Fruit pomaces are by-products rich in polyphenol compounds and dietary fiber. They seem to play an important role in regulating the gut microbiota, morphology and physiology. The aim of this study was to assess whether apple (A), blackurrant (B) or strawberry (S) pomaces could be suitable ingredients in broiler diets and their effect on gut health. A total of 480 male broilers were randomly allotted to 8 dietary treatments with lower (3%-L) or higher (6%-H) dietary fiber content: two control groups (CL/CH), two A diets (AL/AH), two B diets (BL/BH), two S diets (SL/SH). Diet and fruit pomaces were chemically analyzed to assess polyphenol concentration and fibre fraction content. After the evaluation of growth performance, 6 birds/group were slaughtered at 35 days of age. Morphometric and histopathological investigations were performed on duodenum, jejunum and ileum. Excreta were collected to perform microbiota evaluation by 16S DNA sequencing. Weight, viscosity, enzymatic activity, short chain fatty acid (SCFAs) and ammonia concentration were determined in ileum and/or ceca content. A pomace and A diets showed the lowest polyphenol content and the highest content of soluble fibre fraction. No significant differences were observed for growth performance, gut morphometry and histopathology (P > 0.05). Dietary fruit pomace inclusion increased the weight of ileum and ceca and the ileum digesta viscosity (P < 0.05). In the ileum, A and S groups showed lower bacterial α-glucosidase activity than C groups. Moreover, small intestine SCFAs concentration was higher in fruit pomaces diets (P < 0.05). In ceca, B and S groups showed lower ammonia concentration and higher SCFAs than C. Dietary treatments also influenced the activity of α-glucosidase, α-galactosidase, β-galactosidase β-glucuronidase and xylase. Regarding microbiota, at phylum level, Firmicutes were differentially abundant across treatment (maximum for C and minimum in S, FDR > 0.05). At genus level, an increase of Weissella in AH and Erwinia in S/B diets, as well as a decrease of Lactobacillus in all fruit pomace groups were recorded (P < 0.05). Fruit pomaces could be suitable ingredients in poultry nutrition even if further studies are needed to better understand which doses is more recommended to avoid negative effects on gut microbiota.

中文翻译：

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家禽日粮中加入干果渣：生长性能、肠道形态和生理。

果渣是富含多酚化合物和膳食纤维的副产品。它们似乎在调节肠道微生物群、形态和生理方面发挥着重要作用。本研究的目的是评估苹果 (A)、黑莓 (B) 或草莓 (S) 果渣是否可以成为肉鸡日粮中的合适成分及其对肠道健康的影响。总共 480 头雄性肉鸡被随机分配到 8 个膳食纤维含量较低 (3%-L) 或较高 (6%-H) 的日粮处理组：两个对照组 (CL/CH)，两个 A 日粮 (AL/AH) ，两种 B 饮食 (BL/BH)，两种 S 饮食 (SL/SH)。对饮食和果渣进行化学分析，以评估多酚浓度和纤维组分含量。生长性能评价后，35日龄屠宰6只鸡/组。对十二指肠进行形态学和组织病理学研究，空肠和回肠。收集排泄物通过 16S DNA 测序进行微生物群评估。在回肠和/或盲肠内容物中测定重量、粘度、酶活性、短链脂肪酸 (SCFA) 和氨浓度。A 渣和 A 日粮的多酚含量最低，可溶性纤维部分的含量最高。生长性能、肠道形态学和组织病理学未观察到显着差异（P > 0.05）。日粮果渣添加增加了回肠和盲肠的重量以及回肠食糜的粘度（P < 0.05）。在回肠中，A 组和 S 组的细菌 α-葡萄糖苷酶活性低于 C 组。此外，果渣日粮中小肠 SCFAs 浓度较高（P < 0.05）。在盲肠中，B 组和 S 组显示出比 C 组更低的氨浓度和更高的 SCFAs。饮食处理也影响α-葡萄糖苷酶、α-半乳糖苷酶、β-半乳糖苷酶、β-葡萄糖醛酸酶和木糖酶的活性。关于微生物群，在门水平上，厚壁菌门在不同处理中的丰度差异很大（C 最大，S 最小，FDR > 0.05）。在属水平上，所有果渣组中AH和欧文氏菌的Weissella增加，而Lactobacillus的减少（P < 0.05）。即使需要进一步研究以更好地了解更推荐哪种剂量以避免对肠道微生物群的负面影响，果渣仍可能是家禽营养中的合适成分。不同处理的厚壁菌门差异丰富（C 最大，S 最小，FDR > 0.05）。在属水平上，所有果渣组中AH和欧文氏菌的Weissella增加，而Lactobacillus的减少（P < 0.05）。即使需要进一步研究以更好地了解更推荐哪种剂量以避免对肠道微生物群的负面影响，果渣仍可能是家禽营养中的合适成分。不同处理的厚壁菌门差异丰富（C 最大，S 最小，FDR > 0.05）。在属水平上，所有果渣组中AH和欧文氏菌的Weissella增加，而Lactobacillus的减少（P < 0.05）。即使需要进一步研究以更好地了解更推荐哪种剂量以避免对肠道微生物群的负面影响，果渣仍可能是家禽营养中的合适成分。