Thursday, April 23, 2020

Hiding in plain sight: Gut health

by Karin Pittman 1,2, Sjur Øyen S1, Mette Sørensen3, Kjetil Korsnes 3,4, Dalia Dahle3, Nimalan Nadanasabesan 3, Mearge Okubamichael2, Grigory Merkin G2, Ole Jacob Myre2
1. Dept of Biosciences, Univ of Bergen, Thormøhlensgate 53, 5006 Bergen, Norway
2. Quantidoc AS, Thormøhlensgate 41, 5006 Bergen Norway
3. Nord University, P.O. Box 1490, 8049 Bodø, Norway
4. BioVivo Technologies AS, Storbjørnen 17, 8029 Bodø, Norway


Fish wear their immune system on the outside and the answer to many industry conundrums is likely hiding in plain sight. This statement refers to the mucosal immune system, or rather all the slimy barriers in skin, gills and intestines (the outside of the inside), (See Figures 1A and 1B).

Why does this matter? We can think of this protection like a detective’s tools to find out where a production challenge lies: the skin is the shield and able to tolerate some handling and damage, the gills are the sentinel guarding 50 percent of the surface area of the fish, while the guts are the foundation, reliant on incoming nutrition upon which almost all else in the fish is built.
 

The structure of skin, gill and gut mucosal barriers at the cell-level is almost identical. These tissues can regenerate, and they can learn: this innate mucosal (mucus) immune system is more important for fish than the typical acquired immune system is for mammals. Fish are hatched with this protective system, optimised quite free-of-charge by nature through about 500 million years of evolution. It knows a thing or two about protecting fish health, survival and tolerance.

If we can read these immune responses, so what? Feeds give different signals to the guts and the skin, and sometimes to the gills. Everyone knows about the anti-nutrients that come from terrestrial plantstuffs, and everyone knows that fishmeal is generally more expensive than plant ingredients.

Fish gut microbiomes are clearly different from mammalian gut microbiomes and fish genes even more diverse than mammalian genes. This makes functional interpretation a challenge, but we have to start somewhere. To summarise the effects of genes, fatty acids, proteins, lipids and treatments we can look at the tissue which contains the cells we are interested in, the mucus or goblet cells.

This is a much higher level of biological organisation than genes and it is much less variable. The fish intestine reacts to the entirety of a recipe, not just the fashionable silver bullet ingredient.

Read more, HERE.


The Aquaculturists

1 comment:

  1. Nice post. Well what can I say is that these is an interesting and very informative topic on tummy health

    ReplyDelete