The gut microbiome is more stable in males than in females during the development of colorectal cancer

Abstract Background Gut microbial shifts have great potential to predict the risk of colorectal cancer, but how gut microbes respond to the development of colorectal cancer in males and females at the community scale is unknown. To address this question, we reanalyzed the dataset from a published project and grouped these data depending on sex into three groups, healthy, colorectal adenoma and carcinoma individuals, and community assembly and network patterns of gut microbes were evaluated by null model and co-occurrence network-based methods. Results The study showed that distinct changes in microbial α -diversities and community composition were observed between the male and female gut. Specifically, the microbial α -diversities did not significantly change in the male gut ( P > 0.05) but were lowered in the female gut ( P < 0.05), suggesting that permanent species loss might occur in the female gut during the development of colorectal cancer. These distinct changes in microbial α -diversities and community composition between the male and female gut might result from host immunity mechanisms and different microbial community assemblies in males and females. Indeed, we found that the microbial community tended to be primarily stochastic in males, whereas it became increasingly deterministic in females with the development of colorectal cancer. Moreover, microbial co-occurrence associations tended to be more complicated when communities were primarily driven by stochastic processes in males; rare species were enriched in the co-occurrence network of the male gut, whereas key species loss was observed in the co-occurrence network of the female gut. Conclusions Our findings indicate that microbial communities in the male gut are more stable than those in the female gut and that microbial community assembly in the gut is sex-dependent with the development of colorectal cancer. Our study suggests that sexual dimorphism needs to be taken into account to better predict the risk of colorectal cancer based on microbial shifts.