Investigating the regulatory effect of Shen Qi Bu Qi powder on the gastrointestinal flora and serum metabolites in calves.

Abstract

<h4>Object</h4>To investigate the effects of Shen Qi Bu Qi Powder (SQBQP) on the average daily gain, blood indexes, gastrointestinal microflora, and serum metabolites of calves.<h4>Methods</h4>A total of 105 calves were randomly assigned to three groups (n = 35 per group): the control group (C, fed with a basal diet for 21 days) and two treatment groups (SQBQP-L and SQBQP-H, fed with the basal diet supplemented with 15 and 30 g/kg of SQBQP), respectively for 21 days. The active components of SQBQP were identified using LC-MS/MS. Serum digestive enzymes and antioxidant indices were determined by ELISA kits and biochemical kits, respectively. Serum differential metabolites were analyzed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS), while flora in rumen fluid and fecal were analyzed by 16S rDNA sequencing. Further correlation analysis of gastrointestinal flora and serum metabolites of SQBQP-H and C groups were performed with Spearman's correlation.<h4>Results</h4>The principal active components of SQBQP mainly includes polysaccharides, flavonoids, and organic acids. Compared to the control group (C), calves in the SQBQP-H (high dose) and SQBQP-L (low dose) groups showed a significant increase in serum amylase (AMS) levels (<i>P</i><0.001), while lipase content significantly decreased (<i>P</i><0.05). Additionally, the average daily gain, T-AOC, and cellulase content of calves in the SQBQP-H group significantly increased (<i>P</i><0.05). <i>Proteobacteria</i> and <i>Succinivibrio</i> in the rumen flora of the SQBQP-H group was significantly lower than that of the C group (<i>P</i><0.05). The relative abundance of <i>Proteobacteria, Actinobacteria, Candidatus_Saccharibacteria, Deinococcus_Thermus, Cyanobacteria</i>, and <i>Succinivibrio</i> in the SQBQP-H group was significantly increased (<i>P</i><0.05), while the relative abundance of <i>Tenericutes</i> and <i>Oscillibacter</i> was significantly decreased (<i>P</i><0.05). Serum metabolomics analysis revealed 20 differential metabolites, mainly enriched in amino acid biosynthesis, β-alanine metabolism, tyrosine, and tryptophan biosynthesis metabolic pathways (<i>P</i><0.05). Correlation analysis results showed that <i>Butyrivibrio</i> in rumen flora and <i>Oscillibacter_valericigenes</i> in intestinal flora were significantly positively correlated with average daily gain, serum biochemical indexes, and differential metabolite (-)-Epigallocatechin (R>0.58, <i>P</i><0.05).<h4>Conclusion</h4>SQBQP can promote calves weight gain and enhance health by modulating gastrointestinal flora and metabolic processes in the body.