Why what we spray on our food might be quietly rewiring our hormones.
New research is shining a light on something that’s been hiding in plain sight — the trillions of microbes living in your gut aren’t just digesting your lunch. They’re actively managing your hormones.
A recent scientific review published in npj Biofilms and Microbiomes (24 June 2026) confirmed that gut bacteria play a central role in regulating oestrogen — influencing how much of it circulates in the body, how it behaves, and whether it tips the balance toward serious illness, including hormone-driven cancers like breast and endometrial cancer.
It’s a significant finding. And for those of us watching what goes onto our food and into our bodies, it raises a question that has yet to be directly addressed in the scientific literature.
Your Gut Microbiome Regulates Oestrogen — Here’s How
Inside your digestive system lives a community of bacteria known as the estrobolome — a subset of gut microbes that control how oestrogen is processed and recycled in the body.
These bacteria produce enzymes that can reactivate oestrogen, essentially returning it to circulation after the body has tried to clear it. Too much reactivation, and oestrogen levels creep higher than they should. Over time, that excess exposure is linked to cancer risk.
The review goes further, describing the gut microbiome as an “active endocrine partner” — not just a passive recycler, but a living system that shapes hormone signalling throughout the body.
When that microbial community is disrupted — a state called dysbiosis — the consequences extend well beyond digestion. Chronic low-grade inflammation sets in. Protective metabolites disappear. Hormonal balance shifts. The body’s natural defences quietly erode.
Importantly, the review itself does not investigate glyphosate. Instead, it focuses on understanding how the gut microbiome influences hormone regulation and cancer biology. The question explored here is whether existing research on glyphosate and the gut microbiome may intersect with those newly described mechanisms.
Glyphosate Is a Patented Antimicrobial. What Does That Mean for Your Gut?
Here’s the part you won’t find in that scientific review — but perhaps should.
Glyphosate, the world’s most widely used herbicide and the active ingredient in Roundup, was originally patented not just as a herbicide, but as an antimicrobial.
That matters.
If glyphosate selectively disrupts gut bacteria — and there is a growing body of evidence suggesting it does — then it has the potential to throw the very microbial systems described in this review into disarray.
Think about what that could mean:
- Beneficial bacteria involved in oestrogen metabolism could be reduced
- Protective metabolites — like those produced from plant compounds in our food — are no longer made
- Chronic inflammation may become more likely
- The hormonal environment could shift in ways that may favour disease
The review describes what researchers believe may occur when the microbiome becomes disrupted. The glyphosate question is simply this: are we disrupting it — every day, on an industrial scale?
Glyphosate Residues in New Zealand Food: Daily Exposure, Cumulative Risk
Glyphosate residues are regularly detected in a range of foods worldwide, including cereals, pulses, legumes and processed grain products. In New Zealand, independent testing by No More Glyphosate NZ has identified residues in some bread and breakfast cereal products, while others have tested below laboratory reporting limits.
We are not talking about one-off exposures. We are talking about daily, cumulative contact with a substance that also holds patents for antimicrobial activity.
What the Research Says — and What It Deliberately Avoids
To be fair, the researchers behind the estrobolome review are cautious. They acknowledge that most human studies show associations rather than proven cause and effect. They call for more longitudinal research, standardised methods, and clinical trials before microbiome-based therapies become routine.
That caution is scientifically appropriate.
But it also means the researchers were not looking at environmental disruptors like glyphosate. They were focused on the mechanism — what the microbiome does, and how disrupting it relates to cancer.
We’re simply joining two bodies of evidence that have not yet been placed side by side.
The Precautionary Principle: How Much Evidence Is Enough?
Science is increasingly telling us that the gut microbiome is a hormonal gatekeeper. Disrupt it, and you may disrupt the entire endocrine ecosystem it supports.
Glyphosate is a patented antimicrobial, sprayed on our food, detected in our bodies, and present at residue levels in much of what we eat.
The researchers who wrote this review would likely say more evidence is needed before drawing firm conclusions.
We would simply ask: how much more evidence do we need before we apply the precautionary principle?
The gut microbiome took millions of years to evolve. We’ve used glyphosate in agriculture for less than fifty years.
This article draws on a review published in npj Biofilms and Microbiomes (June 2026): "Beyond estrobolome 1.0: unravelling endocrine-microbiome axis as a driver and therapeutic target in hormone-driven cancers."
No More Glyphosate NZ advocates for the application of the precautionary principle in the regulation of glyphosate in New Zealand.
Further Reading
This article connects two bodies of science that don’t often appear in the same conversation. But it didn’t emerge from nowhere — it reflects more than a year of research, testing, and writing that has been building toward exactly this kind of question.
If something in this piece made you stop and think, the articles below will take you further.
On glyphosate and the gut microbiome
We’ve written about the gut connection before. The Missing Piece in the Glyphosate Debate: Your Gut Microbiome explores how microbiome research is beginning to intersect with glyphosate science — and why that intersection matters.
For a more specific example of what microbial disruption can look like in practice, Could Glyphosate Be Killing the Rothia Bacteria That Protect You From Celiac Disease? follows the science on one specific bacterial species and a disease that has risen nearly tenfold in New Zealand over three decades.
On children and vulnerable populations
Glyphosate, Children’s Health, and the Questions Regulators Aren’t Asking features Dr Michelle Perro, a paediatrician with 45 years of clinical experience, on gut disorders, environmental exposures, and what she believes is being overlooked.
On residues in the food we eat every day
This article mentions bread, oats, and everyday foods. We’ve tested them. Glyphosate in New Zealand Bread: Why Some Loaves Test Clean and Glyphosate in Supermarket Bread: September 2025 Test Results show what independent testing in New Zealand actually finds.
On regulatory accountability
If Canada Can Continuously Monitor Glyphosate, Why Can’t New Zealand? and Who Holds Regulators Accountable When the Science Changes? ask the harder questions about who is watching, and whether New Zealand’s oversight is fit for purpose.
The science on glyphosate and human health is not settled — but it is moving. New connections are being made, new mechanisms identified, and new questions asked that weren’t being asked five years ago.
What isn’t moving fast enough is the regulatory response.
We’ll keep following the evidence, wherever it leads. If you’d like to follow it with us, sign up for our newsletter — and if you believe this kind of independent research matters, consider supporting our testing programme.
Image Source & Attribution
The feature image on this page was created using AI-assisted image generation based on a concept developed by No More Glyphosate NZ and refined in Canva for publication.
