Effect of the administration of probiotics on the fecal microbiota of adult individuals

Probiotics have been used to ameliorate ailments by modulating gut microbiota. However, to date, the effects of probiotic supplementation on the composition of fecal microbiota in healthy adults remain obscure. In this study, nine healthy volunteers were recruited to take probiotics (a mixture of Lactobacillus casei Zhang, L. plantarum P‐8, and Bifidobacterium lactis V9, 2:2:3, 1 × 10(10) CFU/day) for 28 days. The fecal samples were collected at 0 and 28 days, and V4 of the 16S rRNA gene sequenced by Illumina MiSeq was used to analyze the fecal microbiota. The enterotype has been used to characterize the composition of gut microbiota. Nine adults were divided into Type P (fecal microbiota dominated by Prevotella, 4 adults) and Type B (fecal microbiota dominated by Bacteroides, 5 adults) based on an enterotype analysis. The responses of variation had been found in two enterotypes. The α‐diversity was not changed significantly after the administration of probiotics in both Type P and B. However, the community structure in Type B was substantially influenced. After the administration of probiotics, Weissella and Leuconostoc were significantly higher in Type P, while Collinsella significantly increased in Type B. The different pathways involving pathogen infections were downregulated at 28 days. The Type VI secretion system and the EHEC/EPEC pathogenicity signature were downregulated in Type B and Type P, respectively.