Effect of Bifidobacterium longum subsp. Infantis YLGB-1496 on Common Pediatric Conditions: A Randomized, Blinded, Placebo-Controlled Trial

Xi Zhang¹Ke Chen^2*Hanglian Lan³Haixia Chen⁴Hua Chen⁴Ping Yang⁵Nianyang He⁵Weilian Hung³Zaozhong Zeng³Changqi Liu⁶

• ¹Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China,, Sichuan Chengdu, China
• ²Department of Nutrition, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, chengdu, China
• ³National Center of Technology Innovation for Dairy, baoding, China
• ⁴Baoxing Center for Disease Control and Prevention, baoxing, China
• ⁵Department of Child Health Care, Xindu Maternal and Child Health Care Hospital, chengdu, China
• ⁶School of Exercise and Nutritional Sciences, San Diego State University, United States of America, San Diego, Micronesia

Introduction: Respiratory, gastrointestinal, and allergic diseases can significantly impact both the physical and mental health of children, affecting their overall quality of life. This study aimed to evaluate the preventive effects and safety of Bifidobacterium longum subsp. infantis YLGB-1496 in relation to respiratory, gastrointestinal, and allergic diseases in children.Eligible healthy children were randomly assigned to either an intervention group (IG, n= 50), which received the probiotic, or a control group (CG, n= 50), which received a placebo, for a duration of three months. The primary outcome was the morbidity of upper respiratory tract infections (URTIs).Gut microbiota profiles were assessed via fecal 16S rRNA sequencing. Fecal immune biomarkers, including cytokines, immunoglobulins, and short-chain fatty acids (SCFAs), were measured to evaluate immune and metabolic responses. Results: The morbidity of URTIs[1] over the 6-month 3-month intervention and follow-up period was significantly lower in the IG than in the CG. The incidence of upper respiratory tract infections (URTIs) over the 6-month 3-month intervention and follow-up period was significantly lower in the IG than in the CG, based on intention-to-treat (ITT) analsysis [34.0% (17/50) vs.58.0% (29/50), χ 2 =5.797, p=0.016]. Per protocol (PP) analyses yielded similar results [36.2% (17/47) vs. 60.4% (29/48), χ 2 =5.59, p=0.018]. YLGB-1496 supplementation significantly increased the abundance relative abundance of Bifidobacterium bifidum, Bifidobacterium kashiwanohense PV2, and Bifidobacterium longum, while reducing Bacteroides thetaiotaomicron levels in the IG compared to the CG (p< 0.05). Additionally, YLGB-1496 reduced fecal levels of pro-inflammatory factors (IL-1β and IFNγ) levels, and increased levels of immunoglobulin (IgA, IgG and IgM) and SCFAs (including butyric acid and total SCFAs).Daily administration of YLGB-1496 at a dosage of 1.5×10 10 CFU for three months significantly reduced the episodes of cough, fever, dry stool (defined as Bristol stool scale type 1-3), and eczematous changes of the skin. It also decreased the morbidity of URTIs, bronchopneumonia, and eczema, while beneficially modulating gut microbiome composition and immune function without any adverse effects.