In the quest to better understand the complexities of human lactation, a team of researchers at the University of Twente in the Netherlands has pioneered a novel approach by investigating the optical properties of human milk through light scattering techniques. This research not only provides critical insights into the biochemical composition of breast milk but also opens new pathways for noninvasive, real-time monitoring of milk quality and sufficiency, a breakthrough that could have profound implications for infant nutrition and maternal health worldwide.
Breastfeeding is universally heralded for its critical role in infant health and development, a fact underscored by the World Health Organization’s recommendation of exclusive breastfeeding for the first six months of life. Despite these guidelines, a significant percentage of mothers—ranging from 40 to 60 percent—cease breastfeeding prematurely, a cessation often rooted in fears of inadequate milk supply. Recent studies, however, suggest that these fears may often be grounded in reality, with lactation insufficiency affecting approximately 10 to 15 percent of breastfeeding women, though the physiological factors driving this condition remain largely elusive.
Traditionally, measuring milk intake and composition has posed technical challenges due to the invasive nature of sampling and the complexity of milk’s biochemical matrix. Recognizing this gap, scientists have turned to photonics and biophotonics—fields that exploit light interactions with biological matter—to develop innovative, noninvasive analytical methods. Light scattering, a phenomenon whereby particles in a medium redirect incident light in various directions, serves as a rich source of information about particle size, distribution, and composition within the milk.
The research group at the University of Twente has focused particularly on the role of milk fat globules (MFGs) and extracellular vesicles (EVs), which are microscopic components essential for delivering energy and bioactive molecules to the infant. By quantifying the refractive index—a measure of how light bends as it passes through these particles—and analyzing their size and concentration, the researchers have mapped out the biological variability inherent in human milk across individuals and time.
In the first of two pivotal studies published in the journal Biophotonics Discovery, the team collaborated with the University of Amsterdam to determine the precise refractive indices of MFGs and EVs. Their findings revealed significant differences between the optical properties of human milk fats compared to those found in cow’s milk, commonly used as a reference in milk research. This disparity emphasizes the importance of using human-specific parameters to improve the accuracy and reliability of milk analysis methodologies.
Building on this foundational work, the second study delved into how these measured refractive indices, along with other specific milk properties such as fat concentration and particle size distribution, influence light scattering behavior. By incorporating these variables into predictive models, the researchers demonstrated that not only does the fat concentration markedly affect light scattering, but the size distribution of milk fat particles also plays a crucial role. Importantly, variations in refractive indices between different human milk samples had a minimal impact on scattering differences, underscoring the dominant influence of particle size and concentration.
This nuanced understanding of the optical dynamics in human milk holds significant promise for developing compact, rapid light scattering devices capable of analyzing milk composition on the fly. Unlike traditional biochemical assays that require sample destruction or complex preparation, light scattering enables nondestructive analysis, preserving the milk for infant consumption after testing. Such technology could revolutionize the monitoring of milk quality throughout a single breastfeeding session, providing real-time feedback to mothers and healthcare providers.
The potential applications extend beyond individual lactation monitoring; this technology could facilitate large-scale studies into lactation insufficiency’s underlying causes, enabling personalized interventions that address the physiological hurdles mothers face. By bridging the gap between biophotonics research and clinical practice, this work underscores a vital interdisciplinary advance in maternal and neonatal health.
Furthermore, the researchers’ methodological innovation demonstrates the broader applicability of photonics for studying complex biological fluids. The detailed characterization of milk’s light scattering behavior paves the way for similar optical investigations into other bodily fluids and tissues, potentially enhancing diagnostics and therapeutics across medicine.
Notably, the collaborative nature of this research—melding expertise from photonics, biology, and lactation science—exemplifies the importance of cross-disciplinary approaches to solving intricate health problems. This synergy is vital for transforming basic scientific insights into tools that tangibly improve health outcomes.
While the promise of light scattering-based human milk analysis is compelling, continued research and technological refinement remain essential. Future studies will likely explore the integration of these optical methods into portable devices and assess their efficacy in diverse populations and clinical settings. This will ensure that the benefits of this technology are accessible to mothers globally, addressing disparities in breastfeeding support.
In summary, the University of Twente team’s research marks a significant milestone in lactation science by elucidating how intrinsic physical properties of human milk govern its optical signatures. Their findings lay a strong foundation for innovative, noninvasive diagnostic tools that could transform the landscape of breastfeeding support and neonatal nutrition, ultimately enhancing the health trajectories of countless infants and families worldwide.
Subject of Research: Not applicable
Article Title: Influence of sample-specific properties on light scattering by human milk
News Publication Date: 9-Mar-2026
Web References:
https://www.spiedigitallibrary.org/journals/biophotonics-discovery/volume-3/issue-01/012104/Refractive-index-of-milk-fat-globules-and-extracellular-vesicles-in/10.1117/1.BIOS.3.1.012104.full
https://www.spiedigitallibrary.org/journals/biophotonics-discovery/volume-3/issue-01/012105/Influence-of-sample-specific-properties-on-light-scattering-by-human/10.1117/1.BIOS.3.1.012105.full
References:
“Refractive index of milk fat globules and extracellular vesicles in human milk,” J. R. de Wolf et al., Biophoton. Discovery 3(1), 012104 (2026), doi: 10.1117/1.BIOS.3.1.012104
“Influence of sample-specific properties on light scattering by human milk,” W. Verveld et al., Biophoton. Discovery 3(1), 012105 (2026), doi: 10.1117/1.BIOS.3.1.012105
Image Credits: W. Verveld, J.R. de Wolf, and N. Bosschaart (University of Twente)
Keywords
Physics, Electromagnetic radiation, Light
