Western diet-induced shifts in the maternal microbiome are associated with altered microRNA expression in baboon placenta and fetal liver

Abstract

Maternal consumption of a high-fat, Western-style diet (WD) disrupts the maternal/infant microbiome and contributes to developmental programming of the immune system and nonalcoholic fatty liver disease (NAFLD) in the offspring. Epigenetic changes, including non-coding miRNAs in the fetus and/or placenta may also underlie this risk. We previously showed that obese nonhuman primates fed a WD during pregnancy results in the loss of beneficial maternal gut microbes and dysregulation of cellular metabolism and mitochondrial dysfunction in the fetal liver, leading to a perturbed postnatal immune response with accelerated NAFLD in juvenile offspring. Here, we investigated associations between WD-induced maternal metabolic and microbiome changes, in the absence of obesity, and miRNA and gene expression changes in the placenta and fetal liver. After ~8-11 months of WD feeding, dams were similar in body weight but exhibited mild, systemic inflammation (elevated CRP and neutrophil count) and dyslipidemia (increased triglycerides and cholesterol) compared with dams fed a control diet. The maternal gut microbiome was mainly comprised of Lactobacillales and Clostridiales, with significantly decreased alpha diversity (P = 0.0163) in WD-fed dams but no community-wide differences (P = 0.26). At 0.9 gestation, mRNA expression of IL6 and TNF in maternal WD (mWD) exposed placentas trended higher, while increased triglycerides, expression of pro-inflammatory CCR2, and histological evidence for fibrosis were found in mWD-exposed fetal livers. In the mWD-exposed fetus, hepatic expression levels of miR-204-5p and miR-145-3p were significantly downregulated, whereas in mWD-exposed placentas, miR-182-5p and miR-183-5p were significantly decreased. Notably, miR-1285-3p expression in the liver and miR-183-5p in the placenta were significantly associated with inflammation and lipid synthesis pathway genes, respectively. Blautia and Ruminococcus were significantly associated with miR-122-5p in liver, while Coriobacteriaceae and Prevotellaceae were strongly associated with miR-1285-3p in the placenta; both miRNAs are implicated in pathways mediating postnatal growth and obesity. Our findings demonstrate that mWD shifts the maternal microbiome, lipid metabolism, and inflammation prior to obesity and are associated with epigenetic changes in the placenta and fetal liver. These changes may underlie inflammation, oxidative stress, and fibrosis patterns that drive NAFLD and metabolic disease risk in the next generation.

Vertical Transfer of Maternal Gut Microbes to Offspring of Western Diet-Fed Dams Drives Reduced Levels of Tryptophan Metabolites and Postnatal Innate Immune Response

“…Least absolute shrinkage and selection operator (LASSO) regularization [ 49 ] was used for variable selection to compare serum metabolomics results with gut microbiota genera as described previously [ 46 ] using the R package glmnet [ 50 ]. The serum metabolomics data were log2 transformed, and microbiota count data were center log-ratio transformed after excluding genera using the criteria described above.…”

Potassium Magnesium Citrate Is Superior to Potassium Chloride in Reversing Metabolic Side Effects of Chlorthalidone

“…During phase 4, each subject was randomized to receive either KCl powder containing 40 mEq KCl/day (n=31) versus KMgCit (IND 116 208) powder containing 40 mEq K, 20 mEq Mg, and 74 mEq citrate/day (n=29) in a double-blinded manner. Additional details regarding each study phase, biochemical, [12][13][14] hormonal, 15 muscle-free Mg concentration, 16,17 side effects, 9 and hepatic fat measurements, 18 are provided in the Supplemental Material.…”

Vertical Transfer of Maternal Gut Microbes to Offspring of Western Diet-Fed Dams Drives Reduced Levels of Tryptophan Metabolites and Postnatal Innate Immune Response

“…Cecal contents were collected from mice following euthanasia and stored at -80°C until DNA extraction and 16S rRNA gene sequencing were performed as described previously [28,45]. Microbiome sequencing data was processed using QIIME2 2021.8 software as previously described [46]. Microbiota count data were used to calculate alpha (Shannon) and beta (Bray-Curtis) diversity in R (https://www.r-project.org/) using the vegan package [47].…”

“…Least absolute shrinkage and selection operator (LASSO) regularization [49] was used for variable selection to compare serum metabolomics results with gut microbiota genera as described previously [46] using the R package glmnet [50]. The serum metabolomics data were log2 transformed and microbiota count data were center log-ratio transformed after excluding genera using criteria described above.…”