Lactobacillus rhamnosusGG attenuates tenofovir disoproxil fumarate-induced bone loss in male miceviagut-microbiota-dependent anti-inflammation

Abstract

Background: Although antiretroviral agents trigger bone loss in human immunodeficiency virus patients, tenofovir disoproxil fumarate (TDF) induces more severe bone damage, such as osteoporosis. While, the mechanisms are unclear, probiotic supplements may be effective against osteoporosis. Methods: C57BL6/J mice were administered with Lactobacillus rhamnosus GG (LGG)+TDF, TDF, and zoledronic acid+TDF, respectively. Bone morphometry and biomechanics were evaluated using microcomputed tomography, bone slicing, and flexural tests. The lymphocyte, proinflammatory cytokines, and intestinal permeability levels were detected using enzyme-linked immunosorbent assays, quantitative real-time polymerase chain reaction, and flow cytometry. The gut microbiota composition and metabolomics were analyzed using 16S recombinant deoxyribonucleic acid pyrosequencing and ultra-performance liquid-chromatography–quadrupole time-of-flight mass spectrometry. Results: LGG administered orally induced marked increases in trabecular bone microarchitecture, cortical bone volume, and biomechanical properties in the LGG+TDF group compared with that in the TDF-only group. Moreover, LGG treatment increased intestinal barrier integrity, expanded regulatory T cells, decreased Th17 cells, and downregulated osteoclastogenesis-related cytokines in the bone marrow, spleen, and gut. Furthermore, LGG reconstructed the gut microbiota and changed the metabolite composition, especially lysophosphatidylcholine levels. However, the amount of N-acetyl-leukotriene E4 was the highest in the TDF-only group. Conclusion: LGG reconstructed the community structure of the gut microbiota, promoted the expression of lysophosphatidylcholines, and improved intestinal integrity to suppress the TDF-induced inflammatory response, which resulted in attenuation of TDF-induced bone loss in mice. LGG probiotics may be a safe and effective strategy to prevent and treat TDF-induced osteoporosis.

The role of gut microbiota in bone homeostasis

“…Ovariectomy was performed on mice in three studies, 44 , 49 , 50 and rats in five studies. 55 - 58 , 62 Other methods included high-fat diet (HFD), 60 tenofovir disoproxil fumarate (TDF), 40 and glucocorticoid (GC) in two studies. 46 , 53 One study performed sex steroid depletion by leuprolide.…”

“…The most common intervention was probiotics including Lactobacillus rhamnosus GG (LGG), 34 , 39 , 40 , 46 Lactobacillus reuteri (LR), 42 , 46 , 49 , 63 Lactobacillus paracasei , 44 , 60 Lactobacillus plantarum , 44 and Lactobacillus bulgaricus and Lactococcus lactis . 51 Prebiotics included xylooligosaccharide, 60 fructooligosaccharide (FOS), glucomannan, 52 and acid-hydrolyzed high amylose corn starch (AH-HAS).…”

“…Gut microbiota was determined in 24 studies, and 19 studies performed 16S ribosomal RNA (rRNA) sequencing. 35 , 38 - 40 , 42 , 43 , 45 , 46 , 49 - 51 , 53 , 54 , 56 - 59 , 61 , 63 One study performed metagenomic analysis. 41 Two studies used culture-dependent analysis, 52 , 55 and six studies performed quantitative polymerase chain reaction (qPCR) analysis to quantify bacteria load.…”

“…For bone assessment, a total of 25 studies performed micro-CT to measure BMD and microstructural parameters. 33 - 40 , 42 , 44 - 51 , 53 - 58 , 61 , 63 Two studies performed peripheral quantitative CT (pQCT). 33 , 44 Six performed dual-energy X-ray absorptiometry (DXA).…”

“… 54 In total, 14 studies performed static and dynamic bone histomorphometry analysis. 33 , 34 , 38 - 40 , 46 - 49 , 55 , 56 , 60 , 61 , 63 Eight studies performed mechanical testing. 35 , 37 , 42 , 46 , 54 , 55 , 57 , 63 Nine studies had bone histology including haematoxylin and eosin (H&E), tartrate-resistant acid phosphatase (TRAP), and toluidine blue and safranin O/fast staining.…”