Lactobacillus paracasei A survives gastrointestinal passage and affects the fecal microbiota of healthy infants
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- 作者：Marta Marzotto ; Claudio Maffeis ; Thomas Paternoster ; Rossano Ferrario ; Lucia Rizzotti ; Maristella Pellegrino ; Franco Dellaglio and Sandra Torriani
- 关键词：Lactobacillus ; Probiotic strains ; Fermented milk ; Infants ; Gastrointestinal content ; PCR-DGGE
- 刊名：Research in Microbiology
- 出版年：2006
- 出版时间：November 2006
- 年：2006
- 卷：157
- 期：9
- 页码：857-866
- 全文大小：622 K
文摘
This study focuses on the potentiality of a putative probiotic strain, Lactobacillus paracasei A, to survive gastrointestinal (GI) passage and modulate the resident microbiota of healthy infants. In a placebo-controlled study, 26 children aged 12–24 months received 100 g/day of either fermented milk containing strain A or pasteurized yogurt for four weeks. Fecal samples were analyzed before starting the administration, after 1, 3 and 4 weeks of consumption and after washout. The fate of strain A was followed by means of a newly developed PCR targeting a strain-specific genomic marker. The composition and dynamics of fecal microbial communities during the study were analyzed by culturing on selective media and by the PCR-denaturing gradient gel electrophoresis (DGGE) technique using universal and group-specific (Lactobacillus and Bifidobacterium) primers. The variation in enzymatic activities in infant feces during probiotic consumption was also analyzed. Strain A survived in fecal samples in most (92 % ) of the infants examined after 1 week of consumption, and temporarily dominated the intestinal Lactobacillus community. The administration of L. paracasei A led to a significant increment in the Lactobacillus population, while a moderate effect upon the main bacterial groups in the GI ecosystem was observed. Strain A also affected the diversity of the Lactobacillus and Bifidobacterium populations. The fecal bacterial structure of 1–2-year-old infants seems to combine neonate and adult-like features. The microbiota of these subjects promptly responded to probiotic consumption, later restoring the endogenous equilibrium.