Table_1_Absence of Gut Microbiota Reduces Emotional Reactivity in Japanese Quails (Coturnix japonica).docx

Background: Recent studies have demonstrated an effect of the gut microbiota on brain development and behavior leading to the concept of the microbiota-gut-brain axis. However, its effect on behavior in birds is unknown. The aim of the present study was to determine the effect of the absence of gut microbiota on emotional reactivity in birds by comparing germ-free (GF) quails to those colonized (COL) with gut microbiota.Material and Methods: From hatching, the quails of both groups GF (n = 36) and COL (n = 36) were reared in sterile isolators. The COL quails were colonized at day 2 by introducing a pool of droppings from conventional adult females into the drinking water and feed. The quails were weighed individually on day 2, 6, and 14. From day 8, emotional reactivity was assessed in each group in the isolators through several behavioral tests.Results: GF quails showed a considerable decrease in emotional reactivity demonstrated by spending less time in tonic immobility during the tonic immobility test (242 s ± 31 vs. 331 s ± 32, p ≤ 0.05), traveling a shorter distance (3,897 cm ± 242 vs. 4,827 cm ± 278, p ≤ 0.05) at a lower velocity (6.55 cm/s ± 0.4 vs. 8.1 cm/s ± 0.5, p ≤ 0.05) during the social separation test and spending more time near an object at the beginning of the novel object test (33.7 s ± 6.4 vs. 18.5 s ± 4.1, p ≤ 0.05). No difference in growth was found between the 2 groups.Conclusion: For the first time, this study demonstrates that the absence of gut microbiota reduces emotional reactivity in Japanese quails in situations of fear and social perturbation without influence on growth.

背景：近期研究业已证实肠道微生物群对大脑发育及行为的影响，进而引出了微生物群-肠道-大脑轴的概念。然而，其对鸟类行为的影响尚不明确。本研究的目的是通过比较无微生物群（GF）鹌鹑与肠道微生物群定植（COL）鹌鹑在情绪反应上的差异，以确定肠道微生物群缺失对鸟类情绪反应的影响。材料与方法：从孵化之日起，GF组（n = 36）和COL组（n = 36）的鹌鹑均在无菌隔离器中饲养。COL组的鹌鹑在2日龄时通过引入来自常规成年雌性鹌鹑的粪便混合物至饮水和饲料中实现定植。鹌鹑在2日龄、6日龄和14日龄时分别进行称重。从8日龄开始，通过一系列行为测试对隔离器中的每组的情绪反应进行评估。结果：GF组鹌鹑在紧张性僵直测试中表现出显著的情绪反应降低，表现为在紧张性僵直测试中花费的时间减少（242秒±31秒 vs. 331秒±32秒，p ≤ 0.05），在社交分离测试中移动的距离缩短（3,897厘米±242厘米 vs. 4,827厘米±278厘米，p ≤ 0.05），速度降低（6.55厘米/秒±0.4厘米/秒 vs. 8.1厘米/秒±0.5厘米/秒，p ≤ 0.05），以及在新颖物体测试开始时靠近物体的时间增加（33.7秒±6.4秒 vs. 18.5秒±4.1秒，p ≤ 0.05）。两组间的生长情况没有发现差异。结论：本研究首次证实，肠道微生物群的缺失会降低日本鹌鹑在恐惧和社交干扰情境下的情绪反应，而对生长无影响。