Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
Blue Buffalo Company, Ltd., Wilton, CT 06897, USA.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae274.
Antibiotics are used to treat gastrointestinal diseases or infections but are known to negatively affect stool quality and gut microbiota in cats and dogs. Therefore, identifying dietary strategies that may aid in antibiotic recovery is of interest. The objective of this study was to determine how a veterinary gastrointestinal diet affected the fecal characteristics, microbiota, and metabolite and bile acid (BA) concentrations of cats recovering from metronidazole administration. Twenty-four healthy adult cats were used in an 8-wk completely randomized design study. During a 2-wk baseline, all cats consumed a leading grocery brand diet (GBD). Over the next 2 wk, cats consumed GBD and received metronidazole (20 mg/kg body weight twice daily). At week 4, cats were randomly allotted to one of 2 treatments [GBD; BLUE Natural Veterinary Diet GI Gastrointestinal Support (BB)] and fed for 4 wk. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter (DM) %, metabolites, and microbiota. Microbiota was analyzed by 16S rRNA gene sequencing and qPCR, which was used to calculate dysbiosis index. Data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of diet, time and diet*time. Metronidazole had dramatic effects on all outcomes, including increased fecal scores (looser stools), reduced fecal pH and DM%, reduced fecal short-chain fatty acid, branched-chain fatty acid, ammonia, phenol, and indole concentrations, and altered fecal BA concentrations (increased primary BA; reduced secondary BA). Metronidazole reduced fecal bacterial alpha diversity, increased dysbiosis index, and altered the relative abundance of 78 bacterial genera. Fecal outcomes partially recovered over the next 4 wk, with some being impacted by diet. Fecal acetate concentrations were higher after metronidazole in cats fed BB. Dysbiosis index and alpha diversity measures slowly recovered over 4 wk, without diet differences. Recovery of 16 bacterial genera was impacted by diet. Fecal BA profiles demonstrated a prolonged impairment of primary to secondary BA conversion, with cholic acid being lower after metronidazole in cats fed BB. In conclusion, our data demonstrate that metronidazole is a powerful antibiotic that has long-lasting effects on the fecal microbiota and metabolites of cats. Outcome variables slowly recovered over time, but a gastrointestinal diet may aid in recovery.
抗生素用于治疗胃肠道疾病或感染，但已知会对猫和狗的粪便质量和肠道微生物群产生负面影响。因此，确定可能有助于抗生素恢复的饮食策略是很有意义的。本研究的目的是确定兽医胃肠道饮食如何影响甲硝唑给药后恢复的猫的粪便特征、微生物群、代谢物和胆汁酸 (BA) 浓度。24 只健康成年猫被用于 8 周完全随机设计研究。在 2 周的基线期内，所有猫都食用一种领先的杂货店品牌饮食 (GBD)。在接下来的 2 周内，猫食用 GBD 并接受甲硝唑（20mg/kg 体重，每日 2 次）。在第 4 周，猫被随机分配到 2 种治疗方法之一[GBD；BLUE Natural Veterinary Diet GI 胃肠道支持 (BB)]，并喂养 4 周。每天记录粪便评分，并在第 2、4、5、6、7 和 8 周采集新鲜粪便样本，用于测量 pH 值、干物质 (DM) %、代谢物和微生物群。通过 16S rRNA 基因测序和 qPCR 分析微生物群，并用 qPCR 计算肠道失调指数。使用 SAS 9.4 的混合模型程序分析数据，测试饮食、时间和饮食*时间的影响。甲硝唑对所有结果都有显著影响，包括粪便评分增加（粪便更松散）、粪便 pH 值和 DM%降低、粪便短链脂肪酸、支链脂肪酸、氨、苯酚和吲哚浓度降低以及粪便 BA 浓度改变（初级 BA 增加；二级 BA 减少）。甲硝唑降低了粪便细菌的 alpha 多样性，增加了肠道失调指数，并改变了 78 个细菌属的相对丰度。在接下来的 4 周内，粪便结果部分恢复，其中一些受饮食影响。在 BB 喂养的猫中，甲硝唑后粪便乙酸盐浓度更高。在 4 周内，肠道失调指数和 alpha 多样性指标缓慢恢复，没有饮食差异。16 个细菌属的恢复受到饮食的影响。粪便 BA 谱显示初级到次级 BA 转化的长期损害，在 BB 喂养的猫中，甲硝唑后胆酸水平降低。总之，我们的数据表明，甲硝唑是一种强大的抗生素，对猫的粪便微生物群和代谢物有持久的影响。随着时间的推移，结果变量缓慢恢复，但胃肠道饮食可能有助于恢复。
