Effect of probiotics on the intestinal microbiota of healthy adults

• Register: ISRCTN
• Last refreshed on: 17 October 2016
• Main ID: ISRCTN56945491
• Date of registration: 29/07/2014
• Prospective Registration: No
• Primary sponsor: DeFENS - Division of Food Microbiology and Bioprocessing (Italy)
• Public title: Effect of probiotics on the intestinal microbiota of healthy adults
• Scientific title: Effect of the consumption of probiotic microorganisms on the composition and activity of the fecal microbiota of healthy adults
• Date of first enrolment: 01/02/2013
• Target sample size: 20
• Recruitment status: Completed
• URL: http://isrctn.com/ISRCTN56945491
• Study type: Interventional
• Study design: Randomized double-blind placebo-controlled crossover study (Other)
• Phase: Not Applicable

Countries of recruitment

Italy

Contacts

• Name: Simone Guglielmetti

Key inclusion & exclusion criteria

Inclusion criteria: 1. Healthy male or female subjects, aged between 18 and 55 years
2. Signed study-specific informed consent
Exclusion criteria: 1. Antibiotic therapy during one month before the first visit
2. Viral or bacterial enteritis during the two months before the first visit
3. Gastric or duodenal ulcers during the five years before the first visit
4. Pregnant or breastfeeding women
5. Recent or presumed episodes of alcoholism or drug addiction
6. Presence of conditions determining a non-conformity of the volunteer to the study protocol

Age minimum:
Age maximum:
Gender: Both

Health Condition(s) or Problem(s) studied

N/A
Not Applicable

Intervention(s)

Current interventions as of 30/10/2015:
The trial consists of four phases:
1. Pretreatment (4 weeks)
2. First treatment (4 weeks)
3. Washout (4 weeks)
4. Second treatment (4 weeks)

The trial includes five visits per participant:
1. Before pretreatment (visit V0)
2. Before the first treatment (i.e. after the pretreatment) (V1)
3. After the first treatment (i.e. before the washout) (V2)
4. Before the second treatment (i.e. after the washout) (V3)
5. After the second treatment (V4).

During a pre-recruitment phase (4 weeks), volunteers will follow their conventional diet with the only prohibition to consume: probiotic fermented milk (traditional yogurt is allowed), probiotic food formulas, foods enriched in prebiotic molecules, prebiotic food formulas. At the end of the pre-recruitment stage, volunteers will be randomized to receive to receive the one probiotic formulation or placebo for 4 weeks. Probiotic formulations are two: (i) Enterolactis® Plus constituted by capsules containing at least 24 billion CFU (colony forming units) of freeze-dried Lactobacillus paracasei DG; (ii) Bb probiotic, constituted by capsules containing at least 1 billion CFU (colony forming units) of freeze-dried Bifidobacterium bifidum Bb. The placebo will be constituted by capsules with identical dimensions, color and taste to the probiotic product. The capsules will be consumed with water in the morning (preferably) at least 10 minutes before breakfast or in the evening at least 2 hours after the last meal of the day. After the 4-week treatment, a 4-week wash-out period will follow. After the wash-out, volunteers will receive the probiotic or placebo capsules for 4 weeks, according to the cross-over design.

One fecal sample is collected from each participant at V1, V2, V3, and V4. Every fecal samples is prepared for analysis of the microbiota and the quantification of microbial metabolites. Specifically, the microbiota of fecal samples will be characterized by Ion Torrent PGM sequencing o

Primary Outcome(s)

Assessment of the ability of the probiotic to modify the fecal microbiota in healthy adults (as determined by 16S rRNA gene metagenomic profiling). All outcomes are assessed at V1, V2, V3, and V4.

Secondary Outcome(s)

1. Change in bowel habit
2. Change in fecal metabolite concentration (e.g., short chain fatty acids, bile salts)
3. Persistence of probiotic microorganism in the intestine of volunteers
All outcomes are assessed at V1, V2, V3, and V4.

Secondary ID(s)

N/A

Source(s) of Monetary Support

The Cariplo Foundation (Italy), research grant 2010-0678, Università degli Studi di Milano (Italy), Sofar S.p.A (Italy)