Background <p>Ischemic heart disease (IHD) has a substantial burden on individuals and health system infrastructure worldwide. Meanwhile, mounting evidence has declared remarkable contrasts in gut microbiota between individuals with IHD and healthy counterparts. The Dietary Approaches to Stop Hypertension (DASH) might be one of the most reliable strategies to manage cardiometabolic risk factors. Nonetheless, no experiment has tested the impact of a DASH diet and exercise on gut microbiota composition in IHD individuals. Hence, we aim to explore the effects of a DASH diet and concurrent exercise on gut microbiota, oxidized LDL, and cardiometabolic risk factors among men.</p> Methods <p>In total, 48 men aged 40–70&#xa0;years with IHD will be recruited in this parallel randomized, controlled, 2 × 2 factorial clinical trial. These patients will be randomly assigned to the following four intervention groups: DASH diet (D), concurrent exercise (E), concurrent DASH diet and exercise (DE), and control (usual care) (C) for 8&#xa0;weeks. At baseline and the end of the study, stool samples and serum levels will be gathered to detect gut microbiota (Firmicutes, Bacteroidetes, <i>Bifidobacteria</i>, <i>clostridium</i>, <i>Faecalibacterium prausnitzi</i>, <i>Bacteroidetes</i>, and <i>Akkermansia muciniphila</i>) and cardiometabolic risk factors, as well as anthropometric measures, blood pressure, quality of life, 6-min walking test, and Beck Depression Inventory (BDI).</p> Discussion <p>Based on our information, the present study is the primary randomized controlled trial testing the impacts of short-term concurrent training and DASH diet on intestinal bacteria diversity and several cardiometabolic risk factors in men with IHD.</p> Trial registration <p>Iranian Registry of Clinical Trials (www.irct.ir, IRCT20181205041859N1). Registered on 29 September 2024.</p>