Effects of Dietary GABA Levels on Growth, Muscle Quality, and Liver Lipid Profile: Insights from Lipidomics in Juvenile Yellowfin Seabream Acanthopagrus latus

Gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter, is used as a feed additive in aquaculture. However, its effects on muscle quality and lipid metabolism in fish remain understudied. Therefore, three diets supplemented with 0%, 0.01%, and 0.10% GABA were fed to juvenile Acanthopagrus latus (initial weight: 9.96 g) for 9 weeks, followed by analyses of growth performance, muscle quality indices, and hepatic lipid profiles. Fish fed 0.01% GABA showed the highest weight gain rate (p < 0.05). Their muscles exhibited improved muscle texture, higher levels of essential/non-essential and flavor amino acids, and a higher proportion of long-chain polyunsaturated fatty acids (LC-PUFAs), including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), along with triglycerides and cardiolipin enriched in LC-PUFA chains (p < 0.05). Moreover, their livers demonstrated increased levels of triglycerides, phosphatidylethanolamine, and LC-PUFA, along with reduced levels of phosphatidylcholine, lysophosphatidylcholine, lysophosphatidylethanolamine, and phosphatidylserine (p < 0.05). These results suggest that 0.01% GABA supplementation improves growth performance, enhances flesh quality, and optimizes liver lipid profiles in A. latus.