Constant light exposure alters gut microbiota and short-/medium-chain fatty acids and aggravates PCOS-like traits in HFD-fed rats

Melatonin-mediated corrective changes in gut microbiota of experimentally chronodisrupted C57BL/6J mice

Chronic consumption of a high-calorie diet coupled with an altered sleep-wake cycle causes disruption of circadian clock that can impact the gut microbiome leading to metabolic syndrome and associated diseases. Herein, we investigate the effects of a high fat high fructose diet (H) alone or in combination with photoperiodic shifts induced chronodisruption (CD) on gut microbiota of C57BL/6J male mice. Further, the merits of daily evening intraperitoneal administration of melatonin in restoring gut microbiota are studied herein. Experimental groups viz. H, CD and HCD mice recorded higher levels of serum pro-inflammatory cytokines (TNF-α and IL-6) and lower levels of the anti-inflammatory cytokine, IL-10. These findings correlate with a concomitant increase in the transcripts of TLR4, TNF-α, and IL-6 in small intestine of the said groups. A decrement in mRNA levels of Ocln, ZO-1 and Vdr in these groups implied towards an altered gut permeability. These results were in agreement with the observed decrement in percentage abundance of total gut microflora and Firmicutes: Bacteroidetes (F/B) ratio. Melatonin administration accounted for lower-level inflammation (serum and gut) along with an improvement in gut permeability markers. The total abundance of gut microflora and F/B ratio showed an improvement in all the melatonin-treated groups and the same is the highlight of this study. Taken together, our study is the first to report perturbations in gut microbiota resulting due to a combination of photoperiodic shifts induced CD and a high fat high calorie diet-induced lifestyle disorder. Further, melatonin-mediated rejuvenation of gut microbiome provides prima facie evidence of its role in improving gut dysbiosis that needs a detailed scrutiny.

Unraveling the complexity of polycystic ovary syndrome with animal models

Polycystic ovary syndrome (PCOS) is a highly familial and heritable endocrine disorder. Over half of the daughters born to women with PCOS may eventually develop their own PCOS-related symptoms. Progress in the treatment of PCOS is currently hindered by the complexity of its clinical manifestations and incomplete knowledge of its etiopathogenesis. Various animal models, including experimentally induced, naturally occurring, and spontaneously arising ones, have been established to emulate a wide range of phenotypical and pathological traits of human PCOS. These studies have led to a paradigm shift in understanding the genetic, developmental, and evolutionary origins of this disorder. Furthermore, emerging evidence suggests that animal models are useful in evaluating state-of-the-art drugs and treatments for PCOS. This review aims to provide a comprehensive summary of recent studies of PCOS in animal models, highlighting the power of these disease models in understanding the biology of PCOS and aiding high-throughput approaches.

Associations of nighttime light exposure during pregnancy with maternal and neonatal gut microbiota: A cohort study

BACKGROUND

Nighttime light (NTL) pollution has been reported as a risk factor for human health. However, the relationship between NTL and gut microbiota has not been reported in pregnant women and neonates. This study was conducted to investigate the relationship between NTL and gut microbial diversity and composition in mothers and their neonates.

METHODS

This study analyzed 44 mothers and 28 newborns. The composition of gut microbiota was evaluated using 16S rRNA V3-V4 sequencing. The monthly mean NTL exposure during pregnancy was respectively calculated based on each participant's residential address (NTLpoint) and a concentric 1 km radius buffer zone around their address (NTL1000m). The relationships between NTL exposure and gut microbiota of mothers and newborns were assessed using generalized linear models.

RESULTS

NTL exposure during pregnancy was not associated with alpha diversity of mothers or neonates. For mothers, results revealed that after adjusting for covariates, NTLpoint was negatively correlated with Prevotella_2 (p = 0.004, FDR-adjusted p = 0.030) and norank_o__Gastranaerophilales (p = 0.018, FDR-adjusted p = 0.049) at the genus level. In addition, Lachnospira (p = 0.036, FDR-adjusted p = 0.052) and Coprococcus_3 (p = 0.025, FDR-adjusted p = 0.052) were positively correlated with NTLpoint. The association between Coprococcus_3 (p = 0.01, FDR-adjusted p = 0.046) and NTLpoint persisted even after controlling for covariates. For neonates, Thauera was positively associated with NTLpoint (p = 0.015) and NTL1000m (p = 0.028), however, after adjusting for covariates and FDR correction, Thauera was not significantly associated with NTLpoint and NTL1000m.

CONCLUSIONS

This study found that NTL exposure was associated with maternal gut microbiota composition. Our findings provide a foundation for the potential impact of NTL exposure on maternal gut microbiota from a microbiological perspective. More population-based validation of the effects of NTL exposure on human gut microbiota is needed in future.

Central blockage of sympathetic nerves inhibits the abnormal vital signs and disturbance of the gut microbiota caused by continuous light exposure

Background

Continuous light exposure increases sympathetic excitation in rats, leading to hypertension, left ventricular hypertrophy, and fibrosis. This study was aimed to investigate whether continuous light exposure causes destabilization of vital signs and gut microbiota (GM) in Sprague Dawley (SD) rats and whether clonidine hydrochloride (CH), a central sympathetic depressant drug, could prevent these changes.

Methods

Eight-week-old male SD rats were divided into three groups with different interventions for 14 weeks: control group (CG), 2-mL pure water gavaged daily while on a normal 12-h light/dark cycle; continuous illumination group (CI), 2-mL pure water gavaged daily while receiving continuous exposure to light (300 lx); and drug administration group (DA), CH (10 μg/kg) gavaged daily while receiving continuous exposure to light (300 lx).

Results

The results showed that blood pressure, heart rate, and body weight were significantly higher in the CI group than in the CG and DA groups (P < 0.05). Moreover, the Shannon index was higher in the DA group than in the CI group (P = 0.012). The beta diversity index in the CG group was significantly higher in the CI group (P = 0.039). The pairwise comparison results of the linear discriminant analysis effect size showed that Oscillospirales were enriched in the DA group, whereas the Prevotellaceae lineage (family level) > Prevotella (genus level) > Prevotellaceae_bacterium (species level) were enriched in the CI group. The Muribaculaceae family was more abundant in the CG group than in the CI group.

Conclusion

Sympathetic nerve inhibition restored the abnormal vital signs and GM changes under continuous light exposure.

Association between mobile phone addiction, sleep disorder and the gut microbiota: a short-term prospective observational study

Bidirectional communication between the gut microbiota and the brain has sparked interest in exploring the link between mobile phone addiction (MPA) and sleep disorders (SD) in microbiome research. However, investigating the role of gut microbiota in this relationship using animal models presents challenges due to the unique nature of MPA, and human research in this area is scarce. We recruited 99 healthy college students to evaluate the gut microbiome using 16S rRNA gene amplicon sequencing and assess MPA and SD at baseline and after a two-month follow-up. Multiple covariate-adjusted statistical models, including linear regression, permutational multivariate analysis of variance and so on, were employed to determine microbiome associations with MPA at baseline and changes in SD at follow-up. Our findings revealed negative associations between MPA and three alpha diversity metrics, along with alterations in bacterial composition. MPA showed negative associations with the relative abundance of Bacteroidetes, while displaying positive associations with Actinobacteria and Bifidobacteriales. Conversely, Actinobacteria exhibited a negative association with increased SD. This study has established a significant link between MPA and a decrease in the alpha diversity of the gut microbiota. Actinobacteria was associated with MPA and SD, respectively. Additional investigation is needed to fully comprehend the relationship between comorbid behavioral disorders and the gut microbiota.