Immune System Stimulation by Probiotic Food Supplementation

Hangzhou Wei Chuan Foods Co., Ltd.136 enrolled

Overview

The purpose of this study is to investigate the effects of a probiotic supplementation on adult volunteers with having caught the common cold more than 4 times in the past year. This study is a single center, double-blind, randomized, controlled, parallel-designed, prospective trial. Subjects received a probiotic drink containing probiotics of Lactobacillus paracasei (108 colony forming units (CFU)/ml), Lactobacilluscasei431® (108CFU/ml) and Lactobacillus fermentiumPCC® (106CFU/ml) or an identical placebo without probiotics for a 12-week study period. The incidence of flue and cold during the study period were compared between study groups. Blood and fecal samples were collected at baseline and at the end of the intervention. Fecal samples were collected for the secretory immunoglobulin A (sIgA) analysis. Blood sample was drawn for interferon γ (IFN-γ), interleukin 4 (IL-4), interleukin 10 (IL-10), immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM) analysis.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Enrollment

136

Conditions

Flu Symptom

Interventions

Eligibility

Sex: ALLMin age: 25 YearsMax age: 45 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * male or female between 25 to 45 years old; * having caught the common cold or flu at least 4 to 6 times in the past calendar year; * signed the informed consent forms before entering the study; * fully understood the risks and potential benefits in participating this study. Exclusion Criteria: * were diagnosed with the decreased immunity caused by any diagnosed chronic illness; * having any gastrointestinal illness with medical treatment at the time of being enrolled; * having any diagnosed respiratory illness with similar symptoms as the common cold and flu; * currently taking any pain killer drug; * having received any vaccine for the upper respiratory infection within 6 months before enrollment; * having received any purgative drug or digestion related drug within 2 weeks before enrollment; * having taken any dairy product containing prebiotics and probiotics within 10 days before enrollment; * currently taking any preventive drug for upper respiratory infection; * having received any drug which has impact with the immune system such as antibiotics within 3 months before enrollment; * alcoholic or addicted to any drug; * pregnant or breastfeeding mothers; * having participated another clinical trial within 3 months before enrollment.

Outcomes

Primary Outcomes

Incidence of flue symptoms during the study

Body temperature≥38.0℃, and have one or more symptoms of cough, runny nose, throat pain, headache, muscle pain, weak feeling, hard to breath, chest pain or loss of appetite.

Time frame: end of week 12

Secondary Outcomes

Incidence of cold symptoms during the study

Body temperature\<38.0℃, and have one or more symptoms of cough, runny nose, throat pain, headache, muscle pain, weak feeling, hard to breath, chest pain or loss of appetite.

Time frame: end of week 12

Number of accumulated days of having cold symptoms during the study

The total number of days of having one or more symptoms of cough, runny nose, throat pain, headache, muscle pain, weak feeling, hard to breath, chest pain or loss of appetite during the 12 week study period.

Time frame: End of week 12

Serum IFN-γ concentration

Interferon gamma (unit: pg/ml)