Researchers from Zoe and King’s College London conducted a six-week trial to assess the effects of Daily30, a blend designed to be mixed into food or drinks. They compared it with a probiotic supplement containing Lacticaseibacillus rhamnosus GG – a well-studied probiotic strain known for supporting gut health, maintaining the intestinal barrier, and helping balance the gut microbiome – and a bread crouton control, to assess its effects on gut microbiome composition, digestive health, energy levels and hunger.
“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 Dr. Sarah Berry, professor of nutritional sciences at King’s College London and chief scientist at Zoe, who led the study
Research increasingly shows that healthy dietary patterns improve health partly by influencing the gut microbiome. Plant-derived ingredients can provide prebiotics, such as fiber and polyphenols, which selectively nourish beneficial gut bacteria, promoting microbial diversity and supporting the production of metabolites associated with intestinal health. Fermented foods provide probiotics which introduce specific beneficial bacterial strains, which may help modulate the gut microbiota and support digestive and immune function.
Daily30 is formulated with whole-food ingredients like fruits, vegetables, mushrooms, herbs, spices, nuts, seeds, quinoa, and lentils, and is designed to deliver fiber, antioxidants and plant nutrients to support gut health, reduce inflammation, protect cellular health and promote overall wellbeing. By making plant diversity and fiber intake easier to achieve, Daily30 aims to support long-term healthy eating behaviours rather than replace a balanced diet, Berry explained.
“The global supplement industry is worth billions, yet much of it is built on marketing hype rather than robust science,” said Dr. Tim Spector, scientific co-founder of Zoe and professor of epidemiology at King’s College London
“For too long, consumers have been sold synthetic pills and ultra-processed powders as a quick fix. True nutrition comes from the complex structures of real plants.”
The researchers randomly assigned 349 healthy participants aged 35–65 with low fiber intake to receive either the 30+ plant blend, the probiotic capsule, or the control, which they consumed while maintaining their usual diet
They collected baseline and follow-up data through online questionnaires, dietary recalls, blood samples, stool samples and self-reported health measures. They assessed changes in gut microbiome composition using metagenomic analysis of stool samples, and also measured blood metabolites, diet quality, gastrointestinal symptoms, bowel habits, body measurements, sleep, mood, energy and skin health
Results suggested the plant blend produced the greatest changes in the gut microbiome, with 57 bacterial species changing in abundance after six weeks, compared with 14 species in the control group and 4 species in the probiotic group
Within the plant blend group, beneficial bacteria associated with healthier microbiome and diet profiles increased, while less favorable species declined. The plant blend also altered overall microbiome composition more than either comparison group
“The gut microbiome is an ecosystem of trillions of established microbes – standard, single-strain probiotics often fail to colonize these,” Berry told NI. “Instead, consuming a diverse range of plant-based prebiotic fiber, like those found in Daily30, feeds and strengthens the existing bacteria, which is a much more effective way to improve gut health.”
Participants who consumed the 30+ plant blend also reported modest improvements in energy, happiness and several gastrointestinal symptoms, including reduced constipation, indigestion, flatulence and heartburn, compared with the control group. Compared with the probiotic group, the plant blend also reduced constipation and hunger. However, the intervention did not produce clinically meaningful changes in blood metabolite profiles, body weight, waist circumference, sleep quality or most other health outcomes.
Berry said that the wide variety of plant fibers in Daily30 provided a broad nutrient source that supported the growth of different beneficial bacterial species, while the polyphenols acted as bioactive compounds that could interact with the gut microbiome and promote microbial balance, and the intact food matrix protects the nutrients as they pass through the digestive system, allowing them to reach the gut where they can exert their effects.
“It’s the synergy of the whole plants, not just one single ingredient,” she said
In the postprandial sub-study, which involved adding the plant blend to a high-carbohydrate breakfast, the intervention did not reduce post-meal blood glucose. However, it increased feelings of fullness, energy, and meal satisfaction while reducing hunger, desire to eat, and expected food intake, without affecting the amount eaten at the next meal
“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 by nourishing our existing microbes with a diverse array of plants.”
Overall, the researchers concluded that the 30+ plant blend represents a practical way to increase plant diversity and fiber intake, promoting favourable changes in gut microbiome composition. They recommend larger, longer-term studies in more diverse and higher-risk populations to determine whether these microbiome changes translate into meaningful long-term health benefits
