The aim of the study is to examine the intervening effects of N1115 Probiotic Supplement (containing Junlebao Lp. N1115) on gut development in young children at the age of 6 month to 3 years by the way of a randomised, double-blinded, parallel, placebo-controlled clinical trial, and to explore the change of intestinal microbiota composition and healthy condition after intervention.

N1115 Probiotic Supplement contains Lactobacillus paracasei N1115 [Junlebao Lp. N1115], a lactobacillus bacteria strain isolated from traditional homemade yogurt in North China. In recent studys feeding Junlebao Lp. N1115 to C57BL/6 mice, the data suggest that Lp. N1115 enhances intestinal development in neonatal mice, and may confer benefits on the growth at early stage of life.

This study is to investigate if a N1115 Probiotic Supplement product containing Lp. N1115 will improve intestinal health in young children. This randomised, double-blinded, placebo-controlled trial includes two treatment groups which respectively need to recruit 30 volunteers born by cesarean section and aged from 6 months to 3 years. The study group receives N1115 Probiotic Supplement, while the control group receives placebo. The trial lasts for 8 weeks and include four time points of data collection. The stool consistency of children will be recorded everyday, the saliva and stool samples will be collected and analysed.

Inclusion Criteria:

1. Male or female subjects aged ≥ 6 months and ≤ 3 years,
2. Child was born by caesarean section,
3. Parent/Guardian has given written informed consent,
4. Be in generally good health as determined by the investigator.

Exclusion Criteria:

1. Are currently taking probiotics or prebiotics, or have taken them in the past 2 weeks,
2. Unwilling to avoid probiotics/prebiotics for the duration of the study,
3. Has any food allergies or an allergy or hypersensitivity to any component of the study products, including, milk proteins allergy or cow's milk allergy,
4. Have a significant acute or chronic coexisting illness (cardiovascular, gastrointestinal, endocrinological, immunological, metabolic or any condition which contraindicates, in the investigators judgement, entry to the study),
5. Having a condition or taking a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results,
6. Subjects have taken antibiotics within the past 3 months (history of antibiotic use in previous 6 months recorded),
7. Subjects may not be receiving treatment involving experimental drugs,
8. If the subject has been in a recent experimental trial, these must have been completed not less than 60 days prior to this study.
9. Subjects may not be receiving treatment involving experimental drugs,
10. Exposure to any non-registered drug product within 30 days prior to screening visit.