Most cancer patients receiving chemotherapy are accompanied by gut dysbiosis and intestinal mucosal barrier dysfunction to a greater or lesser degree. These disorders of the gut can easily cause bacterial translocation, resulting in the formation of immunothrombosis composed mainly of neutrophil extracellular traps and activated platelets in hepatic sinusoid in order to trap bacteria. At the same time, however, a lot of alarmin such as HMGB1, S100A8/S100A9 and VEGF‒A which are released from immunothrombosis, promote to recruit many myeloid‒derived suppressor cells(MDSCs)from bone marrow, leading to the strong immunosuppressive milieu in both liver and cancerous lesions. Therefore, intestinal care must be necessary for protection of intestinal barrier integrity during chemotherapy. Recently, we found that intestinal care using oral L‒glutamine‒ enriched supplement and probiotics including Lactobacillus casei Shirota supplement(Yakult®)and Clostridium butyricum MIYAIRI 588 strain(Miya‒BM®)could induce a strong anti‒tumor immune response through the induction of fully mature tertiary lymphoid structures in some pancreatic cancer patients who received 3 cycles of preoperative chemotherapy(gemcitabine 1,000 mg/m2 plus nab‒paclitaxel 125 mg/m2 on days 1, 8, and 15 of 28‒day cycle). In this review article, we discussed the role of intestinal care in the induction of fully mature tertiary lymphoid structures in cancer patients receiving chemotherapy.