Transgenerational Exposure to Plastics-Derived Endocrine-Disrupting Bisphenol A and Its Analogs on Male Infertility: Impact of Gut Dysbiosis and Epigenetic Regulation

A narrative review argues BPA harms male fertility via gut dysbiosis and epigenetic marks — but admits the transgenerational evidence is provisional at best

Journal: Frontiers in Endocrinology | Published: 2026-05-08 | Type: Narrative Review | PMID: 42181199 Authors: Basak S, Varma S, Nag S (ICMR–National Institute of Nutrition, India); Duttaroy AK (University of Oslo, Norway) Funding/COI: Funding not disclosed. Authors declared no commercial or financial conflicts of interest.

Summary

This narrative review synthesizes in vivo evidence that BPA, an estrogen-mimicking plasticizer, disrupts male fertility through two interacting pathways: gut dysbiosis (altered microbiome composition and metabolites) and epigenetic modification of germ cells. The proposed mechanism runs from BPA ingestion → gut microbiome disruption → systemic inflammation and altered hormone signaling → impaired spermatogenesis and sperm quality. The authors then extend this to transgenerational inheritance, arguing BPA-induced epigenetic marks in germ cells may persist to F3 (great-grandchildren of the exposed individual). Critically, the authors themselves caveat that this last claim is provisional and that causal inference is premature.

Claims

• BPA exposure in vivo alters gut microbial composition, diversity, and metabolites, producing dysbiosis with reduced microbial diversity and enrichment of obesity-linked taxa
• BPA-induced gut dysbiosis is proposed to regulate gonadal hormone homeostasis, testicular structure, and sperm quality via altered metabolites, oxidative stress, autophagy, and pro-inflammatory signaling
• BPA can enter the nucleus and modify gene promoter methylation similarly to estradiol, altering transcription of target genes
• BPA-induced epigenetic changes have been observed in F3 germ cells (two generations beyond direct exposure) in animal models, suggesting transgenerational inheritance via differentially methylated regions (DMRs)
• Histone modifications (H3K9me3, H3K27me3) as a mechanism of transgenerational inheritance are described as "insufficiently substantiated"
• The review explicitly states that causal inference for BPA-driven germline epigenetic transmission "remains premature"

Study Quality

This is a narrative review, the lowest tier of synthesis evidence. Unlike systematic reviews, narrative reviews lack a registered protocol, systematic search strategy, or PRISMA-style inclusion/exclusion criteria — meaning the authors selected studies that fit their hypothesis without a reproducible method for what was included or excluded. The underlying evidence base is predominantly animal (in vivo) studies; direct human data on BPA, gut dysbiosis, and transgenerational epigenetic inheritance of male infertility is sparse to nonexistent.

The mechanistic chain proposed — BPA → dysbiosis → epigenetic germ cell marks → heritable infertility across three generations — is plausible in parts but unvalidated as a complete pathway in humans. The review's own conclusion section honestly flags that DMR evidence in F3 germ cells is preliminary, that histone modification inheritance through spermatogenesis faces major mechanistic barriers (histone-protamine transition, post-fertilization reprogramming), and that F3-resolved, locus-level chromatin profiling in humans does not yet exist.

Red Flags

• Narrative review design: no systematic search, no PRISMA, no inclusion criteria — selection bias baked in
• Funding not disclosed despite institutional affiliations; raises questions without answering them
• Transgenerational claims rest almost entirely on animal model data; the review acknowledges human evidence is absent
• Authors state causal germline transmission conclusions are "provisional" and "premature" — this is the headline claim of the paper
• The gut dysbiosis → epigenetic transmission feedback loop is speculative and the review acknowledges it "needs to be examined further"
• Heavy use of hedged language ("suggested," "may," "can") throughout — appropriate, but means few hard conclusions are warranted

Strengths

• Authors are unusually candid about the limits of their own evidence; the conclusion section reads as honest rather than promotional
• The proposed gut-reproductive axis is mechanistically coherent and identifies a legitimate gap in the literature
• Covers BPA analogs (bisphenol S, F, etc.) as the regulatory response to BPA has driven substitution toward poorly-studied alternatives
• Draws attention to a plausible multi-generational harm at a time when human sperm counts are declining for reasons that remain incompletely explained

Verdict

Read the conclusion before the abstract — it's more honest. This paper proposes an interesting and mechanistically plausible pathway from ubiquitous plasticizer exposure to heritable male infertility, but the transgenerational epigenetic claims, which are the paper's most striking contribution, are acknowledged by the authors themselves to be premature. The underlying evidence is animal-model-heavy, and the narrative review format means you can't trust that the cited studies represent the full picture. Worth reading if you're mapping the hypothesis space around environmental EDCs and male fertility; not worth citing as evidence that BPA causes transgenerational infertility in humans, because the authors are clear that no such evidence currently exists.