Probiotic modulation of gut microbiota by Bacillus coagulans MTCC 5856 in healthy subjects: A randomized, double-blind, placebo-control study

Abstract

Background: Probiotics are known to rebalance the gut microbiota in dysbiotic individuals, but their impact on the gut microbiome of healthy individuals is seldom studied. The current study is designed to assess the impact and safety of Bacillus coagulans (Weizmannia coagulans) microbial type culture collection 5856 (LactoSpore®) supplementation on microbiota composition in healthy Indian adults.

Methods: The study participants (N = 30) received either LactoSpore (2 billion colony-forming units/capsule) or placebo for 28 days. The general and digestive health were assessed through questionnaires and safety by monitoring adverse events. Taxonomic profiling of the fecal samples was carried out by 16S rRNA amplicon sequencing using the Illumina MiSeq platform. The bacterial persistence was enumerated by quantitative reverse transcription-polymerase chain reaction.

Results: Gut health, general health, and blood biochemical parameters remained normal in all the participants. No adverse events were reported during the study. Metataxonomic analysis revealed minimal changes to the gut microbiome of otherwise healthy subjects and balance of Bacteroidetes and Firmicutes was maintained by LactoSpore. The relative abundance of beneficial bacteria like Prevotella, Faecalibacterium, Blautia, Megasphaera, and Ruminococcus showed an increase in probiotic-supplemented individuals. The quantitative polymerase chain reaction analysis revealed highly variable numbers of B. coagulans in feces before and after the study.

Conclusion: The present study results suggest that LactoSpore is safe for consumption and does not alter the gut microbiome of healthy individuals. Minor changes in a few bacterial species may have a beneficial outcome in healthy individuals. The results reiterate the safety of B. coagulans microbial type culture collection 5856 as a dietary supplement and provide a rationale to explore its effect on gut microbiome composition in individuals with dysbiosis.

Figure 1.

Consort diagram – flowchart of study procedures, from eligible 30 subjects who fit into inclusion and exclusion criteria, 26 subjects completed the study. At every follow-up visit, study evaluations were made in both study groups.

Figure 2.

(A) Rarefaction plot for 52 samples of V3 to V4 region at a depth of 24,000. The image was plotted against the number of sequences per sample on the X-axis versus diversity index on Y-axis. The samples are colored by their respective names. As the sequencing depth increased, the number of observed species (OTUs) also increased. Eventually, the curves began to plateau, indicating that as the number of extracted sequences increased, the number of OTUs detected decreased; Box plot representing alpha diversity measured by (B) Shannon, (C) Chao1, (D) Simpson for the Placebo and Active. The line inside the box represents the median, while the whiskers represent the lowest and highest values within the 1.5 interquartile range (IQR); (E and F) The dots represent outliers principal coordinate analysis (PCoA) plots of the active (n = 12), versus placebo group (n = 14) specific taxa with significant (P < .05). PCoA plots of (E) weighted and (F) unweighted Unifrac distance matrices. Axis title indicates percentage variation. OTUs = operational taxonomic units.

Figure 3.

The relative abundance of the bacterial phyla (A) placebo baseline visit; (B) placebo final visit; (C) active baseline and (D) active final visit.

Figure 4.

Bar plot showing microbial composition of active and placebo group at baseline and final visit at genus level with its corresponding relative percentages.

Figure 5.

Relative abundance of bacterial genus (A) Bacteroides; (B) Bifidobacterium; (C) Faecalibacterium; (D) Prevotella; (E) Mitsuokella; (F) Lachnospira; (G) Ruminococcus; (H) Roseburia; (I) Blautia; (J) Megasphaeara in active and placebo groups at baseline and final visit. Values expressed as mean ± SEM.

Figure 6.

Enumeration of Bacillus coagulans by quantitative real-time PCR showed that fecal samples from the active group showed an increase in B. coagulans cell count compared to that of the placebo group. PCR = polymerase chain reaction.

Figure 7.

Abdominal Health Questionnaire Assessment analysis.