母乳及婴儿粪便菌群分析及功能菌株筛选

目的 探究母乳喂养婴儿粪便菌群及母乳菌群相关性, 获得具有潜在益生功能菌株。方法 对健康母子母乳及婴儿粪便样本进行Illumina高通量测序, 探究母乳与婴儿粪便样本菌群结构组成, 母乳菌群在婴儿肠道垂直传递情况。通过体外益生性质研究, 对分离的菌株进行筛选。结果 母乳中的主要菌科为肠杆菌科、莫拉氏菌科、葡萄球菌科和链球菌科; 而婴儿粪便中主要为肠杆菌科和双歧杆菌科。母乳对婴儿肠道菌群的平均贡献率为44.90%。根据其表面疏水性、模拟胃肠道耐受性和对细胞的黏附性质的研究, 从123株分离菌株中筛选出8株具有益生功能菌株, 分别为2株假小链双歧杆菌、1株两歧双歧杆菌和5株粪肠球菌。 结论 母乳菌群与婴儿肠道菌群密切相关, 存在菌群垂直传递的情况。最终获得8株性能优良的益生菌株, 为开发益生菌补充剂提供理论基础。

Comparative analysis of microbiotas in breast milk and infant stools and screening of functional strains

Objective To explore the correlation between stools and breast milk of exclusively breastfed infants, and obtain potential probiotic strains. Methods Illumina high-throughput sequencing was performed on breast milk and infant fecal samples of healthy mother and child to explore the composition of the microflora of breast milk and infant fecal samples, and the vertical transmission of breast milk microflora in the infant intestine. Furthermore, the isolated strains in breast milk and infant stools were evaluated and selected based on their probiotic properties in vitro. Results Enterobacteriaceae, Moraxellaceae, Staphylococcaceae, and Streptococcaceae were major families in breast milk, while Enterobacteriaceae and Bifidobacteriaceae were predominant in infant stool. The average contribution rate of breast milk to the intestinal flora of infants was 44.90%. Among the 123 isolated strains, 8 strains were screened based on their hydrophobicity, tolerance to intestinal conditions and adhesion to cells, and identified as 2 Bifidobacterium pseudocatenulatum strains, 1 Bifidobacterium bifidum strain, and 5 Enterococcus faecalis strains. Conclusion Breast milk microbiota is closely related to infant gut microbiota, and there is vertical transmission of microbiota. Finally, 8 strains of probiotics with good performance are screened, which provides a theoretical basis for the development of probiotic supplements.