In a paper published very recently in Advanced Science, Prof. Sam MA (a member of CCEAEG) and Ms. Wendy LI from Kunming Institute of Zoology, Chinese Academy of Sciences present seven aspects of the sex differences in the human microbiomes at 15 body sites, including oral, gut, skin and airway.
Formally, the sex differences or sexual dimorphism in the human microbiomes are referred to as microgenderome, a term coined by M. B. Flak (Science 2013) in commenting a study by JG Markle et al (Science 2013) on the relationship between susceptibility to diabetes and gut microbiome with the mouse model. MA and LI’s study provides references or baselines for further investigating the relationships between human microbiomes and disease susceptibilities , particularly autoimmune diseases, such as type-I diabetes. For example, type-I diabetes is about twice as common in women as it is in men, but gout is significantly more common in men than in women. Researchers have discovered numerous similar cases in other diseases including neurodegenerative diseases and certain cancers. It is now widely believed that human microbiomes may play a critical role for the disease-susceptibility differences through their interactions with hormones and immune systems, or the gut-microbiome-brain communications.
Microgenderome or sexual dimorphism in the human microbiome refers to the bidirectional interactions between microbiotas, sex hormones and immune systems, and it is highly relevant to disease susceptibility. A critical step in exploring microgenderome is to dissect the sex differences in key community ecology properties, which has not been systematically analyzed before MA and LI’s study. Their study filled the gap by reanalyzing the HMP (human microbiome project) datasets with two objectives. Firstly, the research dissected the sex differences in community diversity and their inter-subject scaling, species composition, core/periphery species and high-salience skeletons (species interactions) in the microbiome networks. Secondly, the study offered mechanistic interpretations for the sexual dimorphism or microgenderome. Methodologically, seven approaches reflecting the state-of-the-art research in medical ecology of human microbiomes are harnessed to achieve their objectives. Actually, most analytic approaches used in the study have been developed by Prof. MA’s lab (Computational Biology and Medical Ecology Lab of Kunming Institute of Zoology, Chinese Academy of Sciences) during the last few years.
MA & LI postulated that the discovered microgenderome characteristics, categorized as seven aspects of differences/similarities, exert far reaching influences on disease susceptibility, and are primarily due to the sex difference in evolutionary selection effects (deterministic fitness differences in microbial species and/or species interactions with each other or with their hosts), which are, in turn, shaped/modulated by host physiology (immunity, hormones, gut-brain communications, etc).
The research was published in Advanced Science. Link to the paper: https://doi.org/10.1002/advs.201902054