Summary of ongoing clinical trials and observational studies in breast cancer treatment in relation to gut microbiota

Study Aims Study type Sample size
“Engineering gut microbiome to target breast cancer” [42] To determine whether probiotics will help the body’s immune system react to breast cancer Clinical trial 7
“Gut microbiome and GI toxicities as determinants of response to neoadjuvant chemo for advanced breast cancer” [41] To determine whether gut microbial composition can influence immune response to the tumour, resulting in inter-individual differences in the response to anti-cancer therapies Clinical trial 40
“Intestinal microbiota of breast cancer patients undergoing chemotherapy” [43] To study specific types (or groups) of bacteria that promote the occurrence, development, and mechanism of breast cancer Observational 80
“Breast cancer and its relationship with the microbiota” [44] To examine associated between composition and functionality of the mammary/gut microbiota with breast cancer risk, and to determine if exposure to environmental contaminants [endocrine disruptors, endocrine disrupting chemicals (EDCs)] can alter the microbiota? Observational 200
“Determinants of acquired endocrine resistance in metastaticbreast cancer: a pilot study” [45] To identify markers of endocrine resistance in ctDNA and the gut microbiome in patients with estrogen (Oestrogen) receptor positive (ER+) HER2 metastatic breast cancer Observational 20
“Study to investigate efficacy of a novel probiotic on the bacteriome and mycobiome of breast cancer” [46] To examine the effect of probiotics on the breast tumour microbiome and gut microbiome in breast cancer Clinical trial 100
“Effects of chemotherapy on intestinal bacteria in patients with newly diagnosed breast cancer” [47] To study effects of chemotherapy on intestinal bacteria/organisms in patients newly diagnosed with breast cancer Observational 36
“ARGONAUT: stool and blood sample bank for cancer patients” [40] To determine whether the microbiota composition can predict progression-free survival.
Whole genome sequencing and metabolomics will be used to characterize the patient’s microbiome, and whether there is any correlation with response to treatment
Observational 4,000
“Gut and intratumoural microbiome effect on the neoadjuvant chemotherapy-induced immunosurveillance in triple negative breast cancer” [48] To determine if the probability of pathologic complete response in triple negative breast cancer patients treated with standard of care neoadjuvant chemotherapy is correlated with variability in the composition of intestinal and intra-tumoral microbiota and subsequent short-term alterations in composition Observational 49
“The clinical study of modern therapies on flora in body fluids and blood of malignant tumour patients” [49] To study what modern therapies lead to the influence of microecological environment including diversity and abundance of bacteria in patients who received malignant tumours Observational 500