Plant-Derived Exosomal MicroRNAs Shape the Gut Microbiota.
Teng Y, Ren Y, Sayed M, Hu X, Lei C, Kumar A, Hutchins E, Mu J, Deng Z, Luo C, Sundaram K, Sriwastva MK, Zhang L, Hsieh M, Reiman R, Haribabu B, Yan J, Jala VR, Miller DM, Van Keuren-Jensen K, Merchant ML, McClain CJ, Park JW, Egilmez NK, Zhang HG
Cell Host Microbe. Nov 2018
COMMENT: It is known that diet can alter the gut microbiota. For that, it could be used to mitigate disease. In this study, the authors proposes a mechanism which could ameliorate mouse colitis (induced by dextran sulfate sodium (DSS)).
We demonstrate that plant-derived exosome-like nanoparticles (ELNs) are taken up by the gut microbiota and contain RNAs that alter microbiome composition and host physiology
In this article, the authors mainly wanted to answer the following questions:
- Can ELNs be taken up by gut bacteria?
- Upon taking up the ELNs, can diet-derived ELN-RNAs affect the biology of gut bacteria?
Ginger ELNs (GELNs), which contain RNAs, taken up by gut bacteria could result in a change of microbiome composition with impact in host physiology. GELNs are preferentially taken up by Lactobacillaceae.
A kind of Lactobacillaceae, Lactobacillus rhamnosus (LGG) has mainly uptaken phosphatidic acid (PA)-enriched GELNs. These GELNs contain microRNAs that could regulate LGG metabolites.
RNA sequence analysis further revealed that GELN-RNAs harboring the complementary seed-matching sequence of LGG mRNA have the potential for binding gut bacterial mRNA
LGG metabolizes tryptophan to indole derivates. GELN-RNAs inhibit the expression of monooxygenase ycnE in LGG, that leads to an inhibition of indole-3 acetamide (I3AM) and induction of indole-3-carboxaldehyde (I3A).
I3A acts as a ligand for aryl hydrocarbon receptor (AHR), inducing local production of IL-22, which is implicated in the maintenance of the intestinal barrier function. This process elicits antimicrobial immunity and tissue repair at barrier surfaces.
In this work, the authors noticed that those mice fed with GELN-RNAs had more protection against DSS-induced mouse colitis, suggesting that this protective effect is GELN-RNA specific.
In conclusion, given the importance of gut microbiota in human physiology, our findings reveal an important molecular mechanism underlying how diet ELN miRNAs can cross talk with gut microbiota to maintain gut health. Because the composition of diet-derived ELN miRNAs and lipids is different among diets and each ELN miRNA has targets specific bacterial mRNA, this feature could be utilized for specific manipulation of the microbiome for human health and treatment of dysbiosis- related disease