*Adherence of* Candida albicans *on Polymethyl Methacrylate in Probiotics Solution DOI: http://dx.doi.org/10.5772/intechopen.112321*

substances secreted by tissue which have the ability to stimulate microbial growth. Parker first used the term probiotic in relation to its modern usage, defining it as "organisms and substances that contribute to intestinal microbial balance." Later, Fuller amended this definition by emphasizing the important role of probiotics in establishing the balance of intestinal microbial. This reformed definition emphasizes on the requirement of viability for probiotics and introduces the aspect of a beneficial effect on the host. Havenaar et al. expanded the definition further to include mono or mixed cultures of microorganisms applied to animals or humans that improve the properties of the indigenous microflora. Salminen and Schaafsma further broadened the definition of probiotics to include dairy products such as fermented cereals, sauerkraut, and salami that contain viable probiotic microorganisms. This definition showed that probiotics benefit, effect health and nutrition of the host. Salminen and Schaafsma broadened the definition of probiotics even further by no longer limiting the proposed health effects to influences on the indigenous microflora.

According to today's definition, probiotics are called "healthy bacteria" with many health benefits such as preventing intestinal infections, improving immunity, lactose intolerance and intestinal microbial balance, and anti-hypercholesterolemia and antihypertensive effect, and reduces traveler's diarrhea. Recent research has also focused on their use in the treatment of skin and mouth diseases [2].

### **2.2 Probiotics and oral cavity**

Because oral cavity is the first section of the gastrointestinal tract, it is logical to think that some probiotics may affect the oral microbiota. The most commonly used probiotic bacterial strains are the *genera Lactobacillus* and *Bifidobacterium*. Specific *lactobacilli* species are yet to be identified as exclusively in oral microbiota, although some common ones include *L. paracasei, L. plantarum, L. rhamnosus, and L. salivarius. Bifidobacteria* is among the first anaerobic bacteria to colonize in the oral cavity, and possible species isolated from oral samples are *B. bifidum, B. dentium, and B. longum*. Culture-based studies confirm that *bifidobacteria* is among the first anaerobes in the oral cavity. Indeed, both *lactobacilli* and *bifidobacteria* can be found in breast milk, suggesting early exposure of the oral cavity to these bacteria [4].

### **2.3 Potential mechanisms of probiotic effects in the oral cavity**

Probiotics can improve oral health through three main mechanisms: normalization of oral microbiota, modulation of the immune response, and metabolic effects. By inhibiting harmful bacteria and promoting beneficial bacteria, probiotics can help restore balance in the mouth and reduce the risk of gum disease and tooth decay. Probiotics can also modulate the immune response and prevent inflammation, particularly in individuals with compromised immune systems. Lastly, probiotics can have metabolic effects that improve overall oral health by breaking down food particles and preventing the buildup of plaque and tartar. In summary, the potential mechanisms of probiotic action in the oral cavity resemble those in the intestine and can benefit oral health significantly [5].
