# Distinct gut flora profile induced by postnatal trans-fat diet in gestationally bisphenol A-exposed rats

## TL;DR

This study shows that a postnatal trans-fat diet in rats previously exposed to bisphenol A during pregnancy significantly alters gut microbiome diversity and function, potentially leading to future metabolic issues.

## Contribution

The study reveals how postnatal trans-fat diet, not prenatal BPA exposure, primarily shapes gut microbiome diversity and function in offspring.

## Key findings

- TFD offspring showed significantly lower alpha diversity compared to ND offspring (p<0.001–p<0.05).
- Microbiome composition of TFD groups was distinctly different from ND groups, as shown by beta diversity and clustering analyses.
- Predictive functional analysis showed altered metabolic pathways in TFD offspring compared to ND groups.

## Abstract

There has been much evidence showing the repercussions of prenatal bisphenol A (BPA) exposure with a postnatal high fat-diet (HFD) on offspring’s health. However, the information on how the interaction between these two variables affects the gut microbiome is rather limited. Hence, we investigated the impact of a postnatal trans fat diet (TFD) on the gut microbiome of offspring exposed to BPA during the prenatal period in an animal model. Pregnant rats were divided into 5 mg/kg/day BPA, vehicle Tween80 (P80) or control (CTL) drinking water until delivery (N = 6 per group). Then, weaned male pups were further subdivided into three normal diet (ND) groups (CTLND, P80ND, and BPAND) and three TFD groups (CTLTFD, P80TFD, and BPATFD) (n = 6 per group). 180–250 g of faecal samples were collected on days 50 and 100 to assess the composition of the offspring’s intestinal flora using next-generation sequencing. The alpha diversity indices of TFD offspring with and without BPA were markedly lower than their ND counterparts (p<0.001–p<0.05). The beta diversity, hierarchical cluster and network analyses of the offspring’s microbiome demonstrated that the microbiome species of the TFD group with and without BPA were distinctly different compared to the ND group. Consistently, TFD and ND offspring pairings exhibited a higher number of significantly different species (p<0.0001–p<0.05) compared to those exposed to prenatal BPA exposure and different life stages comparisons, as shown by the multivariate parametric analysis DESeq2. Predictive functional profiling of the offspring’s intestinal flora demonstrated altered expressions of genes involved in metabolic pathways. In summary, the gut flora composition of the rat offspring may be influenced by postnatal diet instead of prenatal exposure to BPA. Our data indicate the possibility of perturbed metabolic functions and epigenetic modifications, in offspring that consumed TFD, which may theoretically lead to metabolic diseases in middle or late adulthood. Further investigation is necessary to fully understand these implications.