Screening Of Candidate Gut Microbe And Metablites Of Backfat In Pregnant Sows

The backfat in the pregnancy period was an important factor in reproduction performance in sows.The abnormal backfat(too high or too low)results in a reproduction performance decrease,usually.Thus,normal backfat during the pregnancy period was very important to maintain production efficiency.The backfat was the key index to judge the level of lipidosis in the pig.As we know,the gut microbe can directly or indirectly regulate lipidosis and result in changes in backfat.The metabolism can identify the markers of gut metabolites,and analyze the relationship between gut microbe and host phenotype.To identify the microbe and metabolite markers of backfat in the sow pregnant period,we used the 16 S rRNA,metagenome,and metabolome to explore the relationship between backfat and gut microbe and metabolites.Our results provided the reference to enhance the reproduction performance through microbe and metabolites to regulate backfat using in sow pregnant periods.The results of our study were as follows:(1)We selected 104 sows(24 Large white with a pregnancy of 60 days,19 Lardance with a pregnancy of 60 days,42 Large white with a pregnancy of 107 days,and 19 Lardance with a pregnancy of 107 days)out of 523 pregnant sows(308 Large white and 215 Landrace)to constitute the high backfat group(four groups)and the low backfat group(four groups).The feces of the animals were collected to carry out the16 S rRNA sequence.The result showed that the diversity in the high backfat group was higher than in the low backfat group(P>0.05).The main phylum was both the Firmicutes and Bacteroidetes,and the common main genus was the Christensenellaceae＿R-7＿group,Ruminococcaceae＿UCG-002,Escherichia-Shigella,Methanobrevibacte,Ruminococcaceae＿UCG-005,and Ruminococcaceae＿NK4A214＿group in pregnancy 60 days and 107 days.The common difference microbes,including the Candidatus＿Soleaferrea,norank＿f＿Erysipelotrichaceae,Escherichia＿Shigella,Collinsella,Catenibacterium,Holdemanella and p＿1088＿a5＿gut＿group were obtained via Stamp and LEf Se methods.The relative abundance of Candidatus＿Soleaferrea in the high backfat group was significantly higher than low backfat group(P<0.05),however the relative abundance of norank＿f＿Erysipelotrichaceae,Escherichia＿Shigella,Collinsella,Catenibacterium,Holdemanella and p＿1088＿a5＿gut＿group in the high backfat group were significantly lower than low backfat group(P<0.05).Importantly,the relative abundance of norank＿f＿Erysipelotrichaceae was the difference microbe in the three groups.(2)A total of 99 samples from high backfat and low backfat group(23 Large white with a pregnancy of 60 days,17 Lardance with a pregnancy of 60 days,40 Large white with a pregnancy of 107 days,and19 Lardance with a pregnancy of 107 days)were used to complete the metabolome.The results illustrated that there were 1,354 and 1,206 metabolites were identified in positive and negative ion models.A total of781 different metabolites were obtained,and most of them were related to fat synthesis and degradation.The different metabolites were enriched in the 101 KEGG pathway,and some of them were the fat-relate pathways.(3)To further explain the candidate species and pathways of backfat in the sow pregnancy period,a total of 30 samples from high backfat and low backfat group(7 Large white with a pregnancy of 60 days,8 Lardance with a pregnancy of 60 days,7 Large white with a pregnancy of 107 days,and 8 Lardance with a pregnancy of 107 days)were used to implement the metagenome sequence.The result showed that the main phylum was the Firmicutes,Proteobacteria,Actinobacteria and Euryarchaeota;the main genus were Clostridium,Lactobacillus and Romboutsia;and the main species were Romboutsia ilealis,Turicibacter sp.H121,Lactobacillus amylovorus and Lactobacillus johnsonii.There were 66 different genus and 53 different species were obtained through Stamp analysis,and some of them were related to fat synthesis and degradation.The relative abundance of Erysipelothrix sp.HDW6 A in all low backfat group were higher than high backfat group,and significant difference in three low backfat group and high backfat group(P<0.05).The Erysipelothrix sp.HDW6 A can be used as the candidate microbe marker of backfat in sows.(4)The Spearman analysis between different microbe and different metabolites found that most of the microbe were significant correlate with metabolites(P<0.05).The 45 difference microbe from 16 S rRNA and 603 difference metabolites constituted 1,460 significant related pairs,and the ranges of spearman coefficient were-0.54～-0.3 and0.3～0.49.The 66 different genus from metagenome and 603 different metabolites constituted 2,985 significant related pairs,and the ranges of spearman coefficient were-0.75～-0.44 and 0.44～0.82.The 53 difference species from metagenome and 603 difference metabolites constituted2,513 significant related pairs,and the ranges of the spearman coefficient were-0.72～-0.44 and 0.44～0.82.The Erysipelothrix sp.HDW6 A and difference metabolites constituted 255 significant related pairs,which were the maximal network.The top 20 significant related metabolites with Erysipelothrix sp.HDW6 A contained Tetrahydrocortisone and glycocholic acid,which both were sterol.Thus,we guess that the Erysipelothrix sp.HDW6 A may affect the backfat of pregnancy sows through tetrahydrocortisone,glycocholic acid and other sterol.