Condition category
Not Applicable
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Different types and quality of dietary protein can affect the absorption of essential nutrients (amino acids) following protein supplementation. Compared to animal protein sources, plant protein sources, with the exception of soy protein, are incomplete proteins lacking in one or more essential amino acids. Through optimizing gut bacteria (microbiota) composition, certain strains of live bacteria (probiotics) have been linked to improved nutrient absorption, including protein utilization. Different types and quality of dietary protein can affect amino acid absorption following protein supplementation. Compared to animal protein sources such as pea are incomplete proteins lacking in one essential amino acid. In addition, plant proteins contain less branched-chain amino acids (BCAAs), especially leucine, one of the crucial amino acids for muscle health, especially the activation of muscle protein synthesis. Plant proteins differ in absorption kinetics and the amount of amino acids absorbed by the host. Therefore, there is an interest in nutritional strategies to improve or raise the blood amino acid concentrations after ingesting a plant protein source to overcome compositional shortcomings. The purpose of this study is to investigate the effect of probiotic supplementation on amino acid absorption of plant proteins.

Who can participate?
Healthy men between the ages of 18–35 years, with normal body weight, who are recreationally active.

What does the study involve?
Participants are randomly allocated to receive a supplement containing vegetable protein and probiotic bacteria or vegetable protein alone for two weeks. After a four week period the participants will take the opposite supplement for two weeks.

What are the possible benefits and risks of participating?
The results of this study can be utilized to develop an effective probiotic supplement that could be used to enhance the appearance of amino acids in the blood and potentially recovery from exercise and sport participation, or reduce age-related muscle loss.
Risks of the blood sampling procedure include bruising, hematoma, dizziness, fainting, pain upon needle stick, and the remote risk of infection. These risks will be minimized by having trained personnel obtain blood samples using standard procedures and, sterile, single use phlebotomy supplies.

Where is the study run from?
1. Texas Christian University, USA
2. University of Mary Hardin-Baylor, USA

When is the study starting and how long is it expected to run for?
August 2017 to October 2019

Who is funding the study?
1. Sofar S.p.A., Italy
2. Increnovo LLC, USA

Who is the main contact?
Dr Ralf Jäger

Trial website

Contact information



Primary contact

Dr Ralf Jäger


Contact details

2138 E Lafayette Pl
United States of America
+1 414-226-0026

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

The effect of L. paracasei LP-DG® (CNCM I-1572) and L. paracasei LPC-S01 (DSM 26760) administration on amino acid absorption from plant protein – A placebo-controlled, randomized, double-blind, multicenter, crossover study


Study hypothesis

Growing transition to more plant-based, whole-foods, sustainable diets raised questions about the protein adequacy of vegetarian and vegan diets. In addition, a reduction of animal protein intake, in particular meat consumption, has recently become more prevalent in Western countries. Plant proteins differ in digestibility and amino acid composition from animal proteins. Specifically, plant proteins such as pea or rice are lower in leucine and total BCAA content, amino acids that have been linked to muscle health by activating muscle protein synthesis. Through optimizing gut microbiota composition, specific probiotic strains have been linked to improved nutrient absorption, including protein utilization. While lactic acid bacteria (LAB) have proteases and peptidases that provide the bacteria with free amino acids for optimal growth, they are not classified as strongly proteolytic bacteria. The role of LAB such as Lactobacillus paracasei on protein digestion and absorption of amino acids by the host is currently unknown.
Thus, the purpose of this study was to investigate the individual and potential additive or synergistic effects of L. paracasei LP-DG® and/or L. paracasei LPC-S01 on the in vitro digestion of different plant protein sources, in conjunction with a human study investigating blood amino acid concentrations after co-administration of plant protein and probiotics.

Ethics approval

1. Approved 31/07/2017, Institutional Review Board of Texas Christian University (Fort Worth, TX, USA; tel. not provided; email not provided), ref: 1707-080-1707
2, Approved 04/01/2019, The University of Mary Hardin-Baylor (Belton, Texas, USA; tel. not provided;, ref: Protocol #44

Study design

Interventional placebo-controlled randomized double-blind multicenter crossover study

Primary study design


Secondary study design

Randomised cross over trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Healthy individuals


Co-administration of 20 g of protein (vegetable protein isolated from yellow pea (Pisum Sativum), NUTRALYS® S85F, Roquette Freres S.A., France) with either 10 billion CFU of a multi-strain probiotic (5 billion CFU L. paracasei LP-DG® (CNCM I-1572) and 5 billion CFU L. paracasei LPC-S01 (DSM 26760), AminoAlta™, SOFAR S.p.A., Italy) or a placebo (maltodextrin, Glucidex® 12, Roquette Freres S.A., France).

The study consisted of a two week supplementation period, followed by a four week washout, followed by a crossover of groups and another two weeks of supplementation. As for the randomization process, we used to randomize everyone as they came into the lab. We assigned the A treatment as 1 and the B treatment as 2 and the website gave us a number for that person.

Intervention type



Drug names

Primary outcome measure

Plasma amino acid concentrations measured using tandem-mass spectrometry (LC/MS/MS) at baseline, 30, 60, 120, and 180 minutes post-ingestion

Secondary outcome measures

Adverse events throughout the study measured using case report forms

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Healthy men between the ages of 18–35 years
2. Normal body weight (body mass index (BMI) of 19 – 24.99 kg/m²)
3. Recreationally active (according to American College of Sports Medicine Guidelines)
4. Subjects were not allowed to consume any nutritional or ergogenic supplement known to affect measures of the current study for the prior six weeks, including probiotics, prebiotics and digestive enzymes

Participant type

Healthy volunteer

Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Currently being treated for or diagnosed with a gastrointestinal, cardiac, respiratory, circulatory, musculoskeletal, metabolic, immune, autoimmune, psychiatric, hematological, neurological or endocrinological disorder
2. Not weight stable defined as measured body mass deviating by 2% or more
3. Not willing to abstain from alcohol, nicotine, and caffeine for 12 hours prior to each visit

Recruitment start date


Recruitment end date



Countries of recruitment

United States of America

Trial participating centre

Texas Christian University
2800 S University Dr
Fort Worth
United States of America

Trial participating centre

University of Mary Hardin-Baylor
900 College St
United States of America

Sponsor information


Sofar (Italy)

Sponsor details

Via Firenze 40
Trezzano Rosa (MI)
+39 02909362 1

Sponsor type




Funder type


Funder name


Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Increnovo LLC

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal.

IPD sharing statement:
All data generated or analysed during this study will be included in the subsequent results publication

Intention to publish date


Participant level data


Basic results (scientific)

Publication list

2020 results in (added 15/10/2020)

Publication citations

Additional files

Editorial Notes

15/10/2020: The following changes were made to the trial record: 1. Publication reference added. 2. The total final enrolment was added.