[1] 国家市场监督管理总局,国家标准化管理委员会.产蛋鸡和肉鸡配合饲料:GB/T 5916-2020[S].北京:中国标准出版社,2020. State Administration for Market Regulation,Standardization Administration of the People's Republic of China.Formula feeds for layers and broilers:GB/T 5916-2020[S].Beijing:Standards Press of China,2020.(in Chinese)
[2] MORAN E T,Jr.Nutrients central to maintaining intestinal absorptive efficiency and barrier integrity with fowl[J].Poultry Science,2017,96(5):1348-1363.

[3] GORK A S,USUI N,CERIATI E,et al.The effect of mucin on bacterial translocation in Ⅰ-407 fetal and Caco-2 adult enterocyte cultured cell lines[J].Pediatric Surgery International,1999,15(3/4):155-159.
[4] BURRIN D G,STOLL B,JIANG R,et al.Minimal enteral nutrient requirements for intestinal growth in neonatal piglets:how much is enough?[J].The American Journal of Clinical Nutrition,2000,71(6):1603-1610.

[5] GUAY F,DONOVAN S M,TROTTIER N L.Biochemical and morphological developments are partially impaired in intestinal mucosa from growing pigs fed reduced-protein diets supplemented with crystalline amino acids[J].Journal of Animal Science,2006,84(7):1749-1760.

[6] KAEWTAPEE C,BURBACH K,TOMFORDE G,et al.Effect of
Bacillus subtilis and
Bacillus licheniformis supplementation in diets with low-and high-protein content on ileal crude protein and amino acid digestibility and intestinal microbiota composition of growing pigs[J].Journal of Animal Science and Biotechnology,2017,8:37.
[7] LUO Z,LI C B,CHENG Y F,et al.Effects of low dietary protein on the metabolites and microbial communities in the caecal digesta of piglets[J].Archives of Animal Nutrition,2015,69(3):212-226.

[8] ZHOU L P,FANG L D,SUN Y,et al.Effects of the dietary protein level on the microbial composition and metabolomic profile in the hindgut of the pig[J].Anaerobe,2016,38:61-69.
[9] MCWHORTER T J,CAVIEDES-VIDAL E,KARASOV W H.The integration of digestion and osmoregulation in the avian gut[J].Biological Reviews of the Cambridge Philosophical Society,2009,84(4):533-565.

[10] WANG W W,QIAO S Y,LI D F.Amino acids and gut function[J].Amino Acids,2009,37(1):105-110.

[11] LAUDADIO V,PASSANTINO L,PERILLO A,et al.Productive performance and histological features of intestinal mucosa of broiler chickens fed different dietary protein levels[J].Poultry Science,2012,91(1):265-270.

[12] KESHAVARZ K,AUSTIC R E.The use of low-protein, low-phosphorus, amino acid-and phytase-supplemented diets on laying hen performance and nitrogen and phosphorus excretion[J].Poultry Science,2004,83(1):75-83.

[13] SHIM M Y,SONG E,BILLARD L,et al.Effects of balanced dietary protein levels on egg production and egg quality parameters of individual commercial layers[J].Poultry Science,2013,92(10):2687-2696.

[14] WANG H,WANG X J,ZHAO J P,et al.Low protein diet supplemented with crystalline amino acids suppressing appetite and apo-lipoprotein synthesis in laying hens[J].Animal Feed Science and Technology,2020,266:114533.
[15] PARENTEAU I A,STEVENSON M,KIARIE E G.Egg production and quality responses to increasing isoleucine supplementation in Shaver White hens fed a low crude protein corn-soybean meal diet fortified with synthetic amino acids between 20 and 46 weeks of age[J].Poultry Science,2020,99(3):1444-1453.

[16] SUN M F,MA N,LIU H,et al.The optimal dietary arginine level of laying hens fed with low-protein diets[J].Journal of Animal Science and Biotechnology,2022,13(1):63.
[17] 凌晓波.家禽肠道健康及其营养调控措施探讨[J].吉林畜牧兽医,2019,40(6):30-31. LING X B.Intestinal health of poultry and its nutritional control measures[J].Jilin Animal Husbandry and Veterinary Medicine,2019,40(6):30-31.(in Chinese)
[18] BAUMGART D C,DIGNASS A U.Intestinal barrier function[J].Current Opinion in Clinical Nutrition and Metabolic Care,2002,5(6):685-694.

[19] ARRIETA M C,BISTRITZ L,MEDDINGS J B.Alterations in intestinal permeability[J].Gut,2006,55(10):1512-1520.

[20] LIBONI K C,LI N,SCUMPIA P O,et al.Glutamine modulates LPS-induced IL-8 production through IκB/NF-κB in human fetal and adult intestinal epithelium[J].The Journal of Nutrition,2005,135(2):245-251.

[21] HAMPSON D J.Alterations in piglet small intestinal structure at weaning[J].Research in Veterinary Science,1986,40(1):32-40.

[22] EGE G,BOZKURT M,KOÇER B,et al.Influence of feed particle size and feed form on productive performance,egg quality,gastrointestinal tract traits,digestive enzymes,intestinal morphology,and nutrient digestibility of laying hens reared in enriched cages[J].Poultry Science,2019,98(9):3787-3801.

[23] 张丽明.低蛋白日粮调整氨基酸平衡对肉鸡氮代谢及肠道氨基酸转运载体相关基因表达的影响[D].硕士学位论文.长春:吉林大学,2017. ZHANG L M.Effects of amino acid balance in low protein diets on nitrogen metabolism and intestinal amino acid transporter related genes expression in broilers[D].Master's Thesis.Changchun:Jilin University,2017.(in Chinese)
[24] ALLAMEH S,TOGHYANI M.Effect of dietary valine supplementation to low protein diets on performance,intestinal morphology and immune responses in broiler chickens[J].Livestock Science,2019,229:137-144.
[25] 陶红旭,隋炳毅,龙烁,等.低蛋白日粮对蛋鸡生产性能和蛋品质的影响[J].中国家禽,2014,36(24):38-42. TAO H X,SUI B Y,LONG S,et al.Effect of low-protein diet on production performance and egg quality of laying hens[J].China Poultry,2014,36(24):38-42.(in Chinese)
[26] ZAEFARIAN F,ZAGHARI M,SHIVAZAD M.The threonine requirements and its effect on growth performance and gut morphology of broiler chicken fed different levels of protein[J].International Journal of Poultry Science,2008,7(12):1207-1215.

[27] 蔡元丽.影响肠道屏障功能的因素及营养调控措施[J].齐鲁工业大学学报,2019,33(1):41-47. CAI Y L.Factors influencing on intestinal barrier function and nutrient modulation[J].Journal of Shandong Institute of Light Industry (Natural Science Edition),2019,33(1):41-47.(in Chinese)
[28] FURNESS J B,KUNZE W A,CLERC N.Nutrient tasting and signaling mechanisms in the gut.Ⅱ.The intestine as a sensory organ:neural,endocrine,and immune responses[J].The American Journal of Physiology,1999,277(5):G922-G928.
[29] MAJKA G,WIECEK G,S'RÓTTEK M,et al.The impact of lactoferrin with different levels of metal saturation on the intestinal epithelial barrier function and mucosal inflammation[J].BioMetals,2016,29(6):1019-1033.

[30] CHOI E Y,HWANG H J,KIM I H,et al.Protective effects of a polysaccharide from
Hizikia fusiformis against ethanol toxicity in rats[J].Food and Chemical Toxicology,2009,47(1):134-139.

[31] SCHOULTZ I,KEITA Å V.Cellular and molecular therapeutic targets in inflammatory bowel disease-focusing on intestinal barrier function[J].Cells,2019,8(2):193.
[32] SUZUKI T.Regulation of intestinal epithelial permeability by tight junctions[J].Cellular and Molecular Life Sciences,2013,70(4):631-659.

[33] VICENTE Y,DA ROCHA C,YU J K,et al.Architecture and function of the gastroesophageal barrier in the piglet[J].Digestive Diseases and Sciences,2001,46(9):1899-1908.

[34] TSUKITA S,FURUSE M,ITOH M.Multifunctional strands in tight junctions[J].Nature Reviews:Molecular Cell Biology,2001,2(4):285-293.

[35] AZZAM M M M,DONG X Y,ZOU X T.Effect of dietary threonine on laying performance and intestinal immunity of laying hens fed low-crude-protein diets during the peak production period[J].Journal of Animal Physiology and Animal Nutrition,2017,101(5):e55-e66.
[36] DONG X Y,AZZAM M M M,ZOU X T.Effects of dietary
L-isoleucine on laying performance and immunomodulation of laying hens[J].Poultry Science,2016,95(10):2297-2305.

[37] 徐子伟.仔猪肠道损伤修复营养调控及其机制和应用[J].动物营养学报,2014,26(10):3033-3045. XU Z W.Mechanism and application for nutritional regulations of intestine damage repair in piglets[J].Chinese Journal of Animal Nutrition,2014,26(10):3033-3045.(in Chinese)
[38] 陈渝,陈代文,毛湘冰,等.精氨酸对免疫应激仔猪肠道组织Toll样受体基因表达的影响[C]//第五届中国畜牧科技论坛论文集.重庆:中国畜牧兽医学会,2011. CHEN Y,CHEN D W,MAO X B,et al.Effect of arginine supplementation on expression of Toll-like receptors genes of gut in weaned piglets during immune challenge[C]//Proceedings of the 5th China Animal Husbandry Science and Technology Forum.Chongqing:Chinese Association of Animal Science and Veterinary Medicine,2011.(in Chinese)
[39] ZHOU J M,QIU K,WANG J,et al.Effect of dietary serine supplementation on performance,egg quality,serum indices,and ileal mucosal immunity in laying hens fed a low crude protein diet[J].Poultry Science,2021,100(12):101465.
[40] 张日俊,潘淑媛,白永义,等.微生物饲料添加剂益生康对肉仔鸡营养代谢与免疫功能的调控机理[J].中国农业大学学报,2005,10(3):40-47. ZHANG R J,PAN S Y,BAI Y Y,et al.Modulating mechanism of
Yishengkang as feed additives on nutrient metabolism and immune function in broiler chickens[J].Journal of China Agricultural University,2005,10(3):40-47.(in Chinese)
[41] 孙小沛,杨在宾,李兆勇,等.地衣芽孢杆菌与日粮蛋白水平对肉鸡生产性能、肠道环境及免疫器官指数的影响[J].饲料工业,2013,34(23):40-46. SUN X P,YANG Z B,LI Z Y,et al.Effects of
Bacillus licheniformis and dietary protein levels on growth performance,intestinal health and immune organ indexes of broilers[J].Feed Industry,2013,34(23):40-46.(in Chinese)
[42] NATIVIDAD J M M,VERDU E F.Modulation of intestinal barrier by intestinal microbiota:pathological and therapeutic implications[J].Pharmacological Research,2013,69(1):42-51.

[43] HAYES C L,DONG J,GALIPEAU H J,et al.Commensal microbiota induces colonic barrier structure and functions that contribute to homeostasis[J].Scientific Reports,2018,8(1):14184.
[44] SONNENBURG J L,BÄCKHED F.Diet-microbiota interactions as moderators of human metabolism[J].Nature,2016,535(7610):56-64.

[45] FENG Q Q,CHEN W D,WANG Y D.Gut microbiota:an integral moderator in health and disease[J].Frontiers in Microbiology,2018,9:151.
[46] BRESTOFF J R,ARTIS D.Commensal bacteria at the interface of host metabolism and the immune system[J].Nature Immunology,2013,14(7):676-684.

[47] DE CESARE A,FARIA DO VALLEÌ,SALA C,et al.Effect of a low protein diet on chicken ceca microbiome and productive performances[J].Poultry Science,2019,98(9):3963-3976.

[48] MA M,GENG S J,LIU M L,et al. Effects of different methionine levels in low protein diets on production performance,reproductive system,metabolism,and gut microbiota in laying hens[J].Frontiers in Nutrion,2021,8:739676.
[49] DONG X Y,AZZAM M M M,ZOU X T.Effects of dietary threonine supplementation on intestinal barrier function and gut microbiota of laying hens[J].Poultry Science,2017,96(10):3654-3663.

[50] PRIOULT G,FLISS I,PECQUET S.Effect of probiotic bacteria on induction and maintenance of oral tolerance to β-lactoglobulin in gnotobiotic mice[J].Clinical and Diagnostic Laboratory Immunology,2003,10(5):787-792.
[51] BEAGLEY K W,HUSBAND A J.Intraepithelial lymphocytes:origins,distribution,and function[J].Critical Reviews in Immunology,1998,18(3):237-254.

[52] ZHOU J M,ZHANG H J,WU S G,et al.Supplemental xylooligosaccharide modulates intestinal mucosal barrier and cecal microbiota in laying hens fed oxidized fish oil[J].Frontiers in Microbiology,2021,12:635333.
[53] KUMAR D,RAGINSKI C,SCHWEAN-LARDNER L K,et al.Assessing the response of hen weight,body composition,feather score,egg quality,and level of excreta nitrogen content to digestible balanced proteinintake of laying hens[J].Canadian Journal of Animal Science,2018,98(4):619-630.

[54] LI J M,ZHANG X Y,YUAN C,et al.Effects of dietary
L-thronine levels on antioxidant capacity digestive enzyme on antioxdant capacity,digestive enzyme activities,and antibody production of
Xinyang green shell laying hens[J].Journal of Applied Poultry Research,2016,25(3):422-427.

[55] VAN DER SLUIS M,SCHAART M W,DE KONING B A E,et al.Threonine metabolism in the intestine of mice:loss of mucin 2 induces the threonine catabolic pathway[J].Journal of Pediatric Gastroenterology and Nutrition,2009,49(1):99-107.

[56] AZZAM M M M,DONG X Y,XIE P,et al.Influence of
L-threonine supplementation on goblet cell numbers, histological structure and antioxidant enzyme activities of laying hens reared in a hot and humid climate[J].British Poultry Science,2012,53(5):640-645.