Laboratory for Conservation Biology, Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland.
University Center of Legal Medicine Lausanne and Geneva, Lausanne University Hospital (CHUV) and University of Lausanne, Ch. de la Vulliette 4, 1000, Lausanne 25, Switzerland.
Sci Rep. 2021 Apr 23;11(1):8876. doi: 10.1038/s41598-021-88418-x.
Stomach content analyses are a valuable tool in human forensic science to interpret perimortem events. While the identification of food components of plant and animal origin has traditionally been conducted by macro- and microscopical approaches in case of incomplete digestion, molecular methods provide the potential to increase sensitivity and taxonomic resolution. In particular, DNA metabarcoding (PCR-amplification and next generation sequencing of complex DNA mixtures) has seen a rapid growth in the field of wildlife ecology to assess species' diets from faecal and gastric samples. Despite clear advantages, molecular approaches have not yet been established in routine human forensics to investigate the last meal components of deceased persons. In this pilot study we applied for the first time a DNA metabarcoding approach to assess both plant and vertebrate components of 48 human stomach content samples taken during medicolegal autopsies. We obtained a final dataset with 34 vertebrate and 124 vegetal unique sequences, that were clustered to 9 and 33 operational taxonomic units (OTUs), respectively. Our results suggest that this approach can provide crucial information about circumstances preceding death, and open promising perspectives for biomedical dietary surveys based on digested food items found in the gastrointestinal tract.
胃内容物分析是法医学中一种有价值的工具，可用于推断死后发生的事件。虽然传统上对于未完全消化的检材，通过宏观和微观方法来鉴定植物和动物源性食物成分，但分子方法具有提高灵敏度和分类分辨率的潜力。特别是 DNA 代谢组学（对复杂 DNA 混合物进行 PCR 扩增和下一代测序）在野生动物生态学领域得到了快速发展，可用于从粪便和胃样本中评估物种的饮食。尽管分子方法具有明显的优势，但尚未在常规法医中建立起来，以研究死者的最后一餐成分。在这项初步研究中，我们首次应用 DNA 代谢组学方法来评估 48 个人体胃内容物样本中的植物和脊椎动物成分，这些样本是在法医学尸检期间采集的。我们获得了一个最终数据集，其中包含 34 个脊椎动物和 124 个植物的独特序列，分别聚类为 9 和 33 个操作分类单元（OTUs）。我们的研究结果表明，这种方法可以提供关于死亡前情况的关键信息，并为基于胃肠道中发现的消化食物项目的生物医学饮食调查开辟了有希望的前景。
