Butyrate Produced by the Gut Microbiome Encourages Favorable Macrophage Polarization

The gut microbiome produces a broad range of necessary, beneficial metabolites, but the effects of only a few are well understood. Butyrate is one of the better studied of these metabolites, particularly in the context of cognitive function. Butyrate encourages BDNF expression, which in turn upregulates neurogenesis. Butyrate also upregulates expression of FGF21, which adjusts metabolism in ways that mimic some of the beneficial effects of calorie restriction. Unfortunately, shifts in the balance of populations in the gut microbiome take place with age, and butyrate production decreases as a result. The innate immune cells called macrophages adopt packages of behaviors known as polarizations in response to circumstances. In today's open access paper, researchers note that butyrate adjusts the polarization of macrophage cells, from the pro-inflammatory M1 polarization to the anti-inflammatory, pro-regenerative M2 polarization. This is generally advantageous in the context of aged, inflamed tissue that tends towards fibrosis. Fibrosis is a malfunction of normal tissue maintenance that leads to scar-like deposition of collagen extracellular matrix, degrading tissue function. Organs such as the heart and kidney suffer fibrosis in later life, and there is presently little that can be done about that after the fact. A number of lines of work have shown that adjusting macrophage polarization towards M2, to dampen inflammation, can be beneficial in fibrotic tissues, however, a...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs