Bovine milk vs plant-based drinks and oral biofilm

Dental Tribune International

Tue. 2. June 2026

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BERN, Switzerland: As interest in plant-based milk alternatives continues to grow, more data is needed to understand their oral health implications in comparison with bovine milk. A new study by researchers at the University of Bern investigated the effects of bovine milk and three plant-based alternatives on selected oral microorganisms and multispecies oral biofilms. The authors concluded that the oral health relevance of plant-based drinks depends on their individual composition and cannot be generalised in comparison with bovine milk.

In the study, the researchers tested unsweetened oat, almond and soy drinks against oral commensal bacteria and bacteria associated with caries and periodontitis, including Streptococcus gordonii, Streptococcus mutans and Porphyromonas gingivalis. They also assessed the impact of the drinks on cariogenic and periodontal biofilm models and, in a cell experiment, whether the drinks influenced immune responses relevant to periodontitis.

According to the authors, bovine milk and the plant-based alternatives had different effects depending on the microorganism, biofilm model and measure tested. Bovine milk and the almond and soy drinks slightly promoted the growth of S. gordonii, an early coloniser of oral biofilm. Effects on S. mutans were limited, although when sucrose was added to mimic a cariogenic sugar challenge, the drinks, particularly bovine milk, reduced S. mutans counts.

In the cariogenic biofilm model, the almond drink reduced colony-forming unit counts, whereas bovine milk and the soy drink reduced the amount of biofilm formed and the metabolic activity within the biofilm. In the periodontal biofilm model, bovine milk and the oat drink reduced both colony-forming unit counts and biofilm metabolic activity. The researchers also reported that the almond drink nearly completely blocked one of the mechanisms by which P. gingivalis contributes to periodontitis.

Another notable finding was that the soy drink appeared to have an anti-inflammatory effect in the cell model. The authors described this as a potential immunomodulatory effect. However, they stressed that the findings are based on in vitro models and should be interpreted with caution until confirmed in clinical studies.

Rising popularity of plant-based milk alternatives

The findings are particularly relevant given the increasing popularity of plant-based milks. Patients may choose these products for reasons such as lactose intolerance, vegan diets, ethical concerns or personal preference. However, the study highlights that plant-based drinks cannot be considered a single category from an oral health perspective, because their effects may differ substantially depending on their composition, including sugar and protein content, as well as their buffering capacity and other factors.

The authors noted that unsweetened plant-based milks with low levels of fermentable carbohydrates may generally have low cariogenic potential, whereas sweetened milks, which were not included in the study, may present a higher caries risk. They also pointed out that plant-based alternatives lack certain protective components found in bovine milk, such as casein, which has been associated with inhibition of demineralisation and promotion of enamel remineralisation.

The study, titled “The in-vitro effect of bovine milk, and plant-based alternatives on oral microorganisms and biofilms”, was published online on 24 April 2026 in Scientific Reports.