Impact of Bifidobacterium animalis subsp. lactis HN019 probiotic in the prevention of periodontitis associated with immunosuppression

This study evaluated the effects of the probiotic Bifidobacterium animalis subsp. lactis HN019 (HN019) in the development of experimental periodontitis (EP) in rats submitted to chemotherapy (5-fluorouracil [5FU]).Eighty male rats were divided into the following groups: control (C); treated with 5FU (60 mg/kg at day 30 and 40 mg/kg at day 32); treated with probiotic (HN019) (daily, for 44 days, starting at day 0); treatment with 5FU and probiotic (5FU-HN019); only EP (EP) (ligature placed on lower first molars at day 30, maintained for 14 days); EP and treatment with 5FU (EP-5FU); EP and treatment with probiotic (EP-HN019); and EP and treatment with 5FU and probiotic (EP-5FU-HN019). Euthanasia occurred at day 44. Morphometric, histomorphometric, microtomographic, immunohistochemical, immunoenzymatic, and gene expressions analyses were performed. The data obtained were statistically analyzed (p < 0.05).The EP-5FU-HN019 group showed less bone and connective tissue loss when compared with EP-5FU group, while EP-HN019 and EP-5FU-HN019 groups had greater bone volume than EP and EP-5FU groups, respectively (p < 0.05). A decrease in immunostaining for tartrate-resistant acid phosphatase and RANKL, an increase for osteoprotegerin and lower interleukin-1β levels were observed in EP-5FU-HN019 group, when compared with EP-5FU group (p < 0.0001). Probiotic therapy led to an increase in the proportions of B. lactis in the feces (p = 0.0018), but not in the biofilm, and reduced the expression of Fusobacterium nucleatum and Prevotella intermedia in the biofilm (p < 0.0001).B. lactis HN019 reduced the severity of EP in rats submitted to chemotherapy, modulating immunoinflammatory parameters in periodontal tissues and reducing periodontopathogens expression on biofilm in rats submitted to chemotherapy.