The contamination of microplastics (MPs) in food has become a global concern due to their ingestion through the food chain and associated health risks. However, the impacts of MPs on lipid digestion and absorption remain poorly understood. This study investigates the effects of MPs on soybean oil in vitro digestion and ex vivo absorption, focusing on particle size (small ~30 μm, medium ~50 μm, and large ~100 μm) and concentration (0.32, 0.64, and 1.28 mg/mL). During digestion, MPs interacted with digestive components, forming rough surface coronas and promoting aggregation, with mean size of small-sized MPs increasing by up to 57.9%. The presence of MPs inhibited soybean oil digestion and pancreatic lipase activity in a concentration- and size-dependent manner. At 1.28 mg/mL, smaller MPs (~30 μm) caused the most pronounced inhibition, reducing free fatty acid (FFA) release to 65.2%, compared to 71.1% for medium-sized MPs and 76.5% for larger MPs. Pancreatic lipase activity similarly declined to 72.0% with smaller MPs versus 83.0% with larger MPs. In the ex vivo rat small intestine model, smaller MPs significantly impaired FFA absorption, with rates dropping from 43.4% (no MPs) to 20.2% with small MPs and 31.2% with large MPs at the highest concentration. Fluorescent microscopy revealed that MPs, particularly smaller ones, adsorbed digestive enzymes and FFAs, forming physical barriers that hindered lipid migration toward intestinal villi. These findings provide mechanistic insight into how MPs disrupt lipid digestion and absorption, highlighting potential health risks of microplastic exposure.

中文翻译：

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揭示具有不同粒径和浓度的聚苯乙烯微塑料对脂质体外消化和离体吸收的影响

由于食品中的微塑料 （MP） 通过食物链摄入并存在相关的健康风险，因此其污染已成为全球关注的问题。然而，MP 对脂质消化和吸收的影响仍然知之甚少。本研究调查了 MPS 对大豆油体外消化和离体吸收的影响，重点关注粒径 （小 ~30 μm、中 ~50 μm 和大 ~100 μm） 和浓度 （0.32、0.64 和 1.28 mg/mL）。在消化过程中，MP 与消化成分相互作用，形成粗糙的表面电晕并促进聚集，小尺寸 MP 的平均大小增加高达 57.9%。MP 的存在以浓度和大小依赖性方式抑制大豆油消化和胰脂肪酶活性。在 1.28 mg/mL 时，较小的 MP （~30 μm） 引起了最明显的抑制，将游离脂肪酸 （FFA） 释放减少到 65.2%，而中型 MP 为 71.1%，较大 MP 为 76.5%。胰脂肪酶活性同样下降到较小 MP 的 72.0%，而较大的 MP 为 83.0%。在离体大鼠小肠模型中，较小的 MP 显着损害了 FFA 的吸收，在最高浓度下，小 MP 的吸收率从 43.4%（无 MP）下降到 20.2%，大 MP 的吸收率从 31.2% 下降。荧光显微镜显示，MP，尤其是较小的 MP，吸附消化酶和 FFA，形成物理屏障，阻碍脂质向肠道绒毛迁移。这些发现为 MP 如何破坏脂质消化和吸收提供了机制见解，突出了微塑料暴露的潜在健康风险。