较了无菌鸡在接种沙门氏菌噬菌体后的盲肠微生物组和代谢组，评估了噬菌体给药途径的作用。为此，我们从先前研究中选取了45份盲肠内容物样本，这些样本来自通过饮水或饲料在4至6周龄的鸡中给药沙门氏菌噬菌体的实验，给药持续24小时。高通量16S rRNA基因测序显示，各组之间的beta多样性高度相似，但饮水给药的沙门氏菌噬菌体处理鸡与对照鸡之间的alpha多样性发生了显著变化。我们的结果显示，无论给药途径如何，噬菌体仅影响了微生物群结构中的少数几个属。在这些属中，我们发现饮水给药中链球菌和赛洛菌属显著增加，而乳酸杆菌、厌氧菌和梭菌_vadinBB60_group在饲料中显著增加。尽管如此，基于LC-HRMS的代谢组学分析揭示，尽管受影响的属数量不多，但大量代谢物，尤其是在饮水给药中的噬菌体，发生了显著改变（饮水组和饲料组分别有64和14个）。总的来说，我们的研究表明，噬菌体预防性治疗对盲肠微生物群的影响微乎其微，但对其代谢物的影响则显著，且不受给药途径的影响。