Probiotics provide health benefits in various aspects and are believed to modulate the immune system by balancing gut microbiota homeostasis, termed the "microbiota-immune axis". Recent evidence supports that several Lactobacillus strains possess glucose-lowering and anti-inflammatory effects in an animal model of type 1 diabetes (T1D). Although probiotics of Lacticaseibacillus paracasei SD1 (SD1) and Lacticaseibacillus rhamnosus SD11 (SD11) exert human oral health benefits by reducing harmful bacterial populations, their clinical application regarding hypoglycemic-related traits as well as the underlying mechanisms are still lacking. In this report, we used multiple low doses of streptozotocin (STZ)-induced diabetic BALB/c mice to explore the effects of SD1 and SD11 supplementation on the regulation of markers related to T1D. Experimental mice were randomly assigned into five groups, non-STZ + V, STZ + V, STZ + SD1, STZ + SD11, and STZ + SDM (mixture of SD1 and SD11), and physiological data were measured every week. Blood and pancreas samples were collected at 4- and 8-weeks. Our results indicate that supplementation with SD1, SD11, or SDM for 8 weeks significantly improved body weights, glycemic levels, glucose tolerance, insulin levels, and lipid profiles. Probiotic administration also preserved islet integrity and increased β-cell mass in STZ-injected mice, as well as prevented infiltration of macrophages, CD4+, and CD8+ T cells into the islets. Significantly, SD1 and SD11 suppressed the levels of IL1-β, TNF-α and IFN-γ and increased IL-10, which is concomitant with the inhibition of cleaved caspase 3, caspase 9, caspase 8, proapoptotic Bax, NF-κBp65, pSTAT1, and iNOS. Additionally, the survival ability of β-cells was mediated by upregulated anti-apoptotic Bcl2. We conclude that SD1 and SD11 attenuate STZ-induced diabetic mice by stabilizing glycemic levels and reducing inflammation, thereby protecting β-cells. Among the probiotic treatment groups, SD11 revealed the best results in almost all parameters, indicating its potential use for alleviating hyperglycemia-associated symptoms.
Copyright: © 2023 Nopparat et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.