结直肠癌（CRC）是癌症相关死亡的最主要原因之一。最近，人们发现结直肠癌的病程与肠道微生物群之间存在密切联系。维生素 K2 (VK2) 是一种细菌衍生的化合物，在人体中发挥着至关重要的作用。其显着的抗癌特性可能来自于许多化疗药物中发现的具有特定化学结构的醌环。 VK2 可以外源性地供应给我们的身体，即通过膳食补充剂或发酵食品（例如，黄奶酪、发酵大豆 - 纳豆），也可以内源性地供应给我们的身体，即通过不断在人类大肠微生物群中定殖的细菌的产生。本文重点关注由人类肠道微生物组中最活跃的成员合成的内源 K2。该分析测试了 86 种肠道来源的细菌菌株，其中选择了最大的 VK2 生产者（乳杆菌、双歧杆菌、芽孢杆菌）。此外，基于所选的 VK2-MK4 同源物，VK2 在没有脂肪、胰酶或胆盐共存的水环境中渗透到 Caco-2 细胞中的潜力已被证明。测试了三种VK2同源物：VK2-MK4、VK2-MK7和VK2-MK9对Caco-2细胞凋亡和坏死的影响，证明它们对测试细胞没有有害作用。此外，长链同源物（VK2-MK9 和 VK2-MK7）在抑制促炎细胞因子的分泌方面具有独特作用，例如 IL-8（对于 Caco-2 组织）以及 IL-6 和 TNFα（对于 RAW 264.7 ）已记录。© 2023。作者。

Colorectal cancer (CRC) is one of the foremost causes of cancer-related deaths. Lately, a close connection between the course of CRC and the intestinal microbiota has been revealed. Vitamin K2 (VK2) is a bacterially derived compound that plays a crucial role in the human body. Its significant anti-cancer properties may result, inter alia, from a quinone ring possessing a specific chemical structure found in many chemotherapeutics. VK2 can be supplied to our body exogenously, i.e., through dietary supplements or fermented food (e.g., yellow cheese, fermented soybeans -Natto), and endogenously, i.e., through the production of bacteria that constantly colonize the human microbiome of the large intestine.This paper focuses on endogenous K2 synthesized by the most active members of the human gut microbiome. This analysis tested 86 intestinally derived bacterial strains, among which the largest VK2 producers (Lactobacillus, Bifidobacterium, Bacillus) were selected. Moreover, based on the chosen VK2-MK4 homolog, the potential of VK2 penetration into Caco-2 cells in an aqueous environment without the coexistence of fats, pancreatic enzymes, or bile salts has been displayed. The influence of three VK2 homologs: VK2-MK4, VK2-MK7 and VK2-MK9 on apoptosis and necrosis of Caco-2 cells was tested proving the lack of their harmful effects on the tested cells. Moreover, the unique role of long-chain homologs (VK2-MK9 and VK2-MK7) in inhibiting the secretion of pro-inflammatory cytokines such as IL-8 (for Caco-2 tissue) and IL-6 and TNFα (for RAW 264.7) has been documented.© 2023. The Author(s).