Association of food insecurity on gut microbiome and metabolome profiles in a diverse college-based sample

Voluntary caloric restriction (e.g., eating disorders) often results in alterations in the gut microbiota composition and function. However, these findings may not translate to food insecurity, where an individual experiences inconsistent access to healthy food options. In this study we compared the fecal microbiome and metabolome of racially and ethnically diverse first year college students (n=60) experiencing different levels of food access. Students were dichotomized into food secure (FS) and food insecure (FI) groups using a validated, 2-question screener assessing food security status over the previous 30 days. Fecal samples were collected up to 5 days post survey-completion. Gut microbiome and metabolome were established using 16S rRNA amplicon sequencing, targeted liquid chromatography-tandem mass spectrometry, and gas chromatography-mass spectrometry. FI students experienced significantly greater microbial diversity with increased abundance of Enterobacteriaceae and Eisenbergiella, while FS students had greater abundance of Megasphaera and Holdemanella. Metabolites related to energy transfer and gut-brain-axis communication (picolinic acid, phosphocreatine, 2-pyrrolidinone) were elevated in FI students (q < 0.05). These findings suggest that food insecurity is associated with differential gut microbial and metabolite composition for which the future implications are unknown. Further work is needed to elucidate the longitudinal metabolic effects of food insecurity and how gut microbes influence metabolic outcomes.

自愿性热量限制（如进食障碍）通常会导致肠道菌群（gut microbiota）的组成与功能发生改变。然而，上述研究结论或许并不适用于食物不安全（food insecurity）人群——这类个体无法持续获取健康食物。本研究纳入60名种族与族裔多元化的大学一年级学生，根据其食物获取状况的差异，对比分析了粪便微生物组（fecal microbiome）与代谢组（metabolome）。研究人员采用经过验证的2项问题筛查量表，基于受试者过去30天内的食物安全状况，将其分为食物安全（FS）组与食物不安全（FI）组。粪便样本于问卷完成后5天内采集。通过16S rRNA扩增子测序（16S rRNA amplicon sequencing）、靶向液相色谱-串联质谱（targeted liquid chromatography-tandem mass spectrometry）及气相色谱-质谱联用（gas chromatography-mass spectrometry）技术，对肠道微生物组与代谢组进行测定。结果显示，食物不安全组学生的微生物多样性显著更高，肠杆菌科（Enterobacteriaceae）与艾森伯格菌属（Eisenbergiella）的丰度显著升高；而食物安全组学生的巨球形菌属（Megasphaera）与霍尔德曼菌属（Holdemanella）丰度更高。与能量转运及肠-脑轴（gut-brain-axis）信号传导相关的代谢物（吡啶甲酸、磷酸肌酸、2-吡咯烷酮）在食物不安全组学生中显著上调（q<0.05）。本研究结果表明，食物不安全与肠道微生物及代谢物组成的差异存在关联，但其后续的潜在影响尚不明确。未来仍需开展更多研究，以阐明食物不安全对代谢的长期效应，以及肠道微生物如何调控代谢结局。