An interventional study of Fennel infusion in Colic, Infantile, sponsored by IITAA, Universidade dos Açores. Completed at 2 sites in Portugal. Open to participants aged 1 Month to 5 Months. Per ClinicalTrials.gov, last updated 2025-11-19.
Sponsored by IITAA, Universidade dos Açores · Not applicable, Interventional, and Basic science
The goal of this clinical trial is to determine whether a fennel-water infusion taken by mothers reduces colic in breastfed infants. The study will also assess the effect of the fennel infusion on the mothers' milk and the gut microbiota of the infants. The main questions it aims to answer are:
Participants-mothers of infants-will:
The project will investigate the effect of maternal ingestion of fennel infusion and the associated microbial changes in milk and the infant gut. A beneficial effect has been reported by mothers as part of popular medicine, but this has not been studied in controlled trials.
The trial aims to elucidate the mechanisms by which fennel compounds exert a colic-reducing effect in babies via breast milk. The investigators will determine whether an orally administered fennel seed infusion affects monitored symptoms or microbial parameters, and whether the composition of the fecal microbiota differs between colicky and non-colicky infants. Mothers will be asked to drink an infusion of fennel seeds (Foeniculum vulgare var. dulce) (20 g/L, 1 L per day) for one week. Samples of milk and feces will be collected at the beginning of treatment (day 0) and at the end of treatment (day 7) for microbiome analysis.
Samples will be prepared for Illumina sequencing by 16S rRNA gene amplification of the bacterial community. Raw reads will be extracted from the Illumina MiSeq System in fastq format and processed in the QIIME2 package using DADA2 to infer amplicon sequence variants (ASVs) and their relative abundances across samples. Taxonomy will be assigned to ASVs with the q2 feature-classifier using a pre-trained Naïve Bayes classifier of the Silva database. For species assignment, sequences will be further analyzed using the GenBank DNA database with the Basic Local Alignment Search Tool (BLAST) algorithm.
Alpha diversity will be determined using the number of taxa, individuals - amplicon sequence variants (ASVs), dominance (1-Simpson index), Margalef's richness index, evenness, and Chao1. Alpha diversity results will be compared before and after the intervention using the Wilcoxon signed-rank test. Beta diversity will be measured using principal coordinate analysis (PCoA) based on Bray-Curtis distance matrices for ASVs and PERMANOVA. The Wilcoxon signed-rank test will be used to compare normalized ASVs at the genus and species levels before the intervention (day 0) and after (day 7).
127 studies on the registry are indexed under Colic; 18 are open to participants now.
This study's enrollment of 22 is below the median of 76 across 110 interventional studies indexed under Colic.
Browse Colic studies →This is the only study on the registry with IITAA, Universidade dos Açores as lead sponsor.
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Exclusion Criteria:
Breastfeeding women and their infants
Dietary Supplement: Fennel infusion
The mothers were asked to drink an infusion of fennel seeds (1 L per day) for one week .
Proportion of participants with a ≥50% reduction in daily crying duration as measured by a parent-reported 24-hour diary.
Response is defined as a reduction of at least 50% from baseline in mean daily crying duration. The baseline value is the mean daily crying duration recorded by parents in a 24-hour diary for the two days before treatment initiation, as reported in a questionnaire. The post-treatment value is the mean daily crying duration recorded in the 24-hour diary on the final two days of the one-week treatment period.
Time frame: One week
Changes in bacterial community of infant stool samples
The bacterial community, assessed by changes in biodiversity indices and the relative proportions of bacterial genera in infant stool samples, will be evaluated before the intervention (day 0) and at the end of the trial (day 7).
Time frame: One week
Changes in bacterial community of breast milk
The bacterial community, assessed by changes in biodiversity indices and the relative proportions of bacterial genera in breast milk samples, will be evaluated before the intervention (day 0) and at the end of the trial (day 7).
Time frame: One week
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No — IPD used in the results publication.
Ran from Sep 2021 to primary completion in Apr 2024, 31 months.
Of 32 non-industry interventional studies with no phase under Colic, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 40. This study's 31 months is above that.
Counting every sponsor, half of 44 studies reached it within 21 months; a quarter within 10 and three quarters within 40.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
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