Effect of supplement containing Lactococcus lactis subsp. cremoris FC on defecation in healthy humans: A randomized, placebo-controlled, double-blind crossover trial

Objectives The aim of this study was to evaluate the effect of Lactococcus lactis subsp. cremoris FC on fecal properties and fecal microflora in healthy subjects prone to constipation. Methods In total, 50 volunteers (seven men and 43 women) were randomized into two groups and given 100 mg of L. lactis subsp. cremoris FC (test) or dextrin (placebo) daily for 2 weeks in a double-blind, placebo-controlled, cross-over study. The fecal microflora was analyzed using the DNA extracted from feces and a real-time polymerase chain reaction. Results Compared with the ingestion of placebo, the defecation frequency significantly increased (days/week, P<0.05; times/week, P< 0.001) with the ingestion of L. lactis subsp. cremoris FC. The total bacterial count (log) and Lactobacillus sp. bacterial count (log) significantly (P<0.05) increased 2 weeks after the ingestion of test. Conclusion These results suggest that the continuous ingestion of L. lactis subsp. cremoris FC caused changes in intestinal microflora, improving defecation status and fecal characteristics in healthy subjects prone to constipation.