Two Walnut Halves (IMAGE) University of Connecticut Caption Walnuts may alter the gut microbiome so as to discourage development of cancerous tumors, according to UConn Health research soon to be published in Cancer Prevention Research. Credit California Walnut Commission Usage Restrictions Please use only with designated credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.