Table 1.
Summary of human and mouse studies investigating the sexual dimorphisms of intestinal microbiota in obesity.
| Model | Age | Physiological effects | Main findings | Ref |
|---|---|---|---|---|
| 4-months of either moderately high-protein or LFD in patients with BMI > 25kg/m2 | N/A | Weight loss: ↓ BMI, total & visceral fat, BP, total glucose, LDL cholesterol, leptin, and insulin regardless of diet or sex. | Weight loss-related changes to the intestinal microbiota occurred in a sex- and diet-specific manner. | (125) |
| Men & post-menopausal women, split based on BMI, following either a Mediterranean or low-fat diet. | ♂: 61.2±1.3y ♀: 60.3±1.4y |
N/A: study did not compare physiological parameters between sexes or groups. | Obesity influenced sex differences in gut microbiota. ♂: ↓ Bacteroides abundance with ↑ BMI; ↑ Methanobrevibacter abundance (vs. ♀) regardless of BMI. ♀: ↔ Bacteroides abundance with ↑ BMI; ↑ Bilophila abundance (vs. ♂) regardless of BMI. |
(82) |
| C57BL/6 mice fed either a NCD or HFD (60% fat) for 20 weeks. | 8 weeks old | ♂: ↑ weight gain for the first 7 weeks on HFD vs. ♀. No sex differences following this timepoint. |
Sex differences existed in diversity and structure of the gut microbiota at baseline. Gender-specific changes to gut microbiota occurred following HFD. |
(113) |
| C57BL/6 mice fed either a LFLS (10% total fat) or HFHS (45% total fat) for 14 weeks. | 8 weeks old | ♂: HFHS ↑ weight gain and plasma leptin vs. ♀ HFHS mice. | Significant differences in gut microbiota between males and females in both LFLS and HFHS groups. Diet-induced changes to Firmicutes differed between males and females for certain genera. |
(126) |
| C57BL/6 mice fed either a LFD (10% total fat) or HFD (60% total fat) for 20 weeks. | 6 weeks old | HFD increased body weight in males and females however, males developed obesity much earlier than female mice. | ♂: HFD ↓ Bacteroidetes, Proteobacteria & Tenericutes; ↑ Firmicutes. LFD ↓ Proteobacteria & Tenericutes; ↑ Bacteroidetes; ↔ Firmicutes. ♀: HFD ↓ Firmicutes & Tenericutes; ↑ “others”; ↔ Bacteroidetes. LFD ↓ Firmicutes & Tenericutes; ↑ Bacteroidetes & “others”. |
(127) |
BMI, body mass index; BP, blood pressure; HFD, high fat diet; HFHS, high fat, high sugar diet; LDL, low-density lipoprotein; LFD, low fat diet; LFLS, low fat, low sugar diet; N/A, not applicable; NCD, normal control diet; ref, reference.♂, male; ♀, female; ↑, increased; ↓, decreased; ↔, unchanged.