Professor Paul Clayton explains why fibre diversity, not quantity, is the real key to gut health, longevity, and a smarter microbiome.
fibermaxxing is the health craze taking over your feed and is not without merit: it is grounded in real science. More fiber genuinely does mean a healthier gut, a stronger immune system and a significantly lower risk of serious disease.
But Professor Clayton has a word of caution for anyone about to dramatically ramp up their fiber intake overnight: "fibermaxxing is not for the weak," he says. "I'm not even sure it's for the strong either."
Professor Clayton is one of the world's leading authorities on longevity nutrition. He has spent five decades researching the longest-living populations and discovered that prebiotic fiber was instrumental in preserving their health as they aged. It is a view that informed every decision behind LYMA ID², his most ambitious and pioneering formulation to date.
What is fibermaxxing?
The idea is simple: pile as much fiber into your daily diet as possible to keep you full for longer, supercharge your gut and slash your risk of colon cancer, cardiovascular disease and diabetes. Expert guidance suggests building fiber into meals throughout the day, topping up with seeds, keeping the skin on potatoes or apples, adding chickpeas or beans to curries and pasta. Small changes, proponents argue, that can help you double or even triple your daily fiber consumption.
The science behind the benefits is unequivocal. In 2015, the Scientific Advisory Committee on Nutrition found that every 7g daily increase in fiber could lower your risk of heart disease and cancer by up to 9%. A 20-year study published in Nutritional Neuroscience found that higher fiber intake is associated with a lower risk of developing dementia. And according to the US National Institutes of Health, increasing daily fiber intake by just 9 grams could save an estimated $12.7 billion in annual healthcare costs related to constipation alone.
Most of us are not eating enough. Just 4% to 9% of UK adults meet the recommended 30g daily target. In the US, an estimated 95% of adults and children fall short. The gap between what we eat and what we should eat is vast and the consequences for public health are significant.
So why is Professor Clayton skeptical?
The problem with megadosing fiber
fibermaxxing is part of a broader megadosing trend in nutrition; the idea that if something is good, more of it must be better. Professor Clayton's concern is not with fiber itself, but with the speed and indiscriminate nature of the approach.
"Even a suboptimal microbiome has a relative stability you can function with," he explains. "fibermaxxing creates such a rapid and massive turnover in gut bacteria that the transition itself becomes the problem."
The symptoms are familiar to anyone who has ever dramatically increased their fiber intake overnight: bloating, distension, pain. But Professor Clayton's concern goes further than temporary discomfort. A sudden, dramatic shift in gut bacteria can exacerbate certain conditions - disrupting an equilibrium that, however imperfect, the body has learned to work with.
The gut is not a single chamber. It has four distinct sections, and each requires different fiber types of varying lengths and molecular complexity to nourish the bacterial populations within it. Short-chain fibers, such as inulin and FOS, ferment rapidly in the upper colon. They fuel a quick burst of bacterial activity but are exhausted before reaching the distal colon, the section research suggests may be most critical for long-term disease prevention. Indiscriminate fibermaxxing, however well-meaning, fails to address this. Adding chia seeds to a smoothie and chickpeas to a curry increases quantity. It does not guarantee full-colon coverage.
This is why LYMA is so pioneering. Rather than flooding the gut with a single fiber type, its four-fiber formulation - IMOfibe®, PromOat® oat beta-glucan, chicory inulin and fructo-oligosaccharides - works to deliver 8.5g of short, medium and long-chain prebiotic fibers in a single daily serving, each targeting a different section of the colon. The result is a gradual, progressive transformation of the entire microbiota, not a shock to the system, but a recalibration of it. It is the only gut powder available to do so.
Why prebiotic fiber diversity is the real story
The dietary target that research increasingly supports, and that Professor Clayton has long championed, is 15 grams of diverse prebiotic fiber daily. Not total fiber. Prebiotic fiber specifically - the kind that actively feeds beneficial gut bacteria rather than simply passing through.
"The modern gut crisis is fundamentally a fiber crisis," says Professor Clayton. "We have stripped from our diets the very substrate that gut bacteria evolved to eat over hundreds of thousands of years. But the solution is not simply to eat more fiber. It is to eat the right kinds and also to understand why that distinction is important."
Variety matters as much as quantity. Different fiber types feed different bacterial strains. A single fiber type, however well-intentioned, cannot cover the entire colon. The rational approach, Professor Clayton argues, is to gradually increase intake across a portfolio of different fibers, specifically chosen to provide coverage across all major sections of the colon. This transforms the whole microbiota progressively rather than shocking it.
This is not fibermaxxing. This is fiber intelligence.
The science of full-colon coverage
Long-chain fibers are more structurally resistant than their short-chain counterparts. They travel further before fermenting, reaching the lower colon where bacterial populations are densest and fermentation products have the greatest impact on systemic health. A strategy that combines short, medium and long-chain prebiotic fibers produces a more complete, whole-colon effect - not just more fiber, but smarter fiber precisely matched to the full length of the gut.
