Table_1_Coevolution of specific gut microbiota of Min pig with host cold adaptation through enhanced vitamin B1 synthesis.xls

Min pigs exhibit remarkable cold tolerance, where vitamin B1 synthesis by gut microbiota is crucial for the host's energy metabolism. However, the role of this synthesis in cold adaptation of Min pigs are not yet fully understood. This study utilized 16S rRNA amplicon and metagenomic sequencing to examine seasonal variations in the gut microbiota of Min pigs. Results indicated a significant rise in microbial diversity in winter, with the Bacteroidetes group being the most notably increased. The vitamin B1 biosynthetic pathway was significantly enriched during winter, with six significantly upregulated genes (ThiC, ThiD, ThiE, ThiG, ThiH, and ThiL) showing strong evidence of purifying selection. Among the six vitamin B1 synthesis genes significantly upregulated during winter, the increase was mainly due to a marked elevation in several sequences from specific microbial species. Binding energy analysis revealed that, except for ThiL, the average substrate binding energy of the top 10 sequences with the largest seasonal differences was significantly lower than those of the 10 sequences with the smallest differences. Furthermore, most of these sequences were uniquely prevalent in Min pigs and were not found in the homologous sequences of Duroc pigs. Bacteroidetes and Bacteroidales were identified as the primary contributors to these gene sequences. This research provides valuable insights for developing innovative cold-resistant feed and probiotics.

民猪（Min pigs）展现出优异的耐寒特性，其中肠道菌群（gut microbiota）介导的维生素B1（vitamin B1）合成对于宿主的能量代谢至关重要。然而，该合成过程在民猪冷适应中的作用尚未完全阐明。本研究采用16S rRNA扩增子（16S rRNA amplicon）测序与宏基因组测序（metagenomic sequencing）技术，解析民猪肠道菌群的季节动态变化。结果显示，冬季肠道菌群多样性显著升高，拟杆菌门（Bacteroidetes）类群的丰度增幅最为显著。冬季期间，维生素B1生物合成通路显著富集，6个显著上调的基因（ThiC、ThiD、ThiE、ThiG、ThiH及ThiL）呈现出强烈的纯化选择（purifying selection）信号。在冬季显著上调的6个维生素B1合成基因中，其表达上调主要源于特定微生物类群的序列丰度显著提升。结合能分析结果显示，除ThiL外，季节差异最显著的前10条序列的平均底物结合能（substrate binding energy），显著低于季节差异最微小的10条序列的平均底物结合能。进一步研究发现，上述多数序列仅在民猪中特异性存在，未在杜洛克猪（Duroc pigs）的同源序列中检出。拟杆菌门（Bacteroidetes）及拟杆菌目（Bacteroidales）是上述基因序列的主要贡献类群。本研究为开发新型耐寒饲料与益生菌制剂提供了重要理论参考。