Lactobacillus Rhamnosus SP 1: the probiotic supplement that promotes dental health

  • probiotic for dental health - Lactobacillus rhamnosus SP 1


The following article is drawn from the feature “Aziende - Ingredienti e Prodotti” [Companies - Ingredients and Products] contained in issue 2017 (1) of the magazine “L’integratore nutrizionale” [Dietary supplement]. For the bibliography and to download the full article, click here.

The probiotic strain Lactobacillus rhamnosus has been used for many years in nutraceutical products, demonstrating various health benefits. Recently, it has been shown that administration of Lactobacillus rhamnosus during infancy can lead to a reduction in the incidence of tooth decay.

Composition and technical specifications

Lactobacillus rhamnosus SP 1 is a probiotic strain owned by Sacco S.r.l., registered under DSM 21690, and identified through DNA sequencing coding for rRNA 16S with PCR testing. Typing of the strain was carried out through pulsed-field gel electrophoresis (PFGE). The GM-free bacterial strain is a gram-positive microaerophile and facultative heterofermentative. It is also free from gluten, soya and milk derivatives. As per EFSA indications, tests have been carried out that excluded the presence of acquired and potentially transmissible traits associated with resistance to antibiotics. The technical characteristics of Lactobacillus rhamnosus SP 1 are summarised in Table 1.

Table 1: technical characteristics of Lactobacillus rhamnosus SP 1

Organoleptic characteristics


Visual profile

Freeze-dried, in powdered form

Microbiological characteristics


Bacillus cereus (ufc/g)


Coagulase positive staphylococci (ufc/g)


Enterobacteriaceae (ufc/g)


Escherichia coli (ufc/g)

Not present/25 g

Listeria monocytogenes (ufc/g)


Salmonella spp.

Not present/25 g

Yeasts and moulds (ufc/g)

Not present/25 g

Storage At temperatures below -17°C in the original sealed containers
Stability 18 months


Efficacy and studies

Previous studies in Nordic countries have demonstrated an antagonistic action of Lactobacillus rhamnosus against cariogenic bacteria with consequent reduction in tooth decay in preschool children and a reduction in the risk of tooth decay (1–4).

A group of the Department of Dentistry at the University of Chile in Santiago went on to study the use of Lactobacillus rhamnosus SP 1 (produced by Sacco S.r.l.) and its effects on improvement in dental health in a group of children of preschool age (between two and three years) resident in Chile. No test of this type has previously been conducted in South America. The study carried out (5) involved 205 children attending 16 nursery schools included in the National Nutritional Programme of Santiago de Chile, with higher exposure to the risk of tooth decay. 123 children drank milk with Lactobacillus rhamnosus SP 1 and the other 82 children drank milk containing a placebo.

To participate in the study, children had to be healthy and without any intolerance to milk or other food allergies. The different schools that were part of the group that tested Lactobacillus rhamnosus SP 1 as a supplement and those in the control group were randomly selected. Neither the staff of the schools nor the families of the children or doctors were informed of which nursery schools would receive milk enriched with Lactobacillus rhamnosus SP 1 and which would receive the control milk without the probiotic. While attending the nursery schools on week days, children were given semi-skimmed milk produced with dissolved milk powder and therefore suited to the addition of Lactobacillus rhamnosus SP 1. In parallel, the placebo milk was also distributed, consumed in the same manner, as an afternoon snack (150 ml of milk). The milk was enriched with 1.5 billion live cultures using a freeze-dried culture of Lactobacillus rhamnosus SP1 in powdered form. The test period lasted 10 months and each day of school attendance a diary was filled out by the personnel of the 16 schools regarding the presence of children to guarantee adhesion to the study protocol.

The experimental design was that of a randomised, triple-blind, placebo-controlled parallel study. International ICDAS criteria were adopted for visual and tactile detection of tooth-decay lesions and to describe the severity of these lesions. Children were analysed at the start and end of the study by two dentists instructed by internal and external examiners in order to guarantee consistent and comparable results of the assessments.

Observations showed a slightly lower, yet in any case significant, presence of tooth decay in the group that had received Lb. rhamnosus SP 1 (54.4%) compared to the control group (65.8%). Another finding was that after two weeks without further administration of Lb. rhamnosus SP 1 (in total 12 months after the start of the test) tooth-decay lesions in children that had drunk milk with the addition of Lb. rhamnosus SP 1 were significantly lower (9.7%) compared to the control group (24.3%), demonstrating that the probability of dental lesions deriving from tooth decay during the period after administration of the bacteria was significantly reduced.

The mechanism of action may be linked to the fact that Lb. rhamnosus SP 1 interacts with the oral biofilm, changing its composition in favour of bacteria that produce fewer organic acids, enabling greater balance between the pH of saliva and that of plaque. In addition, this study highlighted a positive impact also after two months without further administration of probiotics. Other studies carried out with probiotic lactic acid bacteria have demonstrated that they were only temporarily present in the saliva, and therefore, a daily intake can be recommended to limit the appearance of tooth decay in children of preschool age. 


Lactobacillus rhamnosus SP 1 is a safe microorganism with QPS (Qualified Presumption of Safety) classification from the EFSA.

Application and methods of use

Lactobacillus rhamnosus SP 1 can be used as a probiotic supplement or added to probiotic food products. In accordance with Ministry of Health guidelines, the recommended total daily consumption of probiotics is 109.


Sacco System produces and markets a wide range of probiotics for dental and oral health.

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Lactobacillus Rhamnosus SP 1: the probiotic supplement that promotes dental health - News
Article from the magazine “L’integratore nutrizionale” [Dietary supplement]. Discover L. Rhamnosus SP 1, the Sacco Probiotic for Oral Health!