Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2017 Jul 28;8:838. doi: 10.3389/fimmu.2017.00838

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2017 Statovci, Aguilera, MacSharry and Melgar.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

Schematic illustrating the nutrient factors regulating microbial and host responses in the healthy gut and lung. Homeostatic balance at the mucosa due to a balanced diet rich in fiber allows for regulated interactions between the epithelia and the microbiome. This dialog with the microbiome allows for appropriate epithelial barrier function, mucus secretion, and underlying immune sensing. In the gut, a balanced microbiome generates SCFAs and dietary long chain FAs and the fat-soluble vitamins A and D which induce a tolerogenic mucosal immune state locally at the gut but also systemically and particularly in the lung. The gut-derived SCFAs acetate and propionate enhance DCs, ILC, and macrophage phagocytic function and Tregs balance resulting in the control of lung microbiota and efficient mucocillary clearance of inhaled microbes and particulates. Lung figure adapted from Ref. (41). Abbreviations: CCR9, C–C motif chemokine receptor 9; DCs, dendritic cells; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; FAs, fatty acids; GC, goblet cells; GPR, G-protein coupled receptor; ILC, innate lymphoid cells; α4β7, integrin α4β7; IL-1β, interleukin 1 beta; IL-4, interleukin 4; IL-5, interleukin 5; IL-10, interleukin 10; Fe2⁺, iron; MΦ, macrophage; NFκB, nuclear factor kappa-light-chain-enhancer of activated B cells; PPARγ, peroxisome proliferator-activated receptor gamma; RA, retinoic acid; SCFAs, short-chain fatty acids; TGFβ, transforming growth factor beta; Th, T helper; Tregs, T regulatory cells; TLR4, toll-like receptor 4; VitA, vitamin A; VitD, vitamin D; VDR, vitamin D receptor; healthy bacteria phyla—, bacteroides; , firmicutes; , barrier integrity.

Inline graphic — Schematic illustrating the nutrient factors regulating microbial and host responses in the healthy gut and lung. Homeostatic balance at the mucosa due to a balanced diet rich in fiber allows for regulated interactions between the epithelia and the microbiome. This dialog with the microbiome allows for appropriate epithelial barrier function, mucus secretion, and underlying immune sensing. In the gut, a balanced microbiome generates SCFAs and dietary long chain FAs and the fat-soluble vitamins A and D which induce a tolerogenic mucosal immune state locally at the gut but also systemically and particularly in the lung. The gut-derived SCFAs acetate and propionate enhance DCs, ILC, and macrophage phagocytic function and Tregs balance resulting in the control of lung microbiota and efficient mucocillary clearance of inhaled microbes and particulates. Lung figure adapted from Ref. (41). Abbreviations: CCR9, C–C motif chemokine receptor 9; DCs, dendritic cells; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; FAs, fatty acids; GC, goblet cells; GPR, G-protein coupled receptor; ILC, innate lymphoid cells; α4β7, integrin α4β7; IL-1β, interleukin 1 beta; IL-4, interleukin 4; IL-5, interleukin 5; IL-10, interleukin 10; Fe2⁺, iron; MΦ, macrophage; NFκB, nuclear factor kappa-light-chain-enhancer of activated B cells; PPARγ, peroxisome proliferator-activated receptor gamma; RA, retinoic acid; SCFAs, short-chain fatty acids; TGFβ, transforming growth factor beta; Th, T helper; Tregs, T regulatory cells; TLR4, toll-like receptor 4; VitA, vitamin A; VitD, vitamin D; VDR, vitamin D receptor; healthy bacteria phyla—, bacteroides; , firmicutes; , barrier integrity.