This study aims to investigate the effects of dietary gamma-aminobutyric acid (GABA) supplementation on the growth performance, intestinal immunity, intestinal GABAergic system, amino acid profiles and gut microflora of the weaned piglets. Totally sixteen healthy piglets were randomly assigned into two groups to be fed with the basal diet (Con group) or the basal diet with GABA (20 mg kg⁻¹) supplementation. Body weights and feed intakes were monitored weekly. Piglets were sacrificed after 3 weeks of GABA supplementation to collect the blood, ileum, ileal mucosa and luminal content. Immune-associated factors, GABAergic system, amino acid profiles, and microbiota in the ileum and serum amino acid profiles were explored. The results showed that GABA supplementation improved the growth performance and modulated the intestinal immunity with inhibiting the gene expressions of IL-22, proinflammatory cytokines (IL-1 and IL-18), and Muc1, but promoted the expressions of anti-inflammatory cytokines (IFN-γ, IL-4, and IL-10), TLR6 and MyD88. GABA regulated a few components of the intestinal GABAergic system, increased the levels of most amino acids in the ileal mucosa but reduced the serum amino acid profiles. GABA regulated the population and diversity of intestinal microbiota, such as the abundances of the dominant microbial populations, the community richness, and diversity of the ileal microbiota. In conclusion, GABA supplementation modulated the intestinal functions, including intestinal immunity, intestinal amino acid profiles and gut microbiota, and the results can be helpful for understanding the functions of GABA in the intestine.

中文翻译：

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日粮γ-氨基丁酸补充对断奶仔猪肠道功能的影响†

本研究旨在探讨日粮γ-氨基丁酸（GABA）对断奶仔猪生长性能，肠道免疫力，肠道GABA能系统，氨基酸谱和肠道菌群的影响。将总共​​十六只健康仔猪随机分为两组，分别接受基础饮食（对照组）或GABA基础饮食（20 mg kg ^-1））补充。每周监测体重和采食量。补充GABA 3周后，处死仔猪以收集血液，回肠，回肠粘膜和管腔内容物。探索了免疫相关因子，GABA能系统，氨基酸谱以及回肠中的微生物群和血清氨基酸谱。结果表明，补充GABA可以抑制IL-22，促炎细胞因子（IL-1和IL-18）和Muc1的基因表达，从而改善生长性能并调节肠道免疫力，但可以促进抗炎细胞因子的表达（ IFN-γ，IL-4和IL-10），TLR6和MyD88。GABA调节肠GABA能系统的一些成分，增加了回肠粘膜中大多数氨基酸的水平，但降低了血清氨基酸谱。GABA调节肠道菌群的数量和多样性，例如优势菌群的丰富度，群落丰富度和回肠菌群的多样性。综上所述，补充GABA可以调节肠道功能，包括肠道免疫力，肠道氨基酸谱和肠道菌群，其结果有助于了解GABA在肠道中的功能。