Gut microbiota of healthy elderly NSAID users is selectively modified with the administration of Lactobacillus acidophilus NCFM and lactitol

Abstract

Ageing changes gut microbiota composition and alters immune system function. Probiotics, prebiotics and synbiotics may improve the health status of elderly individuals by modifying the intestinal environment and the microbiota composition, and by stimulating the immune system. In this work, we studied the effects of synbiotic supplementation on the gut microbiota of healthy elderly volunteers. Fifty-one elders were randomly assigned to consume either a synbiotic dietary supplement or a placebo in addition to their usual diet for a 2-week period. The synbiotic product consisted of the probiotic Lactobacillus acidophilus NCFM and the prebiotic lactitol and was ingested twice a day, with a total daily dose of 10 g lactitol and 2 × 10(10) cells of probiotic bacteria. Before, during and after the intervention period fecal quantities of six phylogenetic bacterial groups were determined using quantitative PCR, and relative changes in total microbiota composition were assessed by percent guanine-plus-cytosine profiling. The microbiota profiles showed certain relative changes within the microbial community, and indicated an increase of bifidobacteria levels during synbiotic supplementation. Quantification by PCR confirmed the in changes in the microbiota composition; for example increases in total levels of endogenous bifidobacteria and lactobacilli were recorded. Throughout the 6-week study period there was a decrease unrelated to intervention in the Blautia coccoides-Eubacterium rectale bacterial group levels and Clostridium cluster XIVab levels, but this decrease appeared to be halted during the synbiotic intervention. In conclusion, putatively beneficial changes in microbiota were observed in the elderly subjects supplemented with the synbiotic product.

Fig. 1

Percent G+C profiles of the bacterial community in fecal samples from the a placebo and b synbiotic groups. The lines in each graph indicate the mean relative abundance of all individual samples. Data were obtained as a continuous stream from the UV absorbance flow cell and are presented as % G+C content versus relative abundance

Fig. 2

Percent G+C profiles of the bacterial community in fecal samples from the a run-in time-point, b intervention time-point and c wash-out time-point. For detailed description, see Fig. 1

Fig. 3

P values from a ANOVA F-test and b, c contrast test for the original data in the relative abundance of % G+C profiles associated with a treatment, time-point, and treatment–time-point for both groups, and difference between separate time-points in the b placebo and c synbiotic group, analyzed using a sliding window model. Clear significant differences in the % G+C relative abundances are observed irrespective of the treatment allocation and also within the treatment groups at specific time-points. Differences between the run-in and intervention time-points within the synbiotic group reach statistical significance (P < 0.05) at 41% and under, 44–53%, and 62% G+C range and above