Table 1.

The ecological and network differences of microgenderome and their implications

Ecological and/or network properties	General assessment on the sex difference	Implications
Species diversity	(i) 7 out of 15 sites exhibited significant sex differences (M > F in five sites, and F > M in two sites), but some differences may only be detected at phylum or core/periphery level. (ii) At the whole community level, skin microbiome exhibited the most prevalent sex differences (M > F), but gut did not surprisingly.	Sex factor should not be ignored in diversity analysis, particular for key phyla such as: Actinobacteria, Bacteroidetes, and Firmicutes.
Shared species	(i) Except for the oral, there are sex‐specific species in the airway, gut, and skin microbiomes. (ii) With phyla Bacteroidetes and Firmicutes, gut microbiome is the only site with significant difference in shared species.	Species composition is highly sex‐specific, and there are sex‐specific species for each sex. Our study presented the list of sex‐specific species.
Heterogeneity scaling	Intersubject community heterogeneity scaling (change) is not sex‐specific.	This means sex makes no differences in intersubject community heterogeneity, and diversity changes across cohorts or populations.
Diversity scaling	Diversity scaling and potential diversity are not sex‐specific.
Basic species co‐occurrence networks (SCN)	(i) “Yin and Yang” are balanced, given that the P/N ratio is not sex‐specific; (ii) There are sex‐specific trio motifs; (iii) Most other basic network properties exhibited mixed results.	The functionalities of those sex‐specific special trios motifs are worthy of further investigations.
Core/periphery network (CPN)	(i) Both observed‐network and permutated network test strategies cross‐verified that core/periphery structures are sex‐specific at all sites. (ii) In 40–70% sites, the CPN properties are influenced significantly by sex, depending on specific site and/or specific CPN property.	CPN and HSN analyses reveal sex‐specific, differential effects among microbial species, which are the selection effects according to Vellend–Hanson synthesis. This is because selection is about the inequality (asymmetry), and CPN/HSN can effectively detect the inequalities from either node or link perspective. Hence, the microgenderome is primarily due to sex‐specific selection effects between man and woman.
High‐salience skeleton network (HSN)	(i) The shared high‐salience skeletons (backbone or critical paths in species interactions) are sex‐specific in all but two oral sites. But more frequently used backbones are less sex‐specific and show much sexual congruity. (ii) Virtually all HSN properties were sex‐specific, exhibited the prevalent sex differences in species interactions.