Utilizing Magnetic Resonance Imaging to Investigate Milk Digestion Dynamics and Nutrient Bioavailability in Humans

Abstract

Abstract : In this study, we use a special type of MRI called Magnetization Transfer MRI to watch — in real time and without any invasive procedures — how milk proteins clump together and leave the stomach. We then look at how different levels of protein unfolding (caused by heating) affect how these proteins are digested in people. Methods: Twelve healthy adults drank 300 g of skimmed milk that had been pasteurized either at a low temperature (LPSM) or a high one (HPSM), to give different levels of protein denaturation. We then took a series of MRI scans using a 3T clinical machine over 95 minutes after they had eaten. From these scans, we measured things like the magnetization transfer ratio (MTR), which we used to estimate how much the proteins had coagulated, the volume of food in the stomach, and how much of it was liquid versus semisolid. We also asked the participants how hungry they felt and whether they experienced any gastrointestinal discomfort Results: After drinking both LPSM and HPSM, the MTR steadily went up, showing that proteins were coagulating. There wasn’t a statistically significant difference in how MTR changed between the two milk types (p ≈ 0.15), which suggests that pasteurization temperature didn’t strongly affect coagulation itself. But the HPSM group’s stomach emptied more slowly — they had about 40 mL more left in their stomach at similar times (p = 0.044). There was a tendency for HPSM to form more semi-solid matter and less liquid, although these trends weren’t quite statistically significant (semi-solid: p ≈ 0.056; liquid: p ≈ 0.065). Finally, people’s feelings of hunger, fullness, bloating, and nausea didn’t differ noticeably between the two milk conditions. Conclusion: MT MRI gives us a powerful, non-invasive way to look at how food behaves in the stomach — both how proteins gel together and how the stomach empties — with very high sensitivity. In our study, even though both milk types coagulated in a similar way, the high-heat milk emptied more slowly from the stomach. That slower digestion could delay when nutrients reach your body. Importantly, this shows how the physical structure of food — altered by processing — can change how our gut handles it. These insights could help us design better functional foods.