Precise nutritional diagnosis in digestive system malignancies based on blood nutrients, inflammatory makers,...

Malnutrition is one of the major factors leading to adverse clinical outcomes in cancer. The persistence of malnutrition, inflammatory responses, and intestinal dysfunction form a vicious cycle throughout the disease course in cancer patients. Consequently, simple nutritional therapy alone often has limited clinical efficacy. This study aims to explore precision nutrition diagnosis in patients by examining plasma nutrients, inflammatory markers and intestinal function indicators combined with body composition.

Peripheral blood samples were collected from 140 patients with digestive system malignancies, including 87 patients with severe malnutrition (study group: patient-generated subjective global assessment (PG-SGA) ≥ 9) and 53 patients with good nutritional status (control group: PG-SGA ≤3). Plasma untargeted metabolomics were analyzed using Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry. Simultaneously, inflammatory markers and intestinal mucosal barrier function markers were detected. Whole genome sequencing was utilized to examine gut microbiota in fecal samples.

A total of 129 differential plasma nutrients were discerned. Clinically concerned metabolites included essential amino acids, essential fatty acids, ketone bodies, nucleotides, vitamins and their metabolites, as well as microbiota metabolites were further analyzed. Among them, severely malnourished patients exhibited significant reductions in l-tryptophan, uridine, vitamin A, and pyrocatechol sulfate compared to the control group. Conversely, levels of lysine, l-phenylalanine, N-lactoyl methionine, arachidonic acid, docosapentaenoic acid, 3-hydroxybutyric acid, and 4-pyridoxic acid were elevated. Compared to the control group, the study group showed significantly higher levels of all inflammatory markers (p < 0.01). Additionally, d-lactate levels were notably increased in the study group (p < 0.001). Microbiota analysis demonstrated significant abnormalities in the gut microbiota at both the phylum and genus levels (LAD>2.5) between the two groups. Furthermore, body mass index (BMI) was remarkable lower in severely malnourished patient (p < 0.05). Based on these differential indicators, six key markers (l-tryptophan, uridine, vitamin A, catechol sulfate, interleukin-6 (IL-6), and BMI) were ultimately selected to establish a precision nutrition diagnostic model, achieving an AUC value of 0.979 (95 % CI: 0.961-0.998) with a Youden index of 0.866, indicating high diagnostic accuracy.

The study demonstrate significant abnormalities in blood nutrient levels, inflammatory factor, and intestinal function indicator among patients with severe malnutrition. Integrating these findings will facilitate precise nutritional diagnosis and guide precision nutritional interventions to optimize clinical outcomes.