Advances in the study of the role of Lactobacillus lactobacillus in childhood dental caries.

Childhood rickets are one of the most common oral diseases in children, and with the progression of rickets, rickets gradually lead to stunted growth and development in children, including dysponal disorders, malnutrition, constant teeth and abnormal growth and development of the jaws.
economic and social development, children's diet structure and living habits are also changing dramatically, which to some extent affects the prevalence of childhood rickets.
in children's mouths include acid-producing bacteria such as Streptococcus mutants (S. mutans) and Lactobacillus (LB), which can cause tooth de-mining and disintegyation.
more and more domestic and foreign studies show that LB is closely related to the progression of rickets, and this paper summarizes these studies to provide a basis for future oral health education and disease prevention and treatment.
, the second national oral epidemiology survey in 1995 showed that the incidence rate of rickets among children aged 5 years in China was 76.55 per cent and 45.8 per cent among children aged 12.
The results of the third national oral health epidemiological survey in 2005 showed that the rate of lactation in 5-year-old children was 66%, the rate was 3.5, the rate of rickets in 12-year-old children was 28.9%, and the rate of moles was 0.5, a downward trend compared with 1995.
results of the third survey in 2005 showed that the incidence rate of 5-year-old children in Guangdong was 68.2%, which was 4.19, and that of 12-year-old children was 32.9%, which was 0.61, higher than the national average.
1992-1994, 12-year-old children in the United States were 1.4 years old, and children aged 5 to 7 years were 1.7 years old.
1986-1987, the National Dental Research Institute (NIDR) conducted a survey of the prevalence of dental caries in school-age children in the United States, and found that children's molars were 3.07, with 1.97, compared with 1 There was a significant decrease of 4.77 and 2.91 in 979-1980, and 3.91 in children aged 5-9 years, down from 5.32 in 1979-1980.
different regions and countries, the World Health Organization (WHO) published in 1991-2001 12-year-old children are 2.1 in Canada, 1.2 in Denmark, 2.4 in Japan, 0.89 in the United Kingdom, 0.8 in Australia, 2.9 in Afghanistan and 4.1 in Central Africa.
from the current global average of 12-year-old children, the top countries are mostly developing countries, which may be related to economic level, diet, water fluorine content and so on.
, the diversity of Lactobacillus lactobacillus in the mouth reported that LB includes more than 100 genotypes, and its gene sequence also shows different genome sizes, GC content, different expressions of specific gene locations, etc.
LB is a terrain-positive and anaerobic or anaerobic bacteria with multiple gene sizes of 1.23 to 4.91Mb and GC content of 31.93% to 57.02%, widely found in the oral and gastrointestinal tracts of food, water, soil, humans and other animals.
in the LB genotype there are more than 100 kinds, there are 11 common, and in children's mouth, LB mainly includes the following 8 kinds: fermented lactobacillus fermentum, lactobacillus casei, lactose lactobacillus rhamnos us), Lactobacillus gasseri, Lactobacillus salivarius, Lactobacillus plantarum, Lactobacillus vaginalis, Lactobacillus vaginalis, Lactobacillus.
3. The carcinogenic effect of Lactobacillus lactobacillus and the antibacterial effect 1. Lactobacillus 1. In the history of the study of rickets, human beings have been studying the relationship between LB and rickets for more than 100 years.
fact, LB was considered the leading pathogen of rickets until S. mutans became the main pathogenic bacteria.
currently, there are no tracking reports of a correlation between early lactobacillus implantation and infant caries (ECC), but there are significant differences in detection of lactobacillus in the mouths of children without bacillus and ECC.
Yang and others detected 10 types of Lactobacillus in the mouths of 10 severe infants and young children (severe childhood caries, SECC), of which rats had the highest proportion of Lactobacillus lactobacillus (80%), followed by fermented Lactobacillus (60%) and Lactobacillus (60%), and 90% of SECC children had 3 or more LBs in their mouths.
, Teanpaisan and Titasomakul, among others, detected and damaged S. mutans and LBs in oral saliva at 3, 9, 12, 18, 24 months in 169 children in a certain area of Thailand, and found that in 24-month-old children, The detection rates of S. mutans and LBs were 86.98 percent and 66.86 percent, respectively, and the detection rate of LB was significantly higher among children under 1 year of age (3, 9, 12 months) than that of S. mutans, suggesting that LB had a relationship with early damage.
24 months of age had a higher risk of rickets as the number of LBs in the mouth increased, with a 3.1% risk of LB count 1 to 50CFU/1.5 cm2 in saliva and 13.3% in 50CFU/1.5 cm2.
the admonising of LBs can be detected in the mouths and holes of children under the age of 6, and the number of LBs increases as rickets progress, while LB is rarely detected in the mouths of children without rickets.
development of rickets begins with the attachment of plaques, a large number of bacteria attached to the surface of the teeth, the use of sugar metabolism to produce acid, reduce the pH of the oral environment, resulting in the de-mining of the surface of the teeth.
S. mutans are planted on the surface of the teeth, providing favorable conditions for the less adhesive LB.
as early as 1983, Burt and others proposed that S. mutans were a necessary but not sufficient condition for the grooves.
1994 Fitzgerald and others have been found to have synergies between S. mutans and LBs in secondary development.
2016 Neves and others studied changes in bacterial groups in dental intrinsic moth activity and found that the proportion of Bifidobacteria genus and cheesecella in the active tissue of rickets was significantly higher than that of incasion tissue.
and other studies have found that Lactobacillus, Bifidobacteria and Neisseria are more common in children without rickets than in children with the disease.
A three-year follow-up study of 276 school den closures by Muller-Bolla and others found that closing the grooves of the first constant teeth effectively reduced the number of LB and S. mutans in oral plaques, thereby reducing the incidence of rickets in children. Lactobacillus lactic acid in
plaques, in collaboration with S. mutans, uses polysaccharides to secrete organic acids, mainly lactic acid, acetic acid, propic acid, so that local pH is significantly reduced, when pH drops below the critical value (generally 5.5), acids through the diffusion channels of water, protein and fat between glazed crystals diffused into the enamel, phosphate and hydroxyorides are replaced by hydrogen ions, calcium and phosphate and other minerals lost, crystals.
When the oral cavity is in an acidic environment for a long time, S. mutans and LBs exist and produce a large amount of acid, local pH long-term below the critical value, enamel de-mining is greater than re-mineralization, resulting in complete de-mining, crystal structure widely collapsed, forming a cavity.
2. Antibacterial effects of Lactobacillus lactobacillus: According to the official definition of probiotics by the International Association of Science: bacteria that survive in sufficient numbers and are beneficial to the host in the host body, most commonly LB and Bifidobacteria in the mouth.
LB is a common probiotic, widely found in the human gastrointestinal tract, genitourinary system, in the regulation of local microbial ecological balance has an important role.
Caglar and Hattakka studies have shown that some LBs such as Roy's Lactobacillus, probiotics or H2O2 produced by Lactobacillus lactose in rats, antifungal polypeptides inhibit the growth of other oral pathogens such as S. mutans, and Candide.
such as Ahola and Chuang, have shown that certain lactobacillus bacteria in the mouth can lower the level of S. mutans in the mouth.
2015 Sidhu and other studies found that long-term intake of a certain amount of probiotics in children can significantly reduce the level of S.mutans in the mouth.
Probiotics such as Bifidobacteria, Lactobacillus saccharides in mice, and probiotics produced by Lactobacillus Roe can inhibit the growth of pathogenic bacteria in the mouth, thereby inhibiting the development of rickets, periodontology, oral mucosal disease, but early studies have not clarified its specific mechanism.
, there are many options for identifying LB by the research method of identifying the type of Lactobacillus lactobacillus in the mouth, and the earlier method is to identify the type of LB by using selective culture base separation.
addition, LB species can be identified at the gene level, while molecular biology methods for identifying LB-specific strains or specific genotypes include random primer polymerase chain reaction (arbitrarily primed polymerase chain reaction, AP-PCR), denaturing gradient gel electrophoresis (DGGE), 16 SrRNA gene sequence analysis, using PCR binding to limit enzyme-cutting fragment polymorphism analysis (chromosomal DNA finger printing, CDF), nuclear glycosome genotyping, pulse field gel electrophoresis and repetitive enzyme-cutting fragment analysis, among which PCR-based DNA fingerprinting technology can detect the overall genotype of LB at the gene level, and even highly specific identification of strains.
second-generation sequencing technology (The next gene ration sequencing technology, NGS), which has been widely used in recent years, has also greatly contributed to the development of microbial research and analysis.
AP-PCR is a technique for amplification of gene sequence templates for unknown purposes by randomly designing or selecting a nonse specific quotation.
, according to Walter and others, LB's AP-PCR lead screens 16SrRNA gene fragments of amplified LB for upstream and downstream citations (Lac2), while a GC size 40bp Hairpin structure (5'-GCCCGGCGCGCGCGCCCGCGCGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
DGGE technology adds a denaturation agent gradient based on a general polyacrylamide gel, allowing dna fragments of the same length but with different sequences to be distinguished.
specific DNA fragments have their own sequence composition, whose sequence composition determines their unchained region and the behavior of the unchained chain.
NGS includes technology platforms such as 454FLX, Illumina and Apple Biosystems SOLID system.
In 2016, Rôas et al. analyzed 10 samples of the essentially bad tooth of irregenic myelitis by sequencing 16SrRNA genes, and found that at the genus level, LB genus accounted for about 42.3% of the flora and S. mutans accounted for about 5.5%, which also suggested that LB genus was closely related to the occurrence of irregenic myelitis.
5, the mother and children's disease relationship research status quo early disease-cause bacteria sources in addition to food, gastrointestinal tract and other infectious population transmission.
that there is evidence of horizontal transmission among children in some kindergartens in China or Brazil.
In 2012, Teanpaisan and others studied the genotype distribution of 181 pairs of mother-child oral S. mutans and LBs in Thailand and found significant correlations between oral S. mutans and LB levels in children, while the genotypes of mother-to-child oral S. mutans and LB were 76% and 50%, respectively, suggesting a vertical transmission relationship between mothers and children.
Caufield and others studied 15 pairs of mother-child oral LB genotypes and found that only 23 percent of the group had the same genotype, suggesting that the LB genotype was the same not only due to vertical transmission between mothers and children, but also through similar food intake.
, the conclusion of China's 5 to 12 years old children or high incidence of rickets, the oral carbigus groups include S.mutans, LB and lineage genus.
LB, as a long-term and large number of bacteria in the mouth, can co-exist with streptococcus, but also by secreting antibacterial substances to inhibit the growth of other bacteria.
the study of LB has gradually entered the gene molecular level, using AP-PCR, CDF and DGGE technology to analyze the genotypes of LB in the mouth by analyzing the specificity of 16SrRNA gene fragments of LB.
, looking forward to LB plays an important role in the development of children's dental caries, and the occurrence of rickets and children's eating habits, oral hygiene has a great relationship.
Although individual studies have found a correlation between 3 and 6 years of age and the LB genotype in their mother's mouth, these studies are not widespread and only describe their relevance, and domestic studies are rare.
refore, this paper believes that the next step should be to study the type of LB in the mouths of children with rickets and their mothers at the genetic level, on the other hand, it can further prove the vertical transmission relationship between mothers and children with rickets.
Source: Chinese Journal of Oral Medicine Research (Electronic Edition) December 10, 2016 Volume 10, No. 6 Huang Weiman, Gu Haijing, Sun Yat-sen University Guanghua School of Stomology, Affiliated Oral Hospital Source: Huang Weiman, Gu Haijing.