Human Intervention Trials
A central objective of HealthFerm is to generate scientific evidence on the health effects of fermented plant-based foods and to better understand the biological mechanisms that may underlie these effects. To achieve this, HealthFerm has conducted a series of human intervention studies ranging from highly mechanistic experiments to longer-term dietary interventions in people at increased risk of cardiometabolic disease. Together, these studies investigate how fermented foods influence the gut microbiome, metabolism and human health, and whether fermentation can enhance the nutritional and functional properties of plant-based foods.
Portfolio Diet Study
The HealthFerm portfolio diet study evaluated the impact of a plant-based diet rich in fermented foods compared with a matched non-fermented diet and with participants' habitual dietary pattern. The study focused on individuals at increased risk of cardiometabolic disease and combines metabolic phenotyping with microbiome and metabolome analyses. The goal was to determine whether fermentation can enhance the health benefits of plant-based dietary patterns and to identify potential mechanisms linking fermented foods, the gut microbiome and metabolic health.
Fermented Dairy Alternative Study
This intervention evaluated the effects of a fermented oat-based dairy alternative enriched with both dietary fibre and plant protein in adults with mild metabolic deterioration. Consumption of the fermented oat product resulted in modest reductions in LDL- and non-HDL-cholesterol concentrations, while other cardiometabolic parameters showed only limited changes. Importantly, these effects were not substantially different from those observed after consumption of a non-fermented oat-based comparator produced from the same ingredients. Detailed physicochemical analyses demonstrated marked effects of fermentation and enzymatic processing on β-glucan molecular weight, starch composition and product structure, but the authors concluded that the observed cholesterol-lowering effects were more likely related to the increased intake of oat fibre than to fermentation itself. These findings highlight the importance of distinguishing the effects of fermentation from those of the food matrix and fibre content when evaluating health benefits of fermented plant foods.
Fermented Meat Alternative Study
A second product-focused intervention evaluated a fermented plant-based meat alternative. The study explored whether fermentation can improve the nutritional quality of plant proteins and influence cardiovascular risk factors. Particular attention was given to how fermentation may modify the availability of nutrients in the small intestine and the metabolic activity of the gut microbiota in the colon.
Short-Chain Fatty Acid Studies
Short-chain fatty acids (SCFAs) are key metabolites produced when gut microbes ferment dietary fibre and are thought to contribute to many of the physiological effects associated with fibre-rich diets. HealthFerm therefore included mechanistic human studies investigating the effects of targeted SCFA delivery to different regions of the gastrointestinal tract. In a randomized crossover trial in healthy adults, delivery of SCFAs to the small intestine resulted in substantially higher circulating concentrations of acetate, propionate and butyrate than delivery of the same dose to the colon. In contrast, colonic delivery elicited a stronger PYY response, whereas small intestinal delivery unexpectedly produced the largest GLP-1 response. Both delivery routes reduced subjective appetite, although no effects on glucose or c-peptide concentrations were observed. These findings demonstrate that the physiological effects of SCFAs depend not only on the amount produced but also on the location within the gastrointestinal tract where exposure occurs. The study provides direct evidence that the site of SCFA delivery influences systemic availability and endocrine responses in humans.
From Mechanisms to Sustainable Healthy Diets
The intervention studies were complemented by microbiome analyses, metabolomics, in vitro fermentation experiments and population-based research. Together, these approaches provide a unique opportunity to understand how fermentation can be used to develop plant-based foods that are not only sustainable but also designed to support human health. Importantly, the emerging findings from HealthFerm suggest that both food composition and fermentation-derived metabolites contribute to physiological responses, while also illustrating that fermentation does not automatically confer additional health benefits beyond those associated with the underlying fibre-rich plant food matrix.
As scientific results become available through peer-reviewed publications, this section will be updated with key findings from the individual studies.