Vinegar intake in patients undergoing responders to immune checkpoint inhibitor therapy: food frequency questionnaire study

Hirotsugu Ariizumi^1*Miyuki Shimazui²Chisato Ogawa²Mika Kaneki²Nanaho Saito²Emiko Mura¹Risako Suzuki¹Toshiaki Tsurui¹Nana Iriguchi¹Tomoyuki Ishiguro¹Yuya Hirasawa¹Masahiro Shimokawa¹Ryotaro Ohkuma¹Yutaro Kubota¹ATSUSHI HORIIKE¹Satoshi Wada¹KIYOSHI YOSHIMURA¹Kouzou Murakami¹Takuya Tsunoda¹

• ¹Showa University, Shinagawa, Japan
• ²Showa Daigaku Byoin, Shinagawa, Japan

Introduction: The gut microbiome is increasingly recognized as a key modulator of immune checkpoint inhibitor (ICI) efficacy. Dietary factors, particularly fibers, may influence the microbiome and thus affect the ICI response. Although Western studies have suggested a link between high fiber intake and better outcomes, this relationship remains unclear in Japanese populations with different dietary habits. This study investigated dietary components associated with ICI response in Japanese patients with cancer. Methods: In total, 32 patients with carcinomas treated with ICIs were enrolled. Nutritional customs before ICI infusion were analyzed using a food frequency questionnaire. Results: Among the 331 dietary items, only vinegar (acetic acid) intake showed an independent association with the treatment response. Higher vinegar consumption correlated with significantly lower odds of nonresponse (P = 0.017). In contrast, total and fermentable dietary fiber intake showed no significant association with ICI efficacy or survival outcomes. This is a provisional file, not the final typeset article Conclusions: Higher vinegar intake is associated with better may enhance the ICI response in Japanese patients, whereas fiber has a limited effect. Thus, tailored Tailored dietary strategies are needed for optimal outcomes.