The postnatal window is critical for the development of sex-specific metabolic and gut microbiota outcomes in offspring

Personalized modeling of gut microbiome metabolism throughout the first year of life

BACKGROUND

Early-life exposures including diet, and the gut microbiome have been proposed to predispose infants towards multifactorial diseases later in life. Delivery via Cesarian section disrupts the establishment of the gut microbiome and has been associated with negative long-term outcomes. Here, we hypothesize that Cesarian section delivery alters not only the composition of the developing infant gut microbiome but also its metabolic capabilities. To test this, we developed a metabolic modeling workflow targeting the infant gut microbiome.

METHODS

The AGORA2 resource of human microbial genome-scale reconstructions was expanded with a human milk oligosaccharide degradation module. Personalized metabolic modeling of the gut microbiome was performed for a cohort of 20 infants at four time points during the first year of life as well as for 13 maternal gut microbiome samples.

RESULTS

Here we show that at the earliest stages, the gut microbiomes of infants delivered through Cesarian section are depleted in their metabolic capabilities compared with vaginal delivery. Various metabolites such as fermentation products, human milk oligosaccharide degradation products, and amino acids are depleted in Cesarian section delivery gut microbiomes. Compared with maternal gut microbiomes, infant gut microbiomes produce less butyrate but more L-lactate and are enriched in the potential to synthesize B-vitamins.

CONCLUSIONS

Our simulations elucidate the metabolic capabilities of the infant gut microbiome demonstrating they are altered in Cesarian section delivery at the earliest time points. Our workflow can be readily applied to other cohorts to evaluate the effect of feeding type, or maternal factors such as diet on host-gut microbiome inactions in early life.

Maternal high fat diet induces circadian clock-independent endocrine alterations impacting the metabolism of the offspring

Maternal obesity has long-term effects on offspring metabolic health. Among the potential mechanisms, prior research has indicated potential disruptions in circadian rhythms and gut microbiota in the offspring. To challenge this hypothesis, we implemented a maternal high fat diet regimen before and during pregnancy, followed by a standard diet after birth. Our findings confirm that maternal obesity impacts offspring birth weight and glucose and lipid metabolisms. However, we found minimal impact on circadian rhythms and microbiota that are predominantly driven by the feeding/fasting cycle. Notably, maternal obesity altered rhythmic liver gene expression, affecting mitochondrial function and inflammatory response without disrupting the hepatic circadian clock. These changes could be explained by a masculinization of liver gene expression similar to the changes observed in polycystic ovarian syndrome. Intriguingly, such alterations seem to provide the first-generation offspring with a degree of protection against obesity when exposed to a high fat diet.

Sexual dimorphism in the gut microbiota and sexual dimorphism in chronic diseases: Association or causation?

Understanding the sexual dimorphism in diseases is essential to investigate the pathogenesis of some chronic diseases (e.g., autoimmune diseases, etc). The gut microbiota has been found to show a notable impact on the pathology of several chronic diseases in recent years. Intriguingly, the composition of the gut microbiota varies between sexes. Here, we reviewed 'facts and fiction' regarding sexual dimorphism in chronic diseases and sexual dimorphism in the gut microbiota respectively. The association and causative relationship between them aiming to elucidate the pathological mechanisms of sexual dimorphism in chronic diseases were further explored. The development of gender-special food products based on the sexual dimorphism in the gut microbiota were recommended, which would be beneficial to facilitating the personalized treatment.

Maternal High-Fat Diet Results in Long-Term Sex-Specific Alterations to Metabolic and Gut Microbial Diurnal Oscillations in Adult Offspring

SCOPE

Circadian rhythms profoundly impact metabolism and the gut microbiota. A maternal high-fat diet (HFD) exerts effects on the metabolic syndrome of adult offspring in a sex-specific manner, the underlying mechanisms, however, remain unclear.

METHODS AND RESULTS

Female mice are fed an HFD and raise their offspring on a standard chow diet until 24 weeks. The glucose tolerance, insulin sensitivity, and diurnal rhythms of serum metabolic profiles are assessed in male and female adult offspring. Simultaneously, 16S rRNA is applied to characterize gut microbiota diurnal rhythms. The study finds that maternal HFD tends to deteriorate glucose tolerance and impairs insulin sensitivity in male offspring, but not female offspring, which can be associated with the circadian alterations of serum metabolic profiles in male offspring. As expected, maternal HFD sex-specifically alters diurnal rhythms of the gut microbiota, which exhibits putative associations with metabolic profiles in males.

CONCLUSIONS

The present study identifies the critical role of gut microbiota diurnal rhythms in triggering sex-biased metabolic diurnal rhythms in response to maternal HFD, at least in part. As early life may be a critical window for preventing metabolic diseases, these findings provide the basis for developing chronobiology applications targeting the gut microbiota to combat early metabolic alterations, especially in males.

Microbial modulation via cross-fostering prevents the effects of pervasive environmental stressors on microglia and social behavior, but not the dopamine system

Environmental toxicant exposure, including air pollution, is increasing worldwide. However, toxicant exposures are not equitably distributed. Rather, low-income and minority communities bear the greatest burden, along with higher levels of psychosocial stress. Both air pollution and maternal stress during pregnancy have been linked to neurodevelopmental disorders such as autism, but biological mechanisms and targets for therapeutic intervention remain poorly understood. We demonstrate that combined prenatal exposure to air pollution (diesel exhaust particles, DEP) and maternal stress (MS) in mice induces social behavior deficits only in male offspring, in line with the male bias in autism. These behavioral deficits are accompanied by changes in microglial morphology and gene expression as well as decreased dopamine receptor expression and dopaminergic fiber input in the nucleus accumbens (NAc). Importantly, the gut-brain axis has been implicated in ASD, and both microglia and the dopamine system are sensitive to the composition of the gut microbiome. In line with this, we find that the composition of the gut microbiome and the structure of the intestinal epithelium are significantly shifted in DEP/MS-exposed males. Excitingly, both the DEP/MS-induced social deficits and microglial alterations in males are prevented by shifting the gut microbiome at birth via a cross-fostering procedure. However, while social deficits in DEP/MS males can be reversed by chemogenetic activation of dopamine neurons in the ventral tegmental area, modulation of the gut microbiome does not impact dopamine endpoints. These findings demonstrate male-specific changes in the gut-brain axis following DEP/MS and suggest that the gut microbiome is an important modulator of both social behavior and microglia.

Crosstalk between gut microbiota and renal ischemia/reperfusion injury

Renal ischemia-reperfusion injury (IRI) is the main cause of acute kidney injury and the cause of rapid renal dysfunction and high mortality. In recent years, with the gradual deepening of the understanding of the intestinal flora, exploring renal IRI from the perspective of the intestinal flora has become a research hotspot. It is well known that the intestinal flora plays an important role in maintaining human health, and dysbiosis is the change in the composition and function of the intestinal tract, which in turn causes intestinal barrier dysfunction. Studies have shown that there are significant differences in the composition of intestinal flora before and after renal IRI, and this difference is closely related to the occurrence and development of renal IRI and affects prognosis. In addition, toxins produced by dysregulated gut microbes enter the bloodstream, which in turn exacerbates kidney damage. This article reviews the research progress of intestinal flora and renal IRI, in order to provide new treatment ideas and strategies for renal IRI.