Bacillus amyloliquefaciens SC06 attenuated high-fat diet induced anxiety-like behavior and social withdrawal of male mice by improving antioxidant capacity, intestinal barrier function and modulating intestinal dysbiosis

Stevioside Ameliorates Prenatal Obesity Induced Postpartum Depression: The Potential Role of Gut Barrier Homeostasis

SCOPE

Postpartum depression and cognitive impairment are the common complications of prenatal obesity. Stevioside is a non-nutritive natural sweetener with antioxidant and anti-inflammatory. However, its effects on depression behaviors and cognitive impairment induced by a high-fat diet (HFD) remain unclear.

METHODS AND RESULTS

An 8-week HFD is used to establish a prenatal obesity model in female C57BL/6J mice to explore the improvement effects of stevioside (0.5 mg mL-1 in drinking water) on maternal depression and cognitive dysfunction after weaning. The results demonstrated that stevioside improves behavioral performance of obese maternal mice, and inhibits neuronal damage and 5-hydroxytryptamine (5-HT) abnormality induced by HFD. In addition, stevioside inhibits oxidative stress by reducing malondialdehyde (MDA) and increasing superoxide dismutase (SOD) and glutathione (GSH) activities in the brains of obese maternal mice. Additionally, stevioside improves gut barrier integrity and prevented lipopolysaccharide (LPS) extravasation, and alleviates neuroinflammation. Correlation analysis shows that gut barrier and serum LPS are closely related to behavioral performance and brain biochemical indicators.

CONCLUSION

Stevioside is capable to prevent prenatal obesity-induced cognitive and mood disorders by restoring intestinal barrier damage and inhibiting inflammation.

The gut virome is associated with stress-induced changes in behaviour and immune responses in mice

The microbiota-gut-brain axis has been shown to play an important role in the stress response, but previous work has focused primarily on the role of the bacteriome. The gut virome constitutes a major portion of the microbiome, with bacteriophages having the potential to remodel bacteriome structure and activity. Here we use a mouse model of chronic social stress, and employ 16S rRNA and whole metagenomic sequencing on faecal pellets to determine how the virome is modulated by and contributes to the effects of stress. We found that chronic stress led to behavioural, immune and bacteriome alterations in mice that were associated with changes in the bacteriophage class Caudoviricetes and unassigned viral taxa. To determine whether these changes were causally related to stress-associated behavioural or physiological outcomes, we conducted a faecal virome transplant from mice before stress and autochthonously transferred it to mice undergoing chronic social stress. The transfer of the faecal virome protected against stress-associated behaviour sequelae and restored stress-induced changes in select circulating immune cell populations, cytokine release, bacteriome alterations and gene expression in the amygdala. These data provide evidence that the virome plays a role in the modulation of the microbiota-gut-brain axis during stress, indicating that these viral populations should be considered when designing future microbiome-directed therapies.