This is a study to evaluate the prevalence of FGIDs in infants using the Thai version of Rome IV diagnostic questionnaire for functional gastrointestinal disorders in infants and evaluate the efficacy of Limosilactobacillus reuteri DSM 17938 to prevent FGIDs in infants.

This is a randomized controlled trial study about the the efficacy of Lactobacillus reuteri DSM 1987 to prevent FGIDs in healthy infants and the effect to gut microbiota diversity. The incidence of FGIDs in Thai infant using Thai version of ROME IV questionnaire (authorized by Rome Foundation) for infant and toddler and the associated factors of FGIDs also evaluate.

Population: target and control populations are the healthy infants born at King Chulalongkorn Memorial Hospital, Bangkok, Thailand, and can come to follow up at the hospital at 1, 2, 4, and 12 months of age Inclusion criteria

1. Healthy and term (GA 37-41 weeks) infants

2. Appropriate weight for age

3. APGAR score more than 8 at 10 minutes of life

4. Normal physical examination

5. Mothers have no previous probiotics use Methodology

   • Participants were double-blinded randomized using computer generation in block of four
   • Target population were received Limosilactobacillus reuteri DSM 17938 5 drops (0.185 mL) per day for 60 days
   • Control population were received mixture of sunflower oil and MCT oil 5 drop (0.185 mL) per day for 60 days
   • There were 5 visits at birth, 1, 2, 4, 12 months of life: the demographic data/Rome IV questionnaire for FGIDs in infant and associated factors with FGIDs record, physical examination and stool collection The study will be analyzed (open the randomized group) after all participants complete the 4-month follow-up period
   • Research assistance will telephone to them to take the Rome IV questionnaire for FGIDs at 3, 6, 9 months of life

Biological specimen collection Stool will be collected by rectal stimulation in each visit. The amount of >5 gm stool will be preserved in DNA and kept at -80 °C. All stool specimen will be processed the DNA extraction (DNA > 40 microlitre with concentration >50 ng/L). The DNA extraction for further amplification 16S rRNA using Illumina. The rest of the specimen will be kept up to 10 years for further evaluation.

Inclusion Criteria:

1. Healthy and term (GA 37-41 weeks) infants
2. Appropriate weight for age
3. APGAR score more than 8 at 10 minutes of life
4. Normal physical examination
5. Mothers have no previous probiotics use

Exclusion Criteria:

1. not willing to anticipate in the study
2. cannot come to follow-up until 1 year of age

The data were collected anonymous.

These 2 groups was assigned using computer generate with block of 4 and ratio 1:1.

The intervention and placebo were prepare in the same container with the same color, odor and blinded to investigators, participants and guardians.