Ultra-processed foods (UPFs) and food additives have become ubiquitous components of the modern human diet. There is increasing evidence of an association between diets rich in UPFs and gut disease, including inflammatory bowel disease, colorectal cancer and irritable bowel syndrome. Food additives are added to many UPFs and have themselves been shown to affect gut health. For example, evidence shows that some emulsifiers, sweeteners, colours, and microparticles and nanoparticles have effects on a range of outcomes, including the gut microbiome, intestinal permeability and intestinal inflammation. Broadly speaking, evidence for the effect of UPFs on gut disease comes from observational epidemiological studies, whereas, by contrast, evidence for the effect of food additives comes largely from preclinical studies conducted in vitro or in animal models. Fewer studies have investigated the effect of UPFs or food additives on gut health and disease in human intervention studies. Hence, the aim of this article is to critically review the evidence for the effects of UPF and food additives on gut health and disease and to discuss the clinical application of these findings.

超加工食品（UPF）和食品添加剂已成为现代人类饮食中无处不在的组成部分。越来越多的证据表明，富含 UPF 的饮食与肠道疾病（包括炎症性肠病、结直肠癌和肠易激综合征）之间存在关联。许多 UPF 中都添加了食品添加剂，其本身已被证明会影响肠道健康。例如，有证据表明，一些乳化剂、甜味剂、色素以及微粒和纳米颗粒对一系列结果有影响，包括肠道微生物组、肠道通透性和肠道炎症。一般来说，UPF对肠道疾病影响的证据来自观察性流行病学研究，而相比之下，食品添加剂影响的证据主要来自体外或动物模型中进行的临床前研究。在人类干预研究中，很少有研究探讨 UPF 或食品添加剂对肠道健康和疾病的影响。因此，本文的目的是批判性地审查 UPF 和食品添加剂对肠道健康和疾病影响的证据，并讨论这些发现的临床应用。