Abstract
OBJECTIVE Probiotics may improve intestinal health by modulating intestinal microbiota. However, the age-related variation in response to probiotic consumption is understudied. The aim of this study was to determine the effect of oral consumption of Lactobacillus plantarum P-8 (Lp-8) on human intestinal microflora, secretary immunoglobulin A (SIgA), total bile acids (TBAs), and short-chain fatty acids (SCFAs) of different aged adults. METHODS Thirty-three recruited individuals, including young (mean age 26 y), middle-aged (mean age 51 y), and elderly (mean age 76 y) volunteers, were given a single daily oral dose of Lp-8 (6 × 10(10) colony forming units) for 4 wk. Fecal samples were collected before starting, during, and after stopping Lp-8 intake. Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis, quantitative PCR, high-performance liquid chromatography, and enzyme-linked immunosorbent assay were used to detect for fecal microflora, SIgA, TBAs, and SCFAs. RESULTS Results showed an increase in Bifidobacterium (P < 0.05) and other beneficial bacteria, whereas Desulfovibrio (P < 0.05) and other opportunistic pathogens decreased after taking Lp-8 for 4 wk. Lp-8 consumption also affected fecal levels of SIgA, TBAs, and SCFAs. CONCLUSIONS Lp-8 administration could improve human gastrointestinal health. However, some of these effects were transient and gradually disappeared once the intervention was discontinued. Moreover, the extent of these desirable effects was age-related.
