The Effect of Gender on the Intestinal Flora of Colorectal Cancer Under Different Stages

This study aims to determine whether gender is a factor in the interplay between the human intestinal flora and colorectal cancer (CRC), ultimately providing new evidence for the clinical prediction and management of CRC in different genders. In this study, we included 186 untreated CRC patients, and classified them into two groups based on pathological staging: Groups Ⅰ-Ⅱ and Groups Ⅲ-Ⅳ, with male and female groups within each group. We collected preoperative fecal samples from these patients and performed 16S rRNA gene sequencing to analyze their intestinal flora. In the CRC Stages I-II cohort, the gut microbiota of the female group exhibited greater diversity and abundance compared to the male group, with a total of 13 gut microbiota demonstrating significant disparities. Notably, s__Parabacteroides gordonii, s__Bacteroides faecis, and s__Bacteroides nordii were found to be more prevalent in the female group relative to the male group. Within the CRC Stages III-IV cohort, 51 gut microbiota exhibited significant differences between the genders. In the immunocyte composition of fecal samples from patients with CRC, a higher proportion of naive B cells is observed in the male group as compared to the female group. In female CRC patients within the CRC Stages III-IV cohort, Actinomyces exhibited a significant negative correlation with activated dendritic cells, CD4+ memory T cells, and eosinophils. In male CRC patients within the CRC Stages III-IV cohort, Actinomyces demonstrated a significant positive correlation with naive B cells and a significant positive correlation with immune activation genes TNFRSF25 and TMIGD2. In female CRC patients within the CRC Stages III-IV cohort, Actinomyces showed a significant negative correlation with activated dendritic cells, CD4+ memory T cells, and eosinophils, and a significant positive correlation with immune activation genes TNFSF13B, LTA, KLRK1, and CXCL12. In the CRC Stages I-II group, the female group's intestinal flora is more diverse and richer than the male group. In the CRC Stages III-IV group, there are a total of 51 different intestinal flora in both the male and female groups. We also found that Actinomyces affects the occurrence and development of CRC in the male and female groups through different pathways. The results show that the intestinal flora differs between male and female CRC patients and is closely associated with cancer development.