**10. Probiotics and oral candida infections**

Another role of a probiotic is to restrain the chronic candida infections of the soft tissues in the mouth. Those that are isolated from oral cavity include *C. albicans*, *C. glabrata*, *C. krusei*, *C. parapsilosis*, and *C. tropicalis*. Many in vitro studies have shown that the strains of lactobacilli have inhibitory activity against oral candida, but the true value of probiotics in controlling oral candida is still an open question [10].

### **11. Probiotics and halitosis**

One of the most common problems that people in the world suffer from is halitosis. This phrase is used in 1921 to describe the unpleasant odor of the mouth [23]. This complication has many causes such as bacterial coating of the tongue, systemic disorders, and different types of food [24]. At all levels, all physical and chemical treatments alone have not been able to completely control this pathology. All physical and chemical treatments alone have not been able to fully control this problem. Today, scientists believe that the use of probiotics as supportive therapies will play a role in controlling this problem. But how can these bacteria help?


These two methods are the main methods for reducing odor in the mouth by probiotics [25].

## **12. Mechanism of probiotics in the oral cavity**

The ability to adhere to and colonize surfaces in the oral cavity is an essential requirement for an oral probiotic [9]. There are four main mechanisms for the effect of probiotic bacteria in the mouth. Probiotics compete with pathogens to stick to the mucosa and tooth and prevent the sticking of pathogenic bacteria [26]. Probiotic produce peroxide and bacteriocin as antibacterial agents against oral pathogens, so they remove from oral area [27]. The presence of probiotics can change the oral conditions such as reducing pH that can prevent the growth of bacteria producing tooth decay or change the protein structure of salivary gland [28]. Probiotics can have beneficial effects on dental health by stimulating non-specific immunity and regulating cellular and humoral immune responses [29].

**67**

**Author details**

Razzagh Mahmoudi1

\*, Sara Moosazad<sup>2</sup>

neutralizing effect on acid production by bacteria [30].

\*Address all correspondence to: r.mahmodi@yahoo.com

University of Medical Sciences, Qazvin, Iran

University of Medical Sciences, Qazvin, Iran

provided the original work is properly cited.

1 Medical Microbiology Research Center, Faculty of public Health Qazvin

2 Department of Health and Food Safety, Faculty of public Health Qazvin

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

and Katayoon Aghaei<sup>2</sup>

*Oral Health by Using Probiotic Products DOI: http://dx.doi.org/10.5772/intechopen.86714*

**13. Probiotic strain in oral cavity**

According to the researches and their results, *Lactobacilli* and *Bifidobacterium* could play an important role in the microecological balance in the oral cavity. *B. bifidum*, *B. longum*, and *B. infantis* are the probiotic species of *Bifidobacterium*. *Bifidobacterium* is seen in deep caries in the oral cavity and plays an important role in the development of caries, but it has been shown that its probiotic species can reduce caries in people who do not have active caries. Acidophilus are the probiotic species of *Lactobacillus*. According to the researches, *Lactobacillus* is more associated with decayed dentin. It is at the point of development of the decayed lesion and is at the onset of the process that caries do not have a role. Consumption of products of probiotics does not predict the cause of decay growth. Firstly, the *Lactobacillus* rarely causes cavity formation. Secondly, all *Lactobacillus* species do not induce caries, and thirdly when carriers of dairy *Lactobacillus* are present, they can have a
