Lactobacillus plantarum or Macleaya cordata affects the biosynthesis of vitamin B12 by ileal microbiota of weaned goats: a metagenomics study

Abstract:

[Objective] To explore the vitamin B₁₂ synthesis in ruminant gastrointestine and evaluate the effect of Lactobacillus plantarum (LAC) or Macleaya cordata (MAC) on the synthesis of vitamin B₁₂ by the ileal microbiota of weaned goats. [Methods] Twenty weaned black goats with similar body weights and ages were randomly assigned into a control group (n=7), a LAC group (n=7), and a MAC group (n=6). The control group was fed with a normal diet, and the LAC and MAC groups with normal diets supplemented with LAC P-8 at 4.0×10⁹ CFU/g and 0.3 g/d MAC (3.75%), respectively. The contents in the middle section of ileum were collected for metagenomic sequencing. VB12Path and KEGG were employed to analyze the sequencing results. [Results] A total 55 and 49 key genes associated with vitamin B₁₂ synthesis were identified in VB12Path and KEGG, respectively. The alpha and beta diversity of genes involved in vitamin B₁₂ synthesis were changed by the supplementation of LAC or MAC (P<0.05). Compared with that in the control group, the diversity of the LAC group showed little difference and that of the MAC group decreased (P<0.05). The abundance of genes involved in precorrin-2 synthesis pathway, aerobic and anaerobic synthesis pathways, salvage pathway, and Post-AdoCbi-P pathway (e.g., gltX, cbiT, cobT, and btuD) in LAC and MAC groups was higher than that in the control group. [Conclusion] The supplementation of LAC or MAC enhanced the synthesis of vitamin B₁₂ by ileal microorganisms. This study expands our understanding and analytical method of the microbial vitamin B₁₂ synthesis.