Table_10_Fecal microbiota composition, serum metabolomics, and markers of inflammation in dogs fed a raw meat-based diet compared to those on a kibble diet.XLSX

IntroductionDespite the potential health risks associated with feeding raw and non-traditional diets, the use of these diets in dogs is increasing, yet the health outcomes associated with these diets is not well understood. This study investigates the effect of feeding dogs a kibble or raw meat-based diets on fecal microbiota composition, serum metabolomics and inflammatory markers.
MethodsClinically healthy dogs with a history of consuming either kibble (KD, n = 27) or raw meat-based diets (RMBD, n = 28) for more than 1 year were enrolled. Dogs were fed a standardized diet of either a single brand of KD or RMBD for 28 days. Serum and fecal samples were collected for analysis of microbiota, metabolomics, and inflammatory markers. Multiple regression analysis was performed for each of the metabolites and inflammatory markers, with feed group, age and BCS included as independent variables.
ResultsThe fecal microbiota composition differed between the KD and RMBD groups. Beta-diversity and some indices of alpha-diversity (i.e., Shannon and Simpson) were different between the two diet groups. Sixty- three serum metabolites differed between KD and RMBD-fed dogs with the majority reflecting the differences in macronutrient composition of the two diets.
Fecal IAP, IgG and IgA were significantly higher in RMBD dogs compared to KD dogs, while systemic markers of inflammation, including serum c-reactive protein (CRP), galectin, secretory receptor of advanced glycation end-products (sRAGE), haptoglobin, and serum IgG were similar in dogs fed either diet.
DiscussionDiet composition significantly affected fecal microbiota composition and metabolome. Although it had a potentially beneficial effect on local inflammatory markers, feeding RMBD had no impact on systemic inflammation. The influence of these changes on long term health outcomes provides an area for future study.

引言 尽管生肉及非传统犬粮存在潜在健康风险，但这类日粮在宠物犬中的饲喂应用正持续增长，然而其对应的健康结局目前仍未得到充分阐明。本研究旨在探究饲喂膨化粮（kibble）与生肉基日粮对犬粪便微生物群组成、血清代谢组及炎症标志物的影响。
方法 本研究纳入了既往饲喂史达1年以上的临床健康犬，其中27只饲喂膨化粮（kibble diet, KD，n=27），28只饲喂生肉基日粮（raw meat-based diet, RMBD，n=28）。所有受试犬随后均接受为期28天的标准化饲喂，分别饲喂单一品牌的KD或RMBD日粮。采集血清与粪便样本，用于微生物群、代谢组及炎症标志物的检测分析。针对所有代谢物与炎症标志物，本研究以饲喂组别、年龄及体况评分（Body Condition Score, BCS）作为自变量，开展多元回归分析。
结果 KD组与RMBD组犬的粪便微生物群组成存在显著差异。两组的β多样性（beta-diversity）及部分α多样性（alpha-diversity）指数（如香农指数（Shannon）与辛普森指数（Simpson））均存在显著差异。KD组与RMBD组犬共有63种血清代谢物存在差异，其中大部分差异与两种日粮的宏量营养素组成差异相关。
RMBD组犬的粪便IAP、免疫球蛋白G（IgG）及免疫球蛋白A（IgA）水平均显著高于KD组；而两组犬的系统性炎症标志物，包括血清C反应蛋白（C-reactive protein, CRP）、半乳糖凝集素（galectin）、晚期糖基化终产物分泌型受体（secretory receptor of advanced glycation end-products, sRAGE）、结合珠蛋白（haptoglobin）及血清IgG水平均无显著差异。
讨论 日粮组成可显著影响犬的粪便微生物群组成与代谢组。尽管饲喂生肉基日粮对局部炎症标志物可能存在有益影响，但并未对系统性炎症产生显著作用。上述变化对犬长期健康结局的影响，仍有待未来进一步研究探索。