De La Guardia-Hidrogo Vanessa M, Oba Patricia M, Swanson Olivia R, Bauer Laura L, Vinay Elena, Menton John F, Millette Mathieu, Kelly Melissa R, Dilger Ryan N, Swanson Kelly S
Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
Kerry Group, Beloit, WI 53511, USA.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf179.
Acacia fiber is a soluble fiber often used as a processing aid in pet foods. The objective of this experiment was to evaluate the fermentation characteristics of acacia fiber, inulin, pectin (positive control), and cellulose (negative control) using an in vitro fermentation system and feline fecal inoculum. Triplicate samples of each fiber were fermented for 0, 6, 12, and 18 h, with short-chain fatty acids (SCFA), pH, and microbiota measured at each time point. Blank-corrected data were analyzed using PROC GLIMMIX of SAS, with significance set at P ≤ 0.05. Significant (P < 0.01) fiber × time interactions were observed for pH change, gas and SCFA production, and microbiota populations. Pectin and inulin had greater (P < 0.01) gas production than acacia fiber and cellulose. Inulin had the greatest pH reduction, followed by pectin, both of which had greater pH reductions (P < 0.01) than acacia fiber and cellulose. Acacia fiber had a small reduction in pH, being lower than cellulose after 12 h. Total SCFA production, including acetate, propionate, and butyrate, was higher (P < 0.01) in pectin and inulin than acacia fiber and cellulose. However, acacia fiber had greater (P < 0.01) total SCFA, acetate, and propionate production than cellulose after 12 h. Bacterial alpha diversity metrics increased (P < 0.01) during acacia fiber fermentation and decreased (P < 0.01) during inulin and pectin fermentation. Bacterial beta diversity shifted over time and showed separate clustering of bacterial communities among the different fiber substrates evaluated. The relative abundances of predominant (% sequences > 1%) bacterial genera were affected by significant fiber × time interactions. Specifically, acacia fiber had a greater (P < 0.01) increase in Bacteroides, Blautia, and Faecalibacterium than other fibers. Inulin had a greater (P < 0.01) increase in Collinsella, Prevotella, Megamonas, Holdemanella, Blautia, and Faecalibacterium, whereas pectin had a greater (P < 0.01) increase in Bifidobacterium, Lactobacillus, Phascolarctobacterium, and Succinivibrio. These results suggest that acacia fiber is moderately fermentable, resulting in low gas and SCFA production, greater bacterial diversity, and microbiota shifts. Although positive responses were observed in vitro, research in live animals is necessary to confirm potential benefits in felines.
阿拉伯胶纤维是一种可溶性纤维，常用于宠物食品中作为加工助剂。本实验的目的是使用体外发酵系统和猫粪便接种物，评估阿拉伯胶纤维、菊粉、果胶（阳性对照）和纤维素（阴性对照）的发酵特性。每种纤维的三份重复样品分别发酵0、6、12和18小时，在每个时间点测量短链脂肪酸（SCFA）、pH值和微生物群。使用SAS的PROC GLIMMIX对空白校正后的数据进行分析，显著性设定为P≤0.05。在pH值变化、气体和SCFA产生以及微生物群数量方面，观察到显著的（P<0.01）纤维×时间相互作用。果胶和菊粉的产气率高于（P<0.01）阿拉伯胶纤维和纤维素。菊粉的pH值降低幅度最大，其次是果胶，两者的pH值降低幅度均大于（P<0.01）阿拉伯胶纤维和纤维素。阿拉伯胶纤维的pH值有小幅降低，12小时后低于纤维素。包括乙酸盐、丙酸盐和丁酸盐在内的总SCFA产量，果胶和菊粉高于（P<0.01）阿拉伯胶纤维和纤维素。然而，12小时后，阿拉伯胶纤维的总SCFA、乙酸盐和丙酸盐产量高于（P<0.01）纤维素。在阿拉伯胶纤维发酵过程中，细菌α多样性指标增加（P<0.01），而在菊粉和果胶发酵过程中降低（P<0.01）。细菌β多样性随时间变化，在所评估的不同纤维底物之间显示出细菌群落的单独聚类。主要细菌属（%序列>1%）的相对丰度受到显著的纤维×时间相互作用的影响。具体而言，阿拉伯胶纤维中拟杆菌属、布劳特氏菌属和粪杆菌属的增加幅度大于（P<0.01）其他纤维。菊粉中柯林斯菌属、普雷沃菌属、巨单胞菌属、霍尔德曼菌属、布劳特氏菌属和粪杆菌属的增加幅度更大（P<0.01），而果胶中双歧杆菌属、乳酸杆菌属、考拉杆菌属和琥珀酸弧菌属的增加幅度更大（P<0.01）。这些结果表明，阿拉伯胶纤维具有适度的可发酵性，导致气体和SCFA产量较低、细菌多样性增加以及微生物群变化。尽管在体外观察到了积极反应，但仍需要在活体动物中进行研究，以确认对猫的潜在益处。
