2 replies to this topic

[Michael Lustgarten]

[albedo]

Thank you Michael. Very interesting. Please allow me (sorry, long) citing this work (which in turn cites Trompette et al 2018 you used in your video). Incidentally, I have a keen interest to lung microbiota too and potential interventions/modulation in that organ, just in case you spot something related in future:

 

"...Our findings are in line with the emerging concept whereby gut SCFAs remotely influence immune responses in the lungs and can modulate disease outcomes, including asthmatic reactions (Cait et al., 2018; Maslowski et al., 2009; Trompette et al., 2014) and respiratory viral and bacterial infections (Antunes et al., 2019; Chakraborty et al., 2017; Galv~ao et al., 2018; Moriyama and Ichinohe, 2019; Trompette et al., 2018). The SCFAs’ potential role in innate immune defenses against respiratory infections has yet to be characterized in detail. Importantly, acetate supplementation reduced, in a FFAR2-dependent manner, the bacterial burden after the episode of influenza, despite the immunosuppressive environment imposed by IAV. Of importance, this translated into reduced lung pathology and improved survival rate of double-infected mice.  Manipulation of the gut microbiota (which, as we show, becomes deleterious during influenza) might represent an interesting option to limit post-influenza bacterial superinfections. Importantly, Trompette and collaborators have demonstrated that preventive supplementation of diets enriched in fibers protected against influenza infection (lower virus load and pathology) (Trompette et al., 2018). This treatment is associated with enhanced frequency of Bifidobacterium and Bacteroides genus and enhanced levels of SCFAs (particularly butyrate). Remarkably, butyrate controls influenza infection by reducing, through enhanced CD8+ T cell activity, viral replication. This report is fully in line with our current study, although the consequences of high-fiber diets (or acetate-yielding diets) on secondary bacterial infections are presently unknown. Preventive consumption of fermentable fibers, by protecting the SCFA-producing compartment, may maintain intestinal homeostasis and reinforce the lung’s defenses (against IAV and bacteria) during influenza. In the same line, probiotics (e.g., SCFA producers such as the Bifidobacteria and Lactobacillus spp) have been successfully used in the context of IAV infection (Zelaya et al., 2016), although their impact on superinfection was not characterized. In the future, strategies that seek to harness the power of the gut microbiota (via pre-/probiotics) to manage influenza infections might help to control both viral diseases and the harmful viral/bacterial synergy during bacterial superinfections. Alternatively, the use of SCFAs or FFAR2 agonists as therapeutics might be envisaged to lower bacterial superinfection post-influenza. FFAR2 agonists are viewed as a promising treatment of metabolic syndromes such as type 2 diabetes and obesity (Milligan et al., 2017; Ulven, 2012). Our study shows the positive effect of a synthetic FFAR2 agonist in respiratory infection and highlights a new opportunity for further development against bacterial pneumonia..." (bold mine)

 

Sencio V, Barthelemy A, Tavares LP, et al. Gut dysbiosis during influenza contributes to pulmonary pneumococcal superinfection through altered short-chain fatty acid production. Cell Reports. 2020;30(9):2934-2947.e6.

 

(edit: spelling)

Edited by albedo, 22 February 2021 - 05:26 PM.

[albedo]

I am amazed at Evans et al 2014 realizing how the risk decreases for cancer (and cardiovascular) while pneumonia increases for the very old !