Moreover, Faecalibacterium prausnitzii, the most well-known species in Faecalibacterium genus, could inhibit the secretion of interleukin-6 (IL-6) and the phosphorylation of Janus kinases 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) in breast cancer cells. Here, STAT3 is linked to breast carcinoma.