IGF1 and prostate cancer: Oral administration of an antibiotic mixture along with a high-fat diet that included a substantial amount of lard in a mouse model for prostate cancer resulted in an increase in Rikenellaceae and Clostridiales, inhibited prostate cancer cell proliferation, and reduced prostate Igf1 expression as well as circulating insulin-like growth factor-1 (IGF1) levels, which are known to directly promote the proliferation of prostate cancer cell lines [150].