Probiotic Lactobacillus rhamnosus GG Promotes Mouse Gut Microbiota Diversity and T Cell Differentiation

Abstract

Lactic acid bacteria (LAB) are the primary genera of the intestinal flora and have many probiotic functions. In the present study, Lactobacillus rhamnosus GG (LGG) ATCC 53103 was used to treat BALB/c mice. After LGG intervention, both low and high LGG doses were shown to improve the observed OTU, Chao1, ACE, and Shannon indices, while the Simpson index decreased, demonstrating that LGG can promote intestinal microbiota abundance and diversity. Furthermore, LGG treatment increased the abundances of intestinal Firmicutes, Bacteroides and Actinomycetes while reducing that of Proteobacteria. In addition to its effect on gut the microbiota, LGG could also regulate the host immune system. In the present study, we showed that LGG could affect the percentage of CD3+ T lymphocytes in the spleens (SPLs), mesenteric lymph nodes (MLNs), Peyer’s patches (PPs) and lamina propria lymphocytes (LPLs) of mice, including total CD3+ T, CD3+CD4+ T, and CD3+CD8+ T lymphocytes. Furthermore, LGG could effectively increase the expression of Th1-type cytokines (IFN-γ) and Th2 cytokines (IL-4) in CD4+ T cells, indicating that the proportion of Th1 and Th2 cells in mice with LGG treatment was in a high equilibrium state compared to the control group. In addition, the IFN-γ/IL-4 ratio was greater than 1 in mice with LGG intervention, suggesting that LGG tends to mediate the Th1 immune response. The results of the present study also showed that LGG upregulated the expression of IL-17 in CD4+ T cells and regulated the percentage of CD4+CD25+Foxp3+ Treg cells in various secondary immunological organs, indicating that LGG may promote the balance of Th-17 and Treg cells.

Randomised, double-blind, placebo-controlled trial of Probiotics To Eliminate COVID-19 Transmission in Exposed Household Contacts (PROTECT-EHC): a clinical trial protocol

“…Most clinical trials employing probiotics focus on clinical outcomes but lack quantitative microbiome data. However, LGG has been associated with changes in microbiota composition in mouse studies, 25 26 and human studies of other Lactobacillus spp have demonstrated that probiotic administration significantly alters the gut microbiota 27 28 ; therefore, further studies such as ours are needed to elucidate its effects of LGG specifically on the human microbiome. In the interest of social distancing, we are employing a novel approach to conduct the study entirely remotely; this also allows us to recruit participants nationally across the USA.…”

Gut Microbiota and Immune Modulatory Properties of Human Breast Milk Streptococcus salivarius and S. parasanguinis Strains

“…Inoculating commensal bacteria into mice allows to study how bacteria influence the gut microbiota and host immunity in vivo (21)(22)(23). In vitro human peripheral blood mononuclear cells (PBMCs) and intestinal epithelial cells are widely used to evaluate the anti-/proinflammatory potential of bacteria in humans (24,25).…”

The Effects of Single Strains and Mixtures of Probiotic Bacteria on Immune Profile in Liver, Spleen, and Peripheral Blood

“…LGG has been previously shown to increase the percentage of the TH17 cells when co-cultured with human PBMCs ( 48 ). Also, a higher percentage of the TH17 cells was observed in the spleens of LGG groups when compared to that of the control groups in Shi et al's study ( 49 ). In contrast, the probiotic strains, Enterococcus faecalis FK-23 and Bifidobacterium infantis , have been associated with a reduced TH17-immune-response in different animal models ( 50 , 51 ).…”