Although fiber remains a highly evidence-backed tool for improving long-term health, Dr. Rajan said that fiber is underappreciated due to its simplicity.
“People gravitate toward things that feel futuristic,” Dr. Rajan said. “But when you look at the epidemiology, fiber is one of the most consistently associated dietary factors reducing mortality and disease risk.”
He pointed to large-scale cohort studies and meta-analyses showing that higher fiber intake is linked to reduced risk of cardiovascular disease, type 2 diabetes and all-cause mortality. Despite this, fiber remains overshadowed by trendier ingredients like NAD and peptides.
A key piece to fiber’s role in healthspan is its interaction with the gut microbiome. Unlike other nutrients, fiber reaches the colon largely undigested, where it is fermented by microbes into short-chain fatty acids such as butyrate. These compounds support gut barrier integrity, regulate immune responses and influence metabolic health.
“Fiber isn’t just roughage,” Dr. Rajan explained. “It’s a substrate that allows your microbiome to produce molecules that regulate human physiology.”
While emerging areas such as the gut-brain axis and psychobiotics are promising, Dr. Rajan said that current evidence remains largely associative rather than causal.
Dr. Rajan also pointed out how fiber has historically been marketed in a very clinical or medicinal way.
“So if we hark back to the bran cereal or laxative era, that’s the connotation that people usually have with fiber,” he said. “So it was relegated to the bathroom cabinet or something like that. And that’s part of what we’re trying to do with LOAM, is make fiber easy to integrate into everyday life rather than something that people think about only when digestion becomes a problem and to your point, make fiber sexy for the first time ever.”
Despite strong scientific backing, most consumers still fall short of recommended fiber intake. Dr. Rajan attributes this to the modern food environment, dominated by ultra-processed, low-fiber options, as well as fiber’s historical positioning as a medicinal ingredient.
Looking ahead, Dr. Rajan expects fiber to play a more prominent role in functional foods and supplements, particularly as innovation improves taste, texture and formulation. He also predicts a shift toward more personalized approaches, with tailored prebiotic fiber blends designed to target specific microbiome profiles.
“Fiber will become a central pillar of next-generation nutrition,” he said, “but we need to move beyond thinking of it as a single ingredient and start understanding its diversity and precision.”
To hear more on fiber, gut health and longevity—and what’s next for LOAM—listen to the NutraCast above or on your preferred podcast platform.
If you enjoy listening to the NutraCast, feel free to leave a review. You can subscribe on Apple, iHeart, Spotify or wherever you get your podcasts.
