LPS, or Endotoxins, are not all bad

Here’s one for the gut health nerds.

Is LPS that bad?

As humans, we want to classify things as good or bad. In many cases, it’s not that simple. This is true of the much aligned gut microbial lipopolysaccharide, or LPS, also known as endotoxins.

It’s true that too much LPS can cause inflammation, fever and septic shock, potentially even leading to death.

But LPS is thought to be one of the most potent activators of innate immune signalling and an important mediator of the microbiome’s influence on the health of the host.

TLR4 immune signalling and silencing

It does this via Toll-like receptor 4 (TLR4), a genetically encoded protein. Its activation leads to inflammatory cytokine production, which is responsible for activating the innate immune system we are born with. This process is so important that in 2011, the Nobel prize was given to Bruce Beutler for his discovery that the LPS receptor IS in fact TLR4.

Other research suggests that it plays an immune silencing role, stopping TLR4 signalling for the entire gamut of organisms inhabiting the human gut. This immune silencing is also considered healthy in adults.

Small doses of LPS therefore appear to be important for both immune stimulation and silencing.

Hexa, Penta and Tetra LPS

Beyond this, did you know there is more than one kind of LPS? There are Hexa, Tetra and Penta.

Tetra and Penta TLRs can be anti-inflammatory. Recognised by the TLR2 signal pathway (not 4), they help commensal or beneficial bacteria we rely on for our health, to establish themselves. LPS thus plays a vital role in bacterial virulence.

What does this mean for you?

Research shows you can influence LPS activity in your gut through your diet.

A study on people with type 1 diabetes showed that healthy food choices like fish, fresh vegetables, fruits and berries may reduce endotoxaemia caused by LPS and lead to good health outcomes.

Once again, the power of food! This reminds me that we’re made up of complex systems we can study forever, but that eating real food and living a healthy lifestyle are what’s most important to our health.