Live and heat-killed Lactobacillus reuteri reduce alveolar bone loss on induced periodontitis in rats.

OBJECTIVE: Lactobacillus reuteri is reported as a beneficial adjunct to conventional periodontitis treatment or as monotherapy for gingivitis in several clinical trials. However, probiotics are not free from the risk of adverse effects. We investigated the effects of live and heat-killed (paraprobiotic) L. reuteri during the development of ligature-induced periodontitis in rats. METHODS: Thirty-two male rats were divided into four groups-control group: healthy rats, LIP group: rats with ligature induced periodontitis, LIP/PRO group: rats with periodontitis that received live L. reuteri, LIP/PARA group: rats with periodontitis that received heat-killed L. reuteri. Treatment was administered for 30 days prior to ligation and continued for 14 days until euthanasia. The hemimandibles were removed and submitted to radiographic analysis, microcomputerized microtomography (µCT) and histomorphometric analysis. RESULTS: Radiographic analysis revealed that pro- and paraprobiotics enhanced the percentage of mesial bone support. The µCT analysis showed that paraprobiotic treatment increased bone volume and trabecular number while decreasing total bone porosity and trabecular separation. Live probiotic led to higher trabecular thickness. In the histomorphometric analysis, paraprobiotics significantly prevented furcation bone loss and collagen breakdown, although both pro- and paraprobiotics similarly reduced mesial bone loss. There were no significant differences in attachment loss or the number of tartrate-resistant acid phosphatase -positive cells across treatments. CONCLUSIONS: Although viable and heat-killed bacteria reduced mesial alveolar bone loss and ameliorated furcation microarchitecture parameters, paraprobiotics presented the most pronounced results preventing periodontitis development. This can contribute to the future use of paraprobiotics in the prevention and treatment of periodontitis.

Efeitos do Lactobacillus reuteri viável e inativado pelo calor em periodontite induzida em ratos: estudo imaginológico / Effects of viable and heat inactivated Lactobacillus reuteri on induced periodontitis in rats: an imaging study

A doença periodontal (DP) é caracterizada pela destruição dos tecidos de proteção e suporte dentário, osso alveolar, ligamento periodontal, cemento e gengiva, e é a principal causa de perda dentária na população adulta, um grande problema socioeconômico e de saúde pública. Com o aumento da resistência antibiótica, existe interesse no uso de outras substâncias para o combate de doenças infecciosas, como os probióticos. O uso de probióticos na prevenção e tratamento de doença periodontal em animais tem apresentado bons resultados. O estudo dos efeitos do Lactobacillus reuteri viável e inativado (paraprobiótico) pode esclarecer mecanismos de ação e possibilitar o uso comercial de outras preparações, dado que os paraprobióticos teriam produção facilitada. O objetivo deste trabalho foi analisar os efeitos de L. reuteri, viável e inativado, em doença periodontal induzida em ratos. Foram utilizados 32 ratos machos, divididos em 4 grupos: (1) Grupo Controle: com saúde periodontal (n=8); (2) Grupo LIP: periodontite induzida (n=8); (3) Grupo LIP/PRO: periodontite induzida e probiótico (n=8); e (4) Grupo LIP/PARAPRO: periodontite induzida e paraprobiótico (n=8). A indução da doença periodontal foi realizada com a inserção de fio de algodão ao redor dos primeiros molares inferiores e foi realizado o tratamento com L. reuteri viável ou inativado pelo calor, via oral, diariamente, 30 dias antes da ligadura e 14 dias após, quando ocorreu a eutanásia. As hemimandíbulas direitas foram removidas e submetidas à análise radiográfica para quantificação do suporte ósseo. Foi realizada microtomografia computadorizada para avaliação da microarquitetura alveolar na região do primeiro molar. O uso de paraprobiótico levou à maior porcentagem de ganho de peso, quando comparado aos outros tratamentos. Nas análises radiográfica e microtomográfica, comprovou-se a eficácia da indução de DP, havendo diferença significante de suporte ósseo, perda óssea, porcentagem de volume ósseo, espessura trabecular, número de trabéculas, separação trabecular e porosidade óssea total entre os grupos com DP e grupo controle. Os tratamentos com probiótico e paraprobiótico preservaram de maneira semelhante o volume ósseo (BV/TB), a porosidade óssea total (Po.Tot) e a perda óssea alveolar na furca, embora apenas paraprobióticos tenham levado a uma diferença significativa em comparação ao grupo LIP. Ambos os tratamentos diminuíram a perda óssea mesial alveolar e aumentaram o suporte ósseo alveolar. Além disso, o paraprobiótico diminuiu a separação trabecular (Tb.Sp) e aumentou o número trabecular (Tb.N) Tanto as bactérias viáveis como inativados pelo calor reduziram a perda óssea alveolar e melhoraram os parâmetros da microarquitetura óssea. Estes resultados contribuem para o desenvolvimento futuro de formulações com L. reuteri não viável, que terão maior prazo de validade(AU)

Periodontal disease (PD) is characterized by the destruction of dental protection and support tissues, alveolar bone, periodontal ligament, cementum and gingiva, and is the major cause of tooth loss in the adult population, a major socioeconomic and public health problem. With the increase of antibiotic resistance, there is interest in the use of other substances to combat infectious diseases, such as probiotics. The use of probiotics in the prevention and treatment of periodontal disease in animals has shown good results. The study of the effects of viable and inactivated Lactobacillus reuteri (paraprobiotic) can clarify mechanisms of action and enable the commercial use of other preparations, since paraprobiotics would have facilitated production. The aim of this study was to evaluate the effects of viable and inactivated L. reuteri on induced periodontal disease in rats. Thirty-two male rats were divided into four groups: (1) Control group: with periodontal health (n = 8); (2) LIP group: induced periodontitis (n = 8); (3) LIP/PRO group: induced periodontitis and probiotic (n = 8); and (4) LIP/PARAPRO group: periodontitis induced and paraprobiotic (n = 8). Induction of periodontal disease was performed with the insertion of cotton thread around the lower first molars and treatment was performed with viable or heatinactivated L. reuteri daily, 30 days prior to ligation and 14 days later, when euthanasia occurred. The right hemimandible were removed and submitted to radiographic analysis for quantification of the bone support. A computerized microtomography was performed to evaluate the alveolar microarchitecture in the first molar region. The use of paraprobiotic led to a higher percentage of weight gain when compared to other treatments. In the radiographic and microtomographic analyzes, the efficacy of the DP induction was verified, with a significant difference in bone support, bone loss, percentage of bone volume, trabecular thickness, trabecular number, trabecular separation and total bone porosity between the PD and group control. Probiotic and paraprobiotic treatments similarly preserved bone volume (BV/TB), total bone porosity (Po.Tot) and alveolar bone loss in the furcation, although only paraprobiotic led to significant difference in comparison to LIP group. Both treatments decreased the mesial alveolar bone loss and increased alveolar bone support. Moreover, the paraprobiotic decreased trabecular separation (Tb.Sp) and increased trabecular number (Tb.N). Both viable and heat-killed bacteria reduced alveolar bone loss and ameliorate the bone microarchitecture parameters. These results contribute to the future development of formulations with non-viable L. reuteri that will have a longer shelf-life(AU)