Human milk oligosaccharides modulate inflammatory responses and lipid metabolism in a human intestinal organoid model

Human milk oligosaccharides (HMOs) are a major component of human breast milk and have significant protective effects on infant gut health. HMOs are also present in the amniotic fluid, exposing the fetal gut epithelium from 10 weeks of gestational age. Prior studies often relied on animal models or cell lines, which limited their relevance to human biology. In this study, we aimed to investigate the direct effect of a blend of HMOs, including 2'-fucosyllactose (2'FL), 3'-sialyllactose (3'SL), and difucosyllactose (DFL), on intestinal epithelial cells, exploring their role under steady-state conditions and during inflammation.

We utilized advanced human intestinal epithelial organoid (IEO) models from three fetal and three pediatric donors. Organoid viability and barrier function were assessed using functional assays. Bulk RNA sequencing was performed on a total of 76 samples to investigate transcriptomic responses to HMOs and interferon gamma (IFN-γ)-induced inflammation.

HMO treatment was safe and well-tolerated in both fetal and pediatric IEOs. The HMO blend reduced baseline BAX expression (p-value = 0.027) and attenuated the IFN-γ-induced increase in BAX expression (p-value = 0.002). HMOs induced distinct, developmental-stage-specific transcriptional responses. Only in pediatric IEOs, HMOs significantly upregulated 536 genes and downregulated 270 genes (adjusted p-value <0.05). Notably, lipid metabolic pathways were significantly activated (adjusted p-value <1.0x10-3). Under IFN-γ-induced inflammation, HMOs mitigated the transcriptomic changes in 83.3 % (5 out of 6) of the identified differentially expressed genes in pediatric IEOs. HMOs also attenuated the expression of key inflammation-related genes, reducing PTGES (p-value <0.05) and significantly upregulating SOCS5 (p-value <0.001).

By utilizing advanced IEOs derived from fetal and pediatric patients, we reveal that this HMO blend elicits developmental-stage-specific responses. Our study highlights the potential of HMOs to support gut health, demonstrating their ability to enhance lipid metabolism and mitigate inflammatory damage. These findings offer important insights into the role of HMOs in early-life nutrition, lending compelling evidence to support their inclusion as key components in innovative and tailored infant nutrition strategies.