The design of this study conforms to a randomized double-blind placebo-controlled cross-over
The objective of the study is to assess the effect of three probiotics (Lactobacillus
plantarum WCFS1, Lactobacillus plantarum CIP104448, and Lactobacillus plantarum CIP104450) on
intestinal epithelial permeability and the immune system, in at least 8 healthy subject.
The effect of the three different probiotics and a placebo will be assessed on every subject
in random sequence.
Prior to the start of a 7-days supplementation period (one of the three probiotic supplements
or placebo), blood samples will be obtained and small intestinal permeability will be
assessed by measuring the urinary extraction ratios of ingested water-soluble, non-degradable
test probes, with and without indomethacin challenge (to compromise the gut). After each
supplementation period the gut will be stressed again by the indomethacin protocol, followed
by measurement of small intestinal permeability, whereupon blood samples will be taken and
duodenal tissue samples will be obtained by standard gastroduodenoscopy. Each supplementation
period will start 1 month after finishing the pervious test episode, in randomized sequence.
The primary objective of this study is to assess the effects of Lactobacillus plantarum
WCFS1, Lactobacillus plantarum CIP104448, and Lactobacillus plantarum CIP104450 on intestinal
epithelial permeability. Secondary objectives are to assess the effects on immune modulation,
gene expression of peripheral blood mononuclear cells, small intestine epithelial gene
regulation and tight junction proteins modulation, infiltration of immune cells in intestinal
mucosa and immune markers in blood plasma.
The investigators hypothesize that Lactobacillus plantarum WCFS1, Lactobacillus plantarum
CIP104448, and Lactobacillus plantarum CIP104450 will, each separately, significantly affect
the innate immune system and intestinal permeability in humans.