Synbiotic Intervention with Lactobacilli, Bifidobacteria, and Inulin in Healthy Volunteers Increases the Abundance of Bifidobacteria but Does Not Alter Microbial Diversity.

2022-10-11
Applied and environmental microbiology 88(19)

PubMed: 36165644
DOI: 10.1128/aem.01087-22

Study Design

Type: Clinical Trial
Sample size: n = 12
Population: 15 healthy volunteers
Methods: single-group-design trial; synbiotic intervention comprising Lacticaseibacillus rhamnosus (LGG), Lactobacillus acidophilus (LA-5), Lacticaseibacillus paracasei subsp. paracasei (L. CASEI 431), and Bifidobacterium animalis subsp. lactis BB-12 and 20 g of chicory-derived inulin powder consumed daily for 4 weeks; fecal samples were collected at baseline and at completion of the intervention

Rigorous Journal

Synbiotics combine probiotics and prebiotics and are being investigated for potential health benefits. In this single-group-design trial, we analyzed changes in the gut microbiome, stool quality, and gastrointestinal well-being in 15 healthy volunteers after a synbiotic intervention comprising Lacticaseibacillus rhamnosus (LGG), Lactobacillus acidophilus (LA-5), Lacticaseibacillus paracasei subsp. paracasei (L. CASEI 431), and Bifidobacterium animalis subsp. lactis BB-12 and 20 g of chicory-derived inulin powder consumed daily for 4 weeks. Fecal samples were collected at baseline and at completion of the intervention, and all participants completed a fecal diary based on the Bristol Stool Scale and recorded their gastrointestinal well-being. No adverse effects were observed after consumption of the synbiotic product, and stool consistency and frequency remained almost unchanged during the trial. Microbiome analysis of the fecal samples was achieved using shotgun sequencing followed by taxonomic profiling. No changes in alpha and beta diversity were seen after the intervention. Greater relative abundances of Bifidobacteriaceae were observed in 12 subjects, with indigenous bifidobacteria species constituting the main increase. All four probiotic organisms increased in abundance, and L. rhamnosus, B. animalis, and L. acidophilus were differentially abundant, compared to baseline. Comparison of the fecal strains to the B. animalis subsp. lactis BB-12 reference genome and the sequenced symbiotic product revealed only a few single-nucleotide polymorphisms differentiating the probiotic B. animalis subsp. lactis BB-12 from the fecal strains identified, indicating that this probiotic strain was detectable after the intervention. IMPORTANCE The effects of probiotics/synbiotics are seldom investigated in healthy volunteers; therefore, this study is important, especially considering the safety aspects of multiple probiotics together with prebiotic fiber in consumption by humans. The study explores at the potential of a synbiotic intervention with lactobacilli, bifidobacteria, and inulin in healthy volunteers and tracks the ingested probiotic strain B. animalis subsp. lactis.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Bifidobacterium lactis DSM 15954	—	Increased Fecal Probiotic Strains	Beneficial	Small	View source All four probiotic organisms increased in abundance, and L. rhamnosus, B. animalis, and L. acidophilus were differentially abundant, compared to baseline... indicating that this probiotic strain was detectable after the intervention.
Bifidobacterium lactis DSM 15954	—	No Change in Microbial Diversity	Neutral	Small	View source No changes in alpha and beta diversity were seen after the intervention.
Bifidobacterium lactis DSM 15954	—	Unchanged Stool Consistency or Bowel Frequency	Neutral	Small	View source No adverse effects were observed after consumption of the synbiotic product, and stool consistency and frequency remained almost unchanged during the trial.