Effect of probiotics of the genus Bifidobacterium on the modulation of immune response and leveos of alveolar bone loss promoted by experimental periodontitis in mice

Author(s)

Natali Shimabukuro

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia (FO/SDO)
• Defense date: 2019-11-29

Examining board members

Marcia Pinto Alves Mayer; Marinella Holzhausen Caldeira; Anna Carolina Ratto Tempestini Horliana; Adriana Bona Matos

• Advisor: Marcia Pinto Alves Mayer

Abstract

Periodontal disease is an inflammatory disease in response to the dysbiotic microbiota, which leads to the destruction of tooth support tissues. Previous in vitro studies have shown the potential of Bifidobacterium probiotics to affect P. gingivalis oral colonization and to modulate the response to periodontal pathogen. The present study aimed to determinate the ability of two probiotic strains of the genus Bifidobacterium to control the destruction of periodontal tissues and to modulate the immune response in an in vivo assay. B. breve 1101A and B. bifidum 1622A were tested in an animal model of experimental periodontitis induced by oral infection with a microbial consortium (Porphyromonas gingivalis W83, capsulated / afimbriated and ATCC 33277, uncapsulated / fimbriated, Prevotella intermedia 17, Fusobacterium nucleatum ATCC 25586 and Streptococcus gordonii DL1) in C57 / BL6 mice. For induction of periodontitis (P +), the animals were inoculated orally with 1X1011UFC of each bacterial strain 25 times for 5 weeks. Probiotics (B + 1101 or B + 1622) (1X109UFC) were administered orally daily throughout the experimental period. Control groups (P- and B-) were evaluated. After 45 days, euthanasia and samples collection were performed. Alveolar bone loss was determined by microCT, P. gingivalis levels by qPCR, expression of genes associated with RT-qPCR inflammation, serum cytokine profile by ELISA, and T-cell phenotype by flow cytometry. There were no differences in weight gain throughout the experiment among groups (ANOVA, Tukey\'s Multiple Comparison, p <0.05), except for the group P+B+1101. The groups that received only the probiotics [groups P-B + (1101) and PB + (1622)] presented alveolar bone volume similar to the control (SHAM). The protocol employed allowed the induction of experimental periodontitis, evidenced by alveolar bone loss in the P + B- group. The group P+B+ (1101) presented alveolar bone volume similar to P + B-, whereas P+B+ (1622) presented bone volume similar to the control (SHAM). On the other hand, P. gingivalis was not detected in any oral biofilm, feces and spleen samples of the studied groups. However, P. gingivalis was detected in liver samples of the P + B + group (1101), suggesting that B. breve 1101A favored the colonization of P. gingivalis. Inoculation of the microbial consortium (P + B-) and/or B. bifidum 1622A [P-B + (1622) and P + B + (1622)] was not able to induce the expression of il-1? and tnf-? in gingival tissue. However, the transcription of il-1? and tnf-? was up-regulated in the gingival tissue of the groups that received B. breve 1101A, which was attenuated by the microbial consortium [group P + B + (1101)]. The microbial consortium (group P + B-) was not able to positively regulate the expression of tlr2, tlr4, and nlrp3. However, the positive regulation of transcription of these genes was observed in the P-B + (1101) group, which was attenuated by the microbial consortium [group P + B + (1101)]. Upregulation of tlr4 was also demonstrated in samples from the group P + B + (1622). Analysis of the T cell phenotype in gingival tissue samples revealed that the microbial consortium (group P + B-) did not alter the proportion of Treg or Th17 in relation to SHAM. On the other hand, there was an increase in the percentage of Th17 in P-B + (1101) and P + B + (1101) groups, compared to SHAM and P + B- groups. There was no difference in the percentage of Treg and TH17 phenotypes in spleen samples from the P + B- and SHAM groups. However, samples from the probiotic groups [P-B + (1101), P + B + (1101), P-B + (1622) and P + B + (1622)] showed a reduction in the Treg population and an increase in Th17 compared to the P + B- group and/or SHAM. There were no differences in the Treg and Th17 lymph nodes populations among the studied groups. The microbial consortium did not induce alterations in serum levels of IL-10 and TNF-? [P+B- similar to SHAM]. However, IL-10 serum levels were lower in P+B+ (1101), P-B + (1622) and P+B+ (1622) groups than in SHAM. The data suggested that both tested probiotics alter the immune response in C57B / 6 mice induced by human periodontal pathogens or the resident microbiota. However, the regulation in response is distinct between the strains, and B. bifidum 1622A, but not B. breve 1101A, has the potential to attenuate the alveolar bone loss induced by periodontopathogens. (AU)

• FAPESP's process: 17/22345-0 - Effect of Bifidobacterium probiotics on the modulation of immune response and alveolar bone loss in an experimental periodontitis model on normoglycemic and diabetic mice
• Grantee: Natali Shimabukuro
• Support Opportunities: Scholarships in Brazil - Master