Adding One Daily Scoop of Plant Diversity May Improve Gut Health

Modern diets tend to be low in fiber and low in variety, and that combination has been linked to the rise of chronic disease. Most people eat the same handful of plant foods on repeat, which limits the diversity of species living in the gut microbiome, a factor increasingly tied to digestive health, metabolism and overall well-being.

The BIOME study, led by researchers from King’s College London and ZOE, was a six-week randomized controlled trial involving 399 adults ages 35 to 65 with below-average fiber intake. The team set out to test whether a concentrated dose of plant diversity could shift gut bacteria composition and ease common digestive complaints.

Testing Diversity Against a Probiotic and a Placebo

Investigators randomly assigned participants to one of three groups: a daily 30-gram whole-food plant blend, known as Daily30, containing more than 30 ingredients rich in polyphenols, fiber and micronutrients; an isoenergetic control of bread croutons; or a probiotic supplement containing 15 billion CFU of Lactobacillus rhamnosus per day. Neither the participants nor the analysts scoring the results knew which group anyone had been assigned to.

Of the 349 participants who completed the study, adherence was excellent, with more than 98% reporting they stuck to their assigned regimen.

A Clear Difference in Microbiome Impact

The plant blend outperformed both comparison groups by a wide margin. It was associated with changes in the relative abundance of 57 bacterial species, compared with just 14 species in the control group and only 4 species in the probiotic group, both highly statistically significant differences.

Interestingly, when investigators examined whether these shifting species were classified as “favorable” or “unfavorable” for gut health, there was no significant difference between groups, indicating that the blend increased the sheer number of species shifting without a demonstrated skew toward beneficial types.

“This research suggests we should focus on plant diversity, and the role that varied fibers play in shaping the microbiome, rather than searching for a single silver bullet,” said lead investigator Sarah Berry, Ph.D., a professor in the Department of Nutritional Sciences at King’s College London and chief scientist at ZOE.

Real-World Symptom Improvements

Beyond the microbiome data, participants taking the plant blend reported measurable improvements in everyday digestive comfort. Compared with the control group, they experienced significant reductions in indigestion, constipation, heartburn and flatulence, along with a boost in self-reported energy. The intervention appeared safe overall, with only six related adverse events and no serious ones reported across the entire study.

What It Means at Mealtime

A crossover substudy added another layer, testing what happens when the plant blend is added directly to a high-carbohydrate meal. Compared with eating the same meal alone, adding the blend reduced hunger and increased fullness and energy over the following three hours, based on standard measures of appetite response. Notably, it had no effect on postmeal blood sugar levels, suggesting the appetite benefits were not simply a byproduct of blunting a glucose spike.

The Takeaway

Taken together, the findings suggest that a concentrated, diverse plant-food blend may be a practical way to shift gut microbiome composition and ease common digestive symptoms in otherwise healthy adults, more effectively than a standard probiotic in this comparison.

“The fact that Daily30 altered 57 distinct bacterial species in just six weeks reshapes how we should approach gut health,” said Berry. “Rather than introducing isolated strains through a pill, these results prove we can achieve a far greater impact on the gut microbiome composition on the gut microbiome composition by nourishing our existing microbes with a diverse array of plants.”