{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T06:05:50Z","timestamp":1790057150457,"version":"4.0.1"},"reference-count":32,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T00:00:00Z","timestamp":1790035200000},"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. Microbiol."],"abstract":"<jats:p>A decline in the antioxidant capacity of the organism is observed in late-laying hens. Protocatechuic acid (PCA), a phenolic compound, possesses antioxidant and anti-inflammatory properties. However, whether dietary supplementation with PCA can alleviate these adverse effects in late-laying hens remains unclear. A total of 576 Hy-Line Brown laying hens aged 500\u202fdays were randomly divided into 4 groups, each with 6 replicates of 24 hens. The four groups consisted of a basal diet group (CK) and three experimental groups supplemented with 0.05, 0.1, and 0.2% PCA (LPCA, MPCA, and HPCA, respectively). The trial lasted 49\u202fdays, including a 1-week adaptation period followed by a 6-week experimental period. Dietary PCA supplementation significantly increased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and decreased the level of malondialdehyde (MDA). Furthermore, PCA supplementation also significantly decreased the levels of inflammatory factors such as tumor necrosis factor-alpha (TNF-\u03b1), interleukin-1 beta (IL-1\u03b2), and interleukin-6 (IL-6). Ileum transcriptomic analyses revealed that the differentially expressed genes were significantly enriched in pathways such as transmembrane transport activity, signal receptor binding, the PPAR signaling pathway, and intestinal immunity. We further sequenced cecal microbiota, showing that the structure of the microbiota has undergone significant changes; beneficial bacterial communities such as g_Bacteroides and g_Odoribacter were significantly enriched in the PCA treatment group. Metabolomic analysis revealed that the differential metabolites were predominantly enriched in pathways closely associated with intestinal digestive and absorptive functions, including tryptophan metabolism, arginine biosynthesis, cysteine and methionine metabolism, and glycerophospholipid metabolism, all of which were found to be activated. Subsequently, non-targeted metabolomic analysis revealed that these differential metabolites were primarily involved in tryptophan metabolism, arginine biosynthesis, cysteine and methionine metabolism, and glycerophospholipid metabolism. Therefore, supplementing PCA in the feed of late-laying hens can improve antioxidant capacity, inflammatory response, and intestinal microbiota composition to enhance intestinal health.<\/jats:p>","DOI":"10.3389\/fmicb.2026.1866286","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T05:40:08Z","timestamp":1790055608000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Dietary supplementation of protocatechuic acid improves antioxidant capacity and intestinal health in late-laying hens"],"prefix":"10.3389","volume":"17","author":[{"given":"Jiahao","family":"Yan","sequence":"first","affiliation":[{"name":"Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences","place":["Hangzhou, China"]},{"name":"Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaiqi","family":"Weng","sequence":"additional","affiliation":[{"name":"College of Animal Science and Technology, Yangzhou University","place":["Yangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Yang","sequence":"additional","affiliation":[{"name":"Wowo Agriculture Co., Ltd","place":["Wenzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tiantian","family":"Gu","sequence":"additional","affiliation":[{"name":"Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences","place":["Hangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tao","family":"Zhang","sequence":"additional","affiliation":[{"name":"Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Huang","sequence":"additional","affiliation":[{"name":"Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences","place":["Hangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,22]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"102021","DOI":"10.1016\/j.psj.2022.102021","article-title":"The relationship among avian influenza, gut microbiota and chicken immunity: an updated overview","author":"Abd El-Hack","year":"2022","journal-title":"Poult. Sci."},{"key":"ref2","doi-asserted-by":"publisher","first-page":"103475","DOI":"10.1016\/j.psj.2024.103475","article-title":"A systematic review of potential productivity, egg quality, and animal welfare implications of extended lay cycles in commercial laying hens in Canada","volume":"103","author":"Arulnathan","year":"2024","journal-title":"Poult. Sci."},{"key":"ref3","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1097\/WOX.0b013e3182439613","article-title":"Oxidative stress and antioxidant defense","volume":"5","author":"Birben","year":"2012","journal-title":"World Allergy Organ J"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1097\/MCO.0b013e3280115d36","article-title":"Emerging aspects of gut sulfur amino acid metabolism","volume":"10","author":"Burrin","year":"2007","journal-title":"Curr. Opin. Clin. Nutr. Metab. Care"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1467","DOI":"10.1096\/fasebj.13.11.1467","article-title":"Selenium-dependent cellular glutathione peroxidase protects mice against a pro-oxidant-induced oxidation of NADPH, NADH, lipids, and protein","volume":"13","author":"Cheng","year":"1999","journal-title":"FASEB J."},{"key":"ref6","doi-asserted-by":"publisher","first-page":"2559","DOI":"10.3390\/ijms18122559","article-title":"Ppar\u03b3 modulates long chain fatty acid processing in the intestinal epithelium","volume":"18","author":"Duszka","year":"2017","journal-title":"Int. J. Mol. Sci."},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1022783","DOI":"10.3389\/fmicb.2022.1022783","article-title":"Early life microbiota transplantation from highly feed-efficient broiler improved weight gain by reshaping the gut microbiota in laying chicken","volume":"13","author":"Elokil","year":"2022","journal-title":"Front. Microbiol."},{"key":"ref8","doi-asserted-by":"publisher","first-page":"1277102","DOI":"10.3389\/fimmu.2023.1277102","article-title":"The role of intestinal microbes on intestinal barrier function and host immunity from a metabolite perspective","volume":"14","author":"Fu","year":"2023","journal-title":"Front. Immunol."},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1016\/j.jia.2025.08.002","article-title":"Systematic changes in intestinal mucosal barrier function and related aspects of laying hens during the aging process","author":"Hou","year":"2025","journal-title":"J. Integr. Agric."},{"key":"ref10","doi-asserted-by":"publisher","first-page":"92","DOI":"10.1186\/s40104-020-00492-9","article-title":"Dietary protocatechuic acid ameliorates inflammation and up-regulates intestinal tight junction proteins by modulating gut microbiota in LPS-challenged piglets","volume":"11","author":"Hu","year":"2020","journal-title":"J. Anim. Sci. Biotechnol."},{"key":"ref11","doi-asserted-by":"publisher","first-page":"2419565","DOI":"10.1080\/19490976.2024.2419565","article-title":"Regulatory mechanism of cysteine-dependent methionine biosynthesis in Bifidobacterium longum: insights into sulfur metabolism in gut microbiota","volume":"16","author":"Kim","year":"2024","journal-title":"Gut Microbes"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"284","DOI":"10.1124\/dmd.114.061614","article-title":"Quantitative transporter proteomics by liquid chromatography with tandem mass spectrometry: addressing methodologic issues of plasma membrane isolation and expression-activity relationship","volume":"43","author":"Kumar","year":"2015","journal-title":"Drug Metab. Dispos."},{"key":"ref13","doi-asserted-by":"publisher","first-page":"1705","DOI":"10.3390\/biology14121705","article-title":"Dietary polyphenols-gut microbiota interactions: intervention strategies and metabolic regulation for intestinal diseases","volume":"14","author":"Li","year":"2025","journal-title":"Biology (Basel)"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"815","DOI":"10.3390\/microorganisms13040815","article-title":"Odoribacter splanchnicus-a next-generation probiotic candidate","volume":"13","author":"Li","year":"2025","journal-title":"Microorganisms"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"192","DOI":"10.1016\/s0955-2863(00)00064-4","article-title":"Effects of phospholipids on sphingomyelin hydrolysis induced by intestinal alkaline sphingomyelinase: an in vitro study","volume":"11","author":"Liu","year":"2000","journal-title":"J. Nutr. Biochem."},{"key":"ref16","doi-asserted-by":"publisher","first-page":"573","DOI":"10.1016\/s2468-1253(24)00390-x","article-title":"The intestinal barrier: a pivotal role in health, inflammation, and cancer","volume":"10","author":"Neurath","year":"2025","journal-title":"Lancet Gastroenterol. Hepatol."},{"key":"ref17","doi-asserted-by":"publisher","first-page":"2025018","DOI":"10.2141\/jpsa.2025018","article-title":"Effects of aging on the microbiota and inflammatory status of the intestinal and oviductal mucosa in laying hens","volume":"62","author":"Nii","year":"2025","journal-title":"J. Poult. Sci."},{"key":"ref18","doi-asserted-by":"publisher","first-page":"724006","DOI":"10.3389\/fnut.2021.724006","article-title":"Digestion and absorption of milk phospholipids in newborns and adults","volume":"8","author":"Nilsson","year":"2021","journal-title":"Front. 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Food Res."},{"key":"ref22","doi-asserted-by":"publisher","first-page":"102819","DOI":"10.1016\/j.anaerobe.2024.102819","article-title":"Bacteroides and related species: the keystone taxa of the human gut microbiota","volume":"85","author":"Shin","year":"2024","journal-title":"Anaerobe"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"1231","DOI":"10.3390\/nu2121231","article-title":"Chemistry and biochemistry of dietary polyphenols","volume":"2","author":"Tsao","year":"2010","journal-title":"Nutrients"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"112177","DOI":"10.1016\/j.mce.2024.112177","article-title":"Anti-steatotic effects of ppar-alpha and gamma involve gut-liver axis modulation in high-fat diet-fed mice","volume":"585","author":"Vasques-Monteiro","year":"2024","journal-title":"Mol. Cell. Endocrinol."},{"key":"ref25","doi-asserted-by":"publisher","first-page":"12786","DOI":"10.1021\/acs.jafc.9b06072","article-title":"Digestion, absorption, and metabolism characteristics of EPA-enriched phosphoethanolamine plasmalogens based on gastrointestinal functions in healthy mice","volume":"67","author":"Wang","year":"2019","journal-title":"J. Agric. Food Chem."},{"key":"ref26","doi-asserted-by":"publisher","first-page":"3138","DOI":"10.3382\/ps\/pez124","article-title":"Protocatechuic acid improved growth performance, meat quality, and intestinal health of Chinese yellow-feathered broilers","volume":"98","author":"Wang","year":"2019","journal-title":"Poult. 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