Physical activity undertaken by different groups of individuals results in the rearrangement of microbiota composition towards a symbiotic microbiota profile. This applies to both healthy and diseased individuals. Multiple myeloma (MM), one of the more common hematological malig-nancies, predominantly affects older adults. Identifying an appropriate form of physical activity for this patient group remains a challenge. The aim of the study was to investigate the impact of a 6-week Nordic Walking (NW) training program combined with a 10/14 time restricted eating regimen on the gut microbiota composition of multiple myeloma patients. The study included healthy individuals as the control group (n=16; mean age 62.19 ± 5.4) and patients with multiple myeloma in remission (MM group; n=16; mean age 65.00 ± 5.13, mean disease duration 57 months). The training intervention was applied to the patient group and consisted of three moderate-intensity sessions per week, individually tailored to the estimated physical capacity of each participant. Taxonomic composition was determined using 16S rRNA sequencing (V3-V9 regions). The microbiota composition was compared between the patient group and the control group. The gut microbiota of the patients was predominantly represented by the phyla Firmicutes, Actinobacteria, Verrucomicrobia, Proteobacteria, and Bacteroidetes. The training, combined with intermittent fasting, stimulated an increase in biodiversity and taxonomic rearrangement of gut microbiota species. The observed changes confirm the safety and beneficial effects of the proposed intervention in the patient group during the plateau phase of multiple myeloma.