Gut microbes contribute to age-associated inflammation, mouse study shows

Source: ScienceDaily

Date: April 12th, 2017

https://www.sciencedaily.com/releases/2017/04/170412132332.htm

Summary: Currently, the only ways for us to reduce the severity and risk of age-associated inflammation is to eat healthy and exercise. If you suffer from chronic inflammation, consulting your doctor is also helpful. As we age, we usually have an increase in tumor necrosis factor (TNF) and other pro-inflammatory cytokines. It turns out this may be related to the fact our intestinal walls become much more permeable as we age due to changes in the gut microbiome, and as a result, bacterial products that shouldn’t “leak through” do (or at least, this is what they are discovering in mice). This escape of microbial products out of the GI tract triggers an immune response (inflammation) and weakens the immune system. Researchers believe if we can maintain a healthy gut microbiome, we can reduce age-associated inflammation and prevent this cascade events before they start. However, which bacteria in the gut lead its increased permeability is unknown, as is when in life the gut microbiome changes enough for this to occur.

Connections: Just the other day, we covered the pros and cons of inflammatory responses triggered by the immune system. While localized inflammation is usually a good thing, systematic inflammation is not, as it often causes high fever, a massive drop in blood pressure, and results in death for 30% of people affected.

Critical Analysis: It continually amazes me how greatly our microbiome impacts our health. It doesn’t surprise me that it plays a crucial role in the aging process, but I had never considered it before. The health of our immune system is obviously important as we age, and most know its efficacy declines as we get older, but the fact that this decline could partially stem from changes in our gut microbiome is fascinating! This could mean that probiotics, assuming they determine which bacteria are at fault for breaking down the intestinal barriers, could enhance our immune system as we age. I do think this article is scientifically accurate and overall, does a good job of describing complex scientific principles to the general public, as it explains most of the science in general terms and makes it clear why this could have important implications as we age.

Question: This team of researchers said they are setting out to identify the “bad” bacteria that induce the breakdown of intestinal barriers, but I was wondering if the scientific community already knows of some particularly useful or harmful bacteria in our guts that could play a role in this process? Or is this such a brand new idea that nobody has any hypotheses? If no specific bacteria are known, what kind of chemical products would these “bad” bacteria release to weaken our intestinal walls?

2 Comments for “A2: Microbes in the News”

caito

says:

This is an interesting concept, and one with directly usable application if it can be applied correctly. I think the biggest hurdle would be to identify and sort the all the ‘bad’ bacteria versus the ‘good’ bacteria.
I think there may be more to the idea of proportions of good versus bad than just the presence of certain bacteria. Maintaining that sort of balance might be difficult to do, if it can even be practically achieved in humans. Also, I don’t think this article touched on the fact that there are three different microbiomes people typically develop naturally, and that there may be people already predisposed for certain proportions of bad or good organisms.

ajgarner2

I think you bring up a valid concern in that this might not even be feasible, or if it is, far more complex because people have a variety of different gut microbiomes. If this research moves to studying human intestinal bacteria, they’d have to consider the predominant microbial communities found in people. It is an interesting concept nonetheless!