Heat map showing bidirectional causality between gut microbiota and DLBCL. (A) Causality of 131 genera on DLBCL. (B) Causality of other 4 microbiota taxonomic levels on DLBCL. (C) Causality of DLBCL on 131 genera. (D) Causality of DLBCL on other microbiota taxonomic levels. Results that reached statistical significance in the IVW analysis are marked with an asterisk (∗) and represent a P value of <.05.