Fermented dairy foods like yogurt have long been linked to digestive, immune, and metabolic health. As interest in plant-based eating has risen, so has the popularity of yogurt alternatives made from soy, almond, oat, and more. Marketed as healthy alternatives to dairy, these products quickly gained consumer trust—but do they actually deliver the same benefits?
To answer that, researchers launched a groundbreaking study comparing dairy yogurts and plant-based-alternative yogurts under controlled digestive conditions. Using a state-of-the-art human gastric simulator, the team investigated how each product performed in the stomach and small intestine—from pH and protein breakdown to probiotic survival.
Although both dairy yogurt and plant-based alternatives are made using the same beneficial starter cultures (e.g., Streptococcus thermophilus and Lactobacillus delbrueckii spp. bulgaricus), their food matrices differ greatly in nutritional content, bioactive properties, and physical structure. This project aimed to fill the knowledge gap by studying how fermented dairy and plant-based foods behaved during digestion and identifying the mechanisms behind any differences.
The project addressed two main objectives: (1) compare the buffering capacity, pH, gastric emptying, and protein hydrolysis of commercially available dairy yogurts and plant-based alternatives during simulated gastric and intestinal digestion; and (2) quantify the viability and intestinal localization of probiotic bacteria from these products under the same conditions. A dynamic gastric model—the human gastric simulator—was used to replicate stomach peristalsis, temperature, gastric secretions,
and emptying.
By studying the effects of digestion on yogurt structure and function, the research aimed to identify the compounds and food matrix interactions responsible for health-related outcomes along the gastrointestinal tract, including effects on the intestinal lining and gut microbiome. This approach provided deeper insights into how yogurt may support intestinal, immune, and metabolic health, while also helping to differentiate dairy yogurts from plant-based alternatives.
The research focused on how stomach and small intestine conditions affect the physical and chemical properties of yogurt and alternative products, and how well different types of food matrices can carry live probiotic bacteria through the digestive tract.
What Did They Find?
Among all products, low-fat Greek-style yogurt had the highest acidity and protein content. In contrast, coconut-based alternatives had the lowest protein content—5 to 20 times lower than the other yogurts and yogurt alternatives. Among the plant-based varieties, soy and protein-fortified almond alternatives had protein levels similar to low-fat and whole-fat milk Greek-style yogurts.
Dairy yogurts had a lower pH and approximately three times higher total acidity than plant-based alternative yogurts. They also contained about twice the protein and had a 1.4 times greater total buffering capacity on average.
Overall, dairy yogurts had significantly higher total and viable bacterial cells numbers than plant-based yogurts.
Why Does It Matter?
This study shows that the fat and protein composition of the yogurt impact factors like pH and buffering capacity which impact the viability of bacterial cells. In essence, dairy and plant-based fermented foods both offer unique food matrices in which specific bacteria can be housed and delivered to the human intestine during digestion.