The Ingredient Category Nobody Could Explain to Me, So I Built a Company Around It
Updated: 2 days ago
Alastair Jessel is the Founder & CEO of The Postbiotic Company Ltd (AYA BIOME™) and Director of Battersea Park Clinic, London. He writes The Postbiotic Dispatch, an evidence-led newsletter on gut health, longevity, and the science behind postbiotic supplementation.
A few years ago, I sat in a meeting with a company director who used the word “postbiotic” three times before I finally stopped him and asked what it meant. He looked slightly embarrassed, then spent twenty minutes trying to explain it to me using words like “metabolite,” “epigenetics,” and “bioactive compound.” I left more confused than when I arrived.

That conversation eventually led me to found The Postbiotic Company. Not because I understood postbiotics perfectly, but because I realised almost nobody did, and an entire category of nutrition science was being sold to consumers without anyone bothering to make it make sense. If you've ever stood in a health food aisle wondering whether you need the “billions of live cultures” jar or the fibre powder or the strange new one with the unfamiliar name, this is for you.
The gut isn't a machine, it's an economy
Most people think of gut health as mechanical. Eat the right things, and the machine runs better. I think that's the wrong model. Your gut is closer to an economy. Trillions of microbial residents, each with their own role, all trading resources, producing outputs, and responding to what you feed the system.
Understanding that shift in framing is, I'd argue, the single most useful thing you can do for your gut health literacy. It's the key to understanding the three terms everyone mixes up.
Probiotics are new residents you bring into the economy. Live bacteria delivered via fermented food or a supplement can offer a benefit once they arrive. The catch is that most of them are visitors, not citizens. They have to survive manufacturing, storage, and an acid bath in your stomach before they can do anything useful, and many don't make it. The ones that do tend to pass through rather than settle down.
Prebiotics are the resources that keep the existing economy running–fibres your body can't digest but your resident bacteria can, which they ferment and use as fuel. No prebiotics, no productive microbial activity, no matter how many probiotics you add.
Postbiotics are the output of that economy, the actual goods produced when bacteria ferment those fibres. Short-chain fatty acids like butyrate, which feed the cells lining your gut wall. Enzymes. Peptides with immune-modulating effects. B vitamins. In the case of fermented botanicals, entirely new compounds that didn't exist in the original plant.
This last category is the one I find genuinely interesting as both a founder and a nerd for evidence. Postbiotics were only formally defined by the International Scientific Association for Probiotics and Prebiotics in 2021, remarkably recent for a concept humans have been unknowingly using for millennia through fermented food.
Why I bet a business on the least glamorous option
Here's the uncomfortable truth about probiotics that the supplement industry doesn't lead with–live bacteria are fragile, unpredictable, and hard to standardise. You genuinely don't know how many of those “47 billion cultures” survive to do anything in your gut. It's a bit like judging a football team entirely by how many players show up to the coach at the stadium, with no guarantee they make it onto the pitch.
Postbiotics sidestep that problem entirely. Because the bacteria have already done their fermenting before the product reaches you, what you're consuming is the finished output, stable, measurable, and not dependent on anything surviving your stomach acid. From a product development standpoint, that's not just easier to formulate, it's easier to be honest about.
That mattered to me. I came into this industry from outside it, and one of the things that struck me early was how much of the messaging around gut health supplements is aspirational rather than evidential. Building a company around postbiotics forced a different discipline, because the category is newer and less hyped, there's less room to hide behind vague claims. You have to actually know what's in the jar and why.
The leadership lesson hiding in a petri dish
I didn't expect a supplement category to teach me much about running a business, but it has. The clearest lesson, the least glamorous input often produces the most reliable output.
Prebiotics don't have a marketing budget. Nobody puts “contains resistant starch” on a billboard. But without that unglamorous fibre, none of the more exciting biology downstream happens at all. I see the same pattern constantly in business: the unsexy infrastructure work, the supply chain, the compliance, the operating discipline, is what actually determines whether the exciting, headline-grabbing product survives contact with reality.
Postbiotics, similarly, only exist because something upstream did its job well first. There's a version of that principle that applies to teams, to companies, to almost anything you're trying to build well rather than just build fast.
Where this leaves you
You don't need a biochemistry degree to make better decisions in the supplement aisle. You need one reframe, stop asking “how many live cultures does this contain?” and start asking “what does this actually produce, and how do I know?”
That question is what took me from a confused meeting with a company director to building my own company. It's also, I'd argue, not a bad question to ask about most things you're building or buying, gut health included.
A longer, more clinical breakdown of the postbiotic science, including the research behind fermented botanicals, is available on my Substack, The Postbiotic Dispatch.
Our fermented turmeric postbiotic is not currently approved by the United States Food and Drug Administration (FDA) or the European Food Safety Authority (EFSA) and is therefore not yet available in the USA or EU, but will be soon. For all our readers in the US, you can follow us on our website, and we will commence our rollout there. Germany will follow next in the European Union (EU).
The information in this article is for educational purposes and does not constitute medical advice. If you have specific health concerns, please consult a qualified healthcare professional.
Read more from Alastair Jessel
Alastair Jessel, Founder, CEO & Director of The Postbiotic Company Ltd
Alastair Jessel is the Founder & CEO of The Postbiotic Company Ltd, the maker of AYA BIOME™, a premium postbiotic supplement range built on clinically-studied fermented ingredients. He is also Director of Battersea Park Clinic, an integrative wellness centre in London offering therapies from hyperbaric oxygen to red light and Energy Enhancement Systems. Alastair writes The Postbiotic Dispatch, a Substack newsletter known for its forensic, evidence-led take on the supplement and wellness industry - one that holds his own products to the same scrutiny as everyone else’s. His work sits at the intersection of product development, regulatory compliance, and public education on the emerging science of postbiotics.










