If your Microbiome could vote, it wouldn't choose Ultra-Processed Populism

Imagine a general election inside your gut.

If Your Microbiome Could Vote, It Wouldn’t Choose Ultra-Processed Populism

Imagine a general election inside your gut.

Trillions of microscopic citizens march shoulder to shoulder, waving placards that read “More Fibre!”, “We Demand Complex Carbs!” and “Less Sugar, More Roughage!” It’s noisy, unruly, and deeply political. And unlike most elections, the outcome would be remarkably clear.

If your microbiome had a vote, your plate would look very different.

You Are Not Just You

We like to think of ourselves as autonomous individuals, but biologically speaking, that’s a flattering fiction. Each of us is an ecosystem: human cells living alongside trillions of microbes that have co-evolved with us for hundreds of thousands of years. These microbes are not passive squatters. They digest food we can’t, produce vitamins we rely on, regulate our immune system, and even communicate directly with our brain.

Your genes provide the blueprint — your genotype — but what actually shows up in real life, your phenotype, is shaped by a constant negotiation between genes, environment, behaviour, and food. Diet is not just fuel; it is information. It alters gene expression, reshapes metabolic pathways, and reorganises the microbial communities that live within us.

As explored in Food and Us: The Incredible Story of How Food Shapes Humanity, https://thebookfoodandus.com/ , our biology and our food systems have always evolved together. The problem is that food now evolves far faster than we do.

Ancient Genes, Modern Chaos

Many of our genes evolved under conditions that no longer exist. Variants that once helped our ancestors survive periods of famine — by efficiently storing sugar as fat — now operate in an environment of permanent abundance. What was once an evolutionary advantage has become a metabolic liability.

This mismatch helps explain why diseases of civilisation — obesity, type 2 diabetes, cardiovascular disease, autoimmune disorders, osteoporosis, and some cancers — are so common in industrialised societies and so rare in hunter-gatherer and non-westernised populations.

The food environment has changed faster than our biology can adapt. And our microbiome is caught in the crossfire.

The Addictive Food Debate (Spoiler: It’s Real)

There is growing evidence that an addictive-eating phenotype exists. Ultra-processed foods (UPFs), particularly those that combine refined carbohydrates with sugar and added fats, appear to hijack the brain’s reward system in a way strikingly similar to nicotine.

These foods increase dopamine in the striatum by 150–200 percent — a magnitude comparable to smoking. They trigger cravings, compulsive use, and continued consumption even in the face of clear health consequences. If this sounds less like “poor willpower” and more like pharmacology, that’s because it is.

When a food system is engineered for maximal reward and minimal nutrition, framing overconsumption as purely a matter of personal choice becomes scientifically untenable.

Enter the Microbiome — and Its Energy Partner

While genes get most of the attention, mitochondria quietly run the show. These tiny organelles — inherited exclusively from our mothers — produce ATP, the energy currency that powers every thought, heartbeat, and muscle contraction.

Here’s the twist: your microbiome communicates directly with your mitochondria.

Gut microbes influence how efficiently we extract energy from food, how inflammation is regulated, and how metabolism functions at a cellular level. This microbial-mitochondrial dialogue is fundamental to health — and it is exquisitely sensitive to diet.

From birth, the microbiome begins shaping us. Vaginal delivery bathes newborns in beneficial bacteria, kick-starting immune development and brain maturation. By the age of three, the core microbiome is largely established — shaped far more by environment, geography, and diet than by genetics.

Then, over time, ageing, illness, antibiotics, and poor diet begin to erode its diversity.

Fibre: The Policy Platform Your Gut Supports

If there were a microbiome manifesto, fibre would be its central plank. Dietary fibre cannot be digested by human enzymes. Instead, it is fermented by gut bacteria, producing short-chain fatty acids (SCFAs) that lower colonic pH, suppress harmful microbes, regulate immune function, and improve metabolic health. Fibre slows gastric emptying, increases satiety, and plays a critical role in appetite regulation.

Remove fibre from the diet, and microbial diversity collapses. Immune signaling falters. Inflammation rises. The gut-brain axis — the bidirectional communication network linking digestion, mood, and cognition — becomes distorted.

That “gut feeling” you get? The butterflies? That’s not metaphor. That’s biology.

Beyond Reductionism

As Giulia Enders reminds us in Gut, The Inside Story of Our Body's Most Underrated Organ, the human body is not a simple cause-and-effect machine. The brain, the gut, microbes, mitochondria, and food interact in multiple dimensions. You cannot isolate one part without distorting the whole.

Which brings us back to the election in your gut.

Your microbiome is voting every day — not with ballots, but with metabolites, neurotransmitters, and immune signals. It votes for whole foods, plants, fibre, and complexity. It votes against ultra-processed shortcuts that promise pleasure but deliver dysfunction.

You don’t have to obey every demand. But ignoring the electorate entirely?

History suggests that it never ends well.