| Lactobacillus delbrueckii has attracted much attention because of its played an important role in regulating intestinal microecological balance,preventing and treating diarrhea,regulating immunity,promoting growth and improving meat quality.However,there are few studies on the effect of lactobacillus on intestinal microbial diversity and gut liver axis metabolism of weaned piglets.Eighty 28d old weaned piglets were randomly divided into 2 groups with 4 replicates in each group（n=10 piglet per replicate）.The experiment lasted for 28 days,piglets were fed a basic diet（control group）and a basic diet containing 0.1%Lactobacillus delbrueckii(≥1.0×1010CFU/g)respectively.The results as follows:1.Effects of lactobacillus delbrueckii on production performance of weaned pigletsLactobacillus delbrueckii could enhance growth performance of weaned piglets significantly throughout the entire experimental period.Compare with the control group,in the early stage of the experiment（0-14d）,the ADG of weaned piglets increased by 9.87%after supplemented Lactobacillus delbrueckii（P<0.05）,while diarrhea rate decreased significantly（P<0.05）.In the entire period（0-28d）,the ADG of weaned piglets increased by6.75%after supplemented Lactobacillus delbrueckii（P<0.05）.The content of TP and INS on the 14thday,HDL and INS on the 28thday which in serum were significantly increased after supplemented Lactobacillus delbrueckii（P<0.05）.The serum levels of ALT and GC on the28thday were significantly reduced（P<0.05）.2.Effects of lactobacillus delbrueckii on intestinal morphology and digestive function of weaned pigletsCompared with the control group,the jejunum V/C ratio,ileum villus height and V/C ratio of weaned piglets on the 28thday were significantly increased,and the jejunum crypt depth was significantly decreased（P<0.05）.The p H values of duodenum and ileum of weaned piglets on the 28thday were significantly decreased（P<0.05）.The contents of lactase,sucrase and maltase in duodenum,jejunum and ileum of weaned piglets on the14thday were significantly increased（P<0.05）,and the contents of lactase,sucrase and maltase in jejunum on the 28thday were significantly increased（P<0.05）.The amylase content in duodenum and jejunum of weaned piglets on day 28 was significantly increased（P<0.05）.The expressions of glucose transporters SGLT1 and GLUT2,PI3K and Akt proteins in duodenum,jejunum and ileum mucosa of weaned piglets on the 14thday and on the 28thday were significantly increased（P<0.05）.3.Effects of lactobacillus delbrueckii on intestinal microbial and fatty acid of weaned pigletsCompared with the control group,Lactobacillus delbrueckii supplementation had an effect on the microbial diversity in cecum and colon contents of weaned piglets,and increased theαdiversity in cecum and colon.Compared with the control group,Lactobacillus delbrueckii supplementation decreased the content of Proteobacteria in cecum and colon,and increased the content of beneficial genera such as Lactobacillus and Ruminococcus.Meanwhile,Lactobacillus delbrueckii supplementation increased the contents of butyric acid,isobutyric acid and isovaleric acid in colonic digesta of weaned piglets on the 28thday.This suggests that Lactobacillus delbrueckii may promote a more host-friendly symbiotic gut flora that regulates growth,health,digestion and metabolism of piglets by altering the diversity and structure of microorganisms in the gut.4.Effects of lactobacillus delbrueckii on liver metabolism of weaned pigletsIn the early stage of the experiment,Lactobacillus delbrueckii supplementation increased the contents of L-phenylalanine and L-lysine in liver,decreased the contents of L-alanine,and enhanced the Aminoacyl t RNA biosynthesis pathway of weaned piglets.In the late stage of the experiment,Lactobacillus delbrueckii supplementation increased the content of Arachidonic acid in liver,and enhanced the Arachidonic acid metabolism pathway of weaned piglets.Intestinal microbial and its metabolites may be involved in regulating these processes.This suggests that Lactobacillus delbrueckii supplementation reduced liver damage and metabolic dysfunction,improves the antioxidant function of the liver by improving its ability to metabolize glucolipid,leading to a healthier liver.5.Effects of lactobacillus delbrueckii on intestinal microflora,performance and liver metabolism of weaned pigletsSpearman correlation analysis showed that there was a certain correlation among growth performance,intestinal microbial diversity and glucolipid metabolism after supplemented with Lactobacillus delbrueckii of weaned piglets.During the whole experiment period,the ADG and EE digestibility of weaned piglets were significantly positively correlated with the abundance of Bifidobacteria,Lactobacillus and Ruminococcus.There was a certain correlation between the abundance of intestinal microorganisms and the content of fatty acids in the colon.In the later stage of the experiment,the contents of butyric acid,isobutyric acid and isovaleric acid in the colon were positively correlated with the abundance of the Ruminococcus.On the 14thday of the experiment,Lactobacillus was positively correlated with DL-phenylalanine,L-（+）Lysine and L-phenylalanine.On the 28thday of the experiment,acetic acid had a significant positive correlation with liver Leucylproline content.There was a significant positive correlation between butyric acid and the contents of 11,12-Epoxy-（5Z,8Z,11Z）-icosatrienoic acid in liver.In conclusion,Lactobacillus delbrueckii supplementation can promote the growth of weaned piglets,and reduce weaning stress.With the colonization of Lactobacillus delbrueckii in the intestinal of piglets,intestinal digestive enzyme activity,glucose metabolism related pathway expression,nutrient digestion and metabolism can be improved,intestinal microbial diversity can be improved,liver health and metabolic function can be improved.Lactobacillus delbrueckii supplementation can reduce the damage of weaning stress on intestinal mucosa morphology and liver by improving the intestinal microbial barrier function of piglets,and maintain the normal physiological function.Lactobacillus delbrueckii supplementation regulates the Aminoacyl t RNA biosynthesis and the Arachidonic acid metabolism pathway of piglets through microbial metabolites such as lactic acid,butyric acid and isobutyric acid,and affects the digestion and metabolism of nutrients such as glucose and lipids of piglets,thus improving the performance of weaned piglets. |
