Impact of Lactobacillus plantarum ST-III on the composition of infant gut microbiota and its potential synergism with breast milk and infant formula as revealed by an in vitro study

Several studies have demonstrated the effect of probiotics on prevention of diseases in infants. However, the mechanisms remain not fully addressed. In the present study a modified standard ileal efflux medium (SIEM) was exploited in an in vitro analysis and the effect of Lactobacillus plantarum ST-III on the composition of infant gut microbiota was examined in I-chip analysis followed by qPCR confirmation. Also, the effect of ST-III, when administered in combination with breast milk and infant formula, was investigated. The results showed that ST-III could reduce the overall amount of Enterobacteria and Bacteroidetes bacteria, yet increase the abundance of Lactobacillus and certain Bifidobacterium species. Notably, some species/genus of bacteria of medical significance, e.g., Alcaligenaceae sutterella and Desulfovibrio bacteria were inhibited by ST-III. Moreover, co-administration of breast milk or infant formula could increase the abundance of ST-III, suggesting a synergistic effect between ST-III and infant formula and breast milk.