Table 1. Studies on sex-dimorphism in the gut microbiome, nutrition and metabolic diseases.

Summary of gut microbiome-relevant sex-dimorphic host response to diet and metabolism in human and model organism studies

Condition	Organism	Sex-dimorphic effect	Reference
Diet – CR	Mouse	- CR altered age-related microbiome composition only in female mice	(30)
Diet – HFD	Mouse	- Male vs. female mice gained more weight on the same diet - Gut microbiota of females had higher abundance in Parabacteroides, Lactobacillus, Bacteroides and Bifidobacterium vs. males on the same diet	(87)
Diet – high fat overfed	Zebrafish	- HFD regime significantly affected only males - Males overfed with HFD presented with higher abundances of Proteobacteria and Gammaproteobacteria vs. females on the same diet	(82)
Diet – high fat, high sugar vs. low fat, low sugar	Mouse	- Male mice fed with high fat, high sugar diet gained more weight vs. females on the same diet - Male mice fed with high fat, high sugar diet had increased abundances of Allobaculum, whereas female fed had reduced levels of Allobaculum	(33)
Diet – Methionine restriction	Mouse	- Methionine-restricted diet increased Bacteroidaceae and Verrucoccaceae, and decreased Rumminococcaceae in males, whereas it decreased Bacteroidaceae, Verrucoccaceae and Rumminococcaceae in females	(115)
Diet – vegetarian and inulin-supplemented	Mouse (Fecal microbiota transfer)	- Microbiota recipient male and female mice showed different microbial profiles after grafting - Parabacteroides distasonis and Blautia faecis overrepresented in male recipients; Clostridium and Escherichia fergusonii/Shigella sonnei overrepresented in female recipients	(117)
Obesity - HFD	Mouse	- HFD decreased abundance of Bacteroidetes and increased levels of Firmicutes and Actinobacteria in ovariectomized female mice - Treatment with E2 slowed down the changes in the gut microbial profiles induced by HFD	(1)
Obesity/fat distribution	Human	- Distinct microbial species between males and females contribute to sex-dimorphic fat distribution patterns	(76)
Obesity/Body mass index	Human	- Fusobacterium is enriched in obese males, whereas Bifidobacterium, Coprococcus and Dialister genera are enriched in obese females	(40)
Type 1 diabetes	Mouse	- Female nonobese diabetic mouse model of type 1 diabetes [T1D] are more prone to develop T1D - Female mice grafted with male fecal microbiota were less likely to develop T1D	(67)
Metabolic syndrome predisposition	Human	- Females with metabolic syndrome shows high levels of Collinsella, Alistipes, Anaerotruncus and Phascolarctobacterium - Males with metabolic syndrome shows high levels of Faecalibacterium and Prevotella	(95)