Abstract
Objectives
This exploratory study builds upon an earlier study of probiotic supplementation1 to assess the effects of a probiotic combination (P) of LGG and BB-12 on human gut microbiota composition and function, and to uncover an association with BMI.
Methods
Healthy subjects ingested P for 21 days (n = 18, P group) or did not (n = 7, C group).
Fecal samples obtained at baseline (D_0) and after 21 days of supplementation (D_21) underwent 16S ribosomal RNA gene and shotgun metagenomics sequencing to characterize the bacterial and archaeal communities to the genus/species level and identify functional community genes.
Results
Following P ingestion, no global differences in microbiota community structure or relative gene abundance were detected. In targeted analyses, the abundances of LGG and BB-12 in the P group at D_21 increased in a statistically significant manner as the BMI decreased (Spearman correlation, P = 0.04 and P = 0.01, respectively). The relative abundance of LGG but not BB-12 appeared increased in P subjects at D_21 with BMI < 25 compared to BMI > 25 (P = 0.09). P group subjects with BMI < 25 demonstrated trends toward or statistically significant increases in the relative abundances of 5 genes involved with flagellar structure (KEGG orthologs K02422, P = 0.04; K03406, P = 0.06; K02407, P = 0.08; K02397, P = 0.08; K02396, P = 0.09) at D_21 compared to those with BMI > 25. No such differences were observed for the C group nor were there differences in relative gene abundance at D_0 in the P group with BMI < 25 vs BMI > 25.
Conclusions
We observed no global changes in the fecal microbial community structure or function with P ingestion in this sample of healthy persons. However, we did observe patterns suggestive of a potential link between BMI and the response of the gut microbiota to P. Although our results are based on a small number of subjects, they are in line with previous findings related to LGG supplementation and the expression of flagellar genes2. We agree with other recent reports that future studies would benefit from a detailed examination of the transcriptome, proteome and/or metabolome to better understand the potential impact of probiotics on the gut microbiota, and the mechanism of the effect of BMI.
Funding Sources
Pfizer Inc.
Effect of nitrogen and waterlogging on denitrifier gene abundance, community structure and activity in the rhizosphere of wheat
