Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul 30:12:1566376.
doi: 10.3389/fnut.2025.1566376. eCollection 2025.

The influence of human milk composition and its microbiome on the gut microecology and early growth and development of preterm infants (the YI study): protocol design and cohort profile

Xinyue Wang #  1 , Yan Feng #  2 , Yilan Li  1 , Yuluyuan Tian  1 , Simin Zhang  1 , Jinglin Li  1 , Jiahui Zhang  1 , Feng Liu  1 , Jiahe Zhou  1 , Ting Li  3   4 , Sufang Duan  3 , Ignatius Man-Yau Szeto  3   5 , Li Su  2 , Xiaoqin Luo  1   6
Affiliations

The influence of human milk composition and its microbiome on the gut microecology and early growth and development of preterm infants (the YI study): protocol design and cohort profile

Xinyue Wang et al. Front Nutr. .

Abstract

Introduction: Breastfeeding can reduce the risk of serious illness in preterm infants. However, the influence of human milk on the gut microecology and early development of preterm infants remains unclear.

Methods: The YI Study is a prospective cohort protocol conducted in China, designed to investigate the dynamic associations among breast milk composition, infant gut microecology, and health from a mother-breastmilk-preterm infant triad perspective. From January 2023 to May 2024, a total of 50 mother-term infant dyads and 35 mother-preterm infant dyads were enrolled and followed up at six timepoints: v1 (0-7 days), v2 (8-14 days), v3 (1 month), v4 (2 months), v5 (4 months), and v6 (6 months). Data collection included questionnaires, anthropometric measurements, and biospecimens. Questionnaires (including birth medical records, environment, feeding practices and illnesses status) and anthropometric measurements were collected at all visits. Biospecimens included paired samples of breast milk and feces were obtained at each visit, and comprehensively analyzed by multi-omics techniques. We also collected heel blood at birth to examine immune status and saliva at the v6 visit to explore the role of its constituents in dietary behaviors.

Results: The average age of the mothers was 30.9 ± 3.5 years. The median gestational age was 36 (35, 36) weeks in the Preterm Group and 39 (38, 40) weeks in the Term group. The completion rate up to V6 was 82.9% in the Preterm Group and 94% in the Term Group. All samples were collected within the predefined visit windows, with a total of 452 breast milk, 465 infant feces, 227 maternal feces, 49 heel blood and 98 saliva.

Discussion: Through ultra-early, multi-temporal, multi-sample collection, combined with multi-omics technologies, the YI study will provide an opportunity to explore the dynamic association of human milk as a complex biological system with gut microecology and health in preterm infants in depth.

Keywords: early life health; gut microecology; human milk; preterm infants; systems biology.

PubMed Disclaimer

Conflict of interest statement

TL, SD, and IS were employed by Inner Mongolia Yili Industrial Group Co., Ltd. TL was employed by Inner Mongolia Dairy Technology Research Institute Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Visualization chart for YI study aims. Created with BioRender.com.
Figure 2
Figure 2
The principle for cohort establishment and time points for dyads data and sample collection. Created with BioRender.com.
Figure 3
Figure 3
Flow chart of participants missed visit, defined as a follow-up visit that was skipped due to the participants left the place of the follow-up visit, but still attended the subsequent follow-up visits. Withdraw, means that participants completely quit the study.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Healy DB, Ryan CA, Ross RP, Stanton C, Dempsey EM. Clinical implications of preterm infant gut microbiome development. Nat Microbiol. (2021) 7:22–33. doi: 10.1038/s41564-021-01025-4, PMID: - DOI - PubMed
    1. Escalante KS, Bai-Tong SS, Allard SM, Ecklu-Mensah G, Sanchez C, Song SJ, et al. The impact of breastfeeding on the preterm infant’s microbiome and metabolome: a pilot study. Pediatr Res. (2025) 97:1227–1236. doi: 10.1038/s41390-024-03440-9, PMID: - DOI - PMC - PubMed
    1. Miller J, Tonkin E, Damarell RA, McPhee AJ, Suganuma M, Suganuma H, et al. A systematic review and meta-analysis of human milk feeding and morbidity in very low birth weight infants. Nutrients. (2018) 10:707. doi: 10.3390/nu10060707, PMID: - DOI - PMC - PubMed
    1. Balcells-Esponera C, Borràs-Novell C, López-Abad M, Serra IC, Puig AB, Renau MI, et al. Bioactive peptides in preterm human milk: impact of maternal characteristics and their association to neonatal outcomes. Biofactors. (2023) 50:135–44. doi: 10.1002/biof.1997, PMID: - DOI - PubMed
    1. Altobelli E, Angeletti PM, Verrotti A, Petrocelli R. The impact of human Milk on necrotizing enterocolitis: A systematic review and Meta-analysis. Nutrients. (2020) 12:1322. doi: 10.3390/nu12051322, PMID: - DOI - PMC - PubMed

LinkOut - more resources