{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T13:49:44Z","timestamp":1785764984975,"version":"3.56.0"},"reference-count":45,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2026,8,2]],"date-time":"2026-08-02T00:00:00Z","timestamp":1785628800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Jurong Agricultural Technology Innovation Fund","award":["ZA32411"],"award-info":[{"award-number":["ZA32411"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Escherichia coli (E. coli) infection in poultry triggers severe diarrhea and intestinal damage, ultimately disrupting gut function. Alanyl-glutamine (Aln-Gln) dipeptide not only exhibits potent gut-repairing efficacy but also restores barrier integrity and counters E. coli pathology through mucosal healing and immune modulation. In this study, the effects of Aln-Gln on microbiome modulation and intestinal integrity in growing hens challenged with E. coli were evaluated. The 250 healthy, Hy-line brown pullets (42 days old) were randomly divided into 5 experimental groups, each having five replicates of 10 chicks. Five dietary groups include a basal diet without added Aln-Gln and no E. coli challenge (NC), a basal diet without added Aln-Gln and orally administered 2.0 \u00d7 104 CFU\/mL E. coli suspension (C), a basal diet added 0.1% Aln-Gln and orally administered 2.0 \u00d7 104 CFU\/mL E. coli suspension (G1), a basal diet added 0.2% Aln-Gln and orally administered 2.0 \u00d7 104 CFU\/mL E. coli suspension (G2) and a basal diet added 0.3% Aln-Gln and orally administered 2.0 \u00d7 104 CFU\/mL E. coli suspension (G3). The results showed that dietary supplementation with 0.2% or 0.3% Aln-Gln effectively mitigated the adverse effects of an E. coli challenge, restoring body weight and feed intake to levels comparable to non-challenged controls. Aln-Gln supplementation (0.2\u20130.3%) reduced diarrhea severity, restored ileal morphology (villus height, crypt depth), improved antioxidant enzyme activity (GSH-Px, SOD), and reduced oxidative markers (MDA) (p &lt; 0.05). Aln-Gln decreased pro-inflammatory (IL-1\u03b2, IL-6, NO) and apoptotic (BAX) responses (p &lt; 0.05) and enhanced barrier integrity. It rebalanced gut microbiota by suppressing pathogenic Clostridium (75% in C vs. 29.9% in G3) and increasing beneficial Lactobacillus in G2\/G3 compared with C. These findings demonstrate Aln-Gln as a beneficial dietary additive that restores growth performance and gut integrity; reduces diarrhea severity, inflammation, and apoptosis; and improves antioxidant status as it rebalances gut microbiota.<\/jats:p>","DOI":"10.3390\/ijms27156936","type":"journal-article","created":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T12:57:56Z","timestamp":1785761876000},"page":"6936","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Alanyl-Glutamine Dipeptide Mitigates E. coli-Induced Pathogenesis in Hy-Line Brown Hens: Mechanistic Insights into Microbiome Modulation, Antioxidant Response, and Intestinal Integrity"],"prefix":"10.3390","volume":"27","author":[{"given":"Usman","family":"Nazir","sequence":"first","affiliation":[{"name":"College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China"},{"name":"College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6636-4606","authenticated-orcid":false,"given":"Zhi","family":"Yang","sequence":"additional","affiliation":[{"name":"Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6135-9987","authenticated-orcid":false,"given":"Muhammad Hammad","family":"Zafar","sequence":"additional","affiliation":[{"name":"College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3315-8993","authenticated-orcid":false,"given":"Xiaoli","family":"Wan","sequence":"additional","affiliation":[{"name":"College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haiming","family":"Yang","sequence":"additional","affiliation":[{"name":"College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1186\/s40104-021-00640-9","article-title":"Poultry gut health\u2014Microbiome functions, environmental impacts, microbiome engineering and advancements in characterization technologies","volume":"12","author":"Aruwa","year":"2021","journal-title":"J. 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