High fecal Fn abundance compared to negative fecal Fn abundance was associated with a suggestive 3‐fold increased risk of cachexia onset at 6 months post‐surgery (OR = 3.62, 95% CI = 0.82, 15.95, p = 0.09), whereas low fecal Fn abundance compared to negative fecal Fn abundance was associated with a suggestive 71% decreased risk of cachexia onset at 6 months post‐surgery (OR = 0.29, 95% CI = 0.07, 1.10, p = 0.07) (Table S5). Here, FN1 is linked to Cachexia.