A dietary supplement protects the lives of farm shrimp

Brine shrimp which were fed a compound called poly-ß-hydroxybutyrate (PHB) were prevented from becoming infected with pathogenic bacteria. Professor Willy Verstraete and colleagues at Ghent University in Belgium reported these findings in the February issue of ‘Environmental Microbiology’.

The bacteria Vibrio campbellii are antibiotic resistant and cause significant loss in the fish farming industry (aquaculture) as an outbreak cannot be treated with antibiotics. Adding PHB to the culture water significantly decreased the number of brine shrimp which were killed by Vibrio campbellii. The shrimp had ‘eaten’ the PHB and become protected from infection.

PHB is a naturally-occurring compound which is produced and used by microbes as a form of energy storage. It is metabolised when other common energy sources are not available. It is also a source of butyrate which keeps the gut healthy.

“We recently found that PHB-containing bacteria can also be used to protect the shrimp from the vibrios (without extracting the compound from the bacteria) and we are currently testing the potential of such microbes in other animal models. Given the fact that PHB can be produced on an industrial scale for a reasonable price, PHB addition to animal diets would be an alternative to antibiotics that is not only effective, but also economically attractive. In this respect, our findings might contribute to a more sustainable animal production.” said Professor Verstraete and his collaborator Tom Defoirdt.

This finding has important implications for infection reduction, not only in fish farming, as we may be able to reduce, or even replace the use of antibiotics. The ecological and health benefits in avoiding the use of antibiotics are many-fold. It may even be possible to protect other organisms from pathogenic bacteria using a dietary supplement based on this microbial storage product.