{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T05:07:16Z","timestamp":1789103236587,"version":"build-2803163510"},"reference-count":37,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T00:00:00Z","timestamp":1789084800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Physiol."],"abstract":"<jats:p>\n                    This study evaluated the individual and combined effects of citric acid and oregano essential oil on growth performance, digestive capacity, immune responses, and disease resistance against\n                    <jats:italic>Nocardia seriolae<\/jats:italic>\n                    in spotted sea bass (\n                    <jats:italic>Lateolabrax maculatus<\/jats:italic>\n                    ) fed a high soybean meal (SBM) diet. Five isonitrogenous and isolipidic diets were formulated: a positive control diet (LS, 0% soybean meal), a negative control diet (HS, 30% soybean meal), and three supplemented diets based on HS, including 1% citric acid (HSC), 0.3% oregano essential oil (HSO), and their combination (HSCO). Fish (initial weight around 68\u00a0ag) were fed for 8 weeks, followed by a 20-day\n                    <jats:italic>N. seriolae<\/jats:italic>\n                    challenge trial. Results showed that compared with the LS group, fish fed with the HS diet significantly reduced weight gain and lipase activity, while upregulating the mRNA expression of pro-inflammatory cytokines in the mid-intestine. On the contrary, supplementation with oregano essential oil, alone or in combination with citric acid, significantly improved growth performance, whereas citric acid alone exerted no significant improvement on growth. Nevertheless, all three additive groups effectively enhanced lipase activity and suppressed the transcription of intestinal pro-inflammatory genes compared to the HS group. Notably, the HSCO group exhibited significantly higher C3 and C4 levels than both HSC and HSO groups, indicating a superior combined effect on complement activation, and achieved a survival rate (55%) after\n                    <jats:italic>N. seriolae<\/jats:italic>\n                    challenge relative to the HS group (20%), which was close to that of the LS group (65%). Overall, dietary supplementation with 1% citric acid and 0.3% oregano essential oil effectively mitigated the adverse impacts in\n                    <jats:italic>L. maculatus<\/jats:italic>\n                    fed with high soybean meal diets.\n                  <\/jats:p>","DOI":"10.3389\/fphys.2026.1921084","type":"journal-article","created":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T04:31:59Z","timestamp":1789101119000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Combined supplementation of citric acid and oregano essential oil enhanced growth performance, digestion, immunity, and resistance against Nocardia seriolae in spotted sea bass (Lateolabrax maculatus) fed high soybean meal diet"],"prefix":"10.3389","volume":"17","author":[{"given":"Haohang","family":"Fang","sequence":"first","affiliation":[{"name":"Key Laboratory of Microecological Resources and Utilization in Breeding Industry, Ministry of Agriculture and Rural Affairs, Guangdong Haid Group Co., Ltd.","place":["Guangzhou, Guangdong, China"]},{"name":"Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Institute of Hydrobiology, Chinese Academy of Sciences","place":["Wuhan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hanle","family":"Zhang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Microecological Resources and Utilization in Breeding Industry, Ministry of Agriculture and Rural Affairs, Guangdong Haid Group Co., Ltd.","place":["Guangzhou, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianxue","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Microecological Resources and Utilization in Breeding Industry, Ministry of Agriculture and Rural Affairs, Guangdong Haid Group Co., Ltd.","place":["Guangzhou, Guangdong, China"]},{"name":"Zhuhai Rongchuan Feed Co., Ltd.","place":["Zhuhai, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lei","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Microecological Resources and Utilization in Breeding Industry, Ministry of Agriculture and Rural Affairs, Guangdong Haid Group Co., Ltd.","place":["Guangzhou, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Biao","family":"Yun","sequence":"additional","affiliation":[{"name":"Key Laboratory of Microecological Resources and Utilization in Breeding Industry, Ministry of Agriculture and Rural Affairs, Guangdong Haid Group Co., Ltd.","place":["Guangzhou, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xueqiao","family":"Qian","sequence":"additional","affiliation":[{"name":"Key Laboratory of Microecological Resources and Utilization in Breeding Industry, Ministry of Agriculture and Rural Affairs, Guangdong Haid Group Co., Ltd.","place":["Guangzhou, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shouqi","family":"Xie","sequence":"additional","affiliation":[{"name":"Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Institute of Hydrobiology, Chinese Academy of Sciences","place":["Wuhan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,11]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.fsi.2020.05.056","article-title":"Dietary origanum essential oil improved antioxidative status, immune-related genes, and resistance of common carp (Cyprinus carpio L.) to Aeromonas hydrophila infection","volume":"104","author":"Abdel-Latif","year":"2020","journal-title":"Fish. 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