(In 2 minutes I found something about gut bacteria)
Gut instinct
HEALTH
The Nofima notebook: 2 of 9
by
Dr Shruti Gupta
14 April 2020, at 10:41am
Microbiome scientists at Nofima are working on uncovering the complex cross-talk between the fish and its microbes and aim to improve the health of farmed fish.
Microbiome: an organ in its own right
The hundreds of trillions of microbes that reside on and within animals, including fish, are collectively referred to as the microbiota. These complex microbial communities, which interact with each other, the host and the host’s environment, are called the microbiome.
At Nofima, I work with a group of scientists who are collaborating to explore the influence of the microbiome, associated with its dietary effects in aquaculture. Currently, our research is focusing on investigating the effects of the microbiome on system performance.
Preparing gut bacteria for analysis
© Nofima
Why should we study the fish microbiome?
The highly complex and mixed microbial population which lives in the intestine of animals is known as the gut microbiota. A stable and resilient microbiome is linked to maintaining the overall health and well‐being of the host. Many efforts have already been directed to understand the interactions between host and microbe, as well as between microbes themselves, in humans and other terrestrial animals. Now we know that gut microbiota plays a crucial role in supporting the host’s intestinal stability as well as metabolic and immune functions. As with humans and other animals, the gut microbial communities of lower vertebrates such as fish can also contribute to maintaining the host organism’s immune equilibrium, digestion and nutrition.
The fish microbiota is diverse and includes protists, bacteria, archaea, fungi and viruses. It is shaped by several host-associated factors – such as diet, age, geographical location, stress, genetics and drugs. Among the microbial communities in a fish’s gut, bacteria are the most abundant and dominant microorganisms. They maintain an intimate relationship with the gut mucosa (the inner lining of the gastrointestinal tract) and impart substantial functions in a healthy individual – they co-exist to contribute, among many functions, to the production of vitamins, synthesis of amino acids and production of bacterial metabolites.
Nofima’s strategy to investigate the fish microbiome
Many aspects of fish microbiome research are still something of a black box, as researchers remain uncertain about how, when and where the fish acquires its microbiota. We need this information in order to maximise the potential of this new field in aquaculture. Microbiome research is inherently interdisciplinary and
Nofima has a special advantage since its work ecompasses disciplines such as fish health, nutrition, genetics, production biology and food processing – all of which can collaborate in opening up the black box.
The majority of previous studies have focused upon the structure of the fish microbiome, providing little knowledge about the immense functional potential of the gut microbiome. At Nofima, some of our objectives are to understand and study how the microbiome cooperatively functions as communities in different rearing environments (eg its effect on biofilter activity) and how it interacts with the host tissue (that is, its role in nutrient conversion, health and disease). Furthermore, we aim to pinpoint key functionalities of these microbes in the host, which could be of great value for the future development of the aquaculture sector. In addition, fish diseases are one of the largest challenges in aquaculture production, and, as a sector, when we commit to addressing them, our highest priority tends to be working to identify the single pathogenic microbe causing the disease. At Nofima, by contrast, we challenge the status quo to identify the rest of the microbiota and determine if they can confer some resistance to the pathogen.
In the face of rapidly progressive deterioration of skin health, studies aim to get a deeper understanding of the role of the microbiome and the mechanisms of disease resistance. In recent years, dietary studies have shown that variation in microbiome composition is mainly driven by certain bacteria, but these types of bacteria are not always the same between studies. At the same time, changes are also seen to occur in circumstances where there is a high level of connectivity to external microbiomes (eg contact with varied microbes from the surrounding water or from other fish living in the same tank). A limitation is that we have not yet measured absolute microbial cell numbers in the intestine. Investigations into defining underlying mechanisms of host-microbe interactions are currently being developed at Nofima.
If you get bored, you can read all you want about how gut bacteria affects fish health.
Here is another excerpt:
It's by these guys if you want to read the whole article, but it's long:
REVIEW article
Front. Microbiol., 04 May 2018 |
https://doi.org/10.3389/fmicb.2018.00873
The Gut Microbiota of Marine Fish
Sian Egerton1,2,
Sarah Culloty2,3,
Jason Whooley4,
Catherine Stanton5,6 and
R. Paul Ross1,5,6*
- 1School of Microbiology, University College Cork, Cork, Ireland
- 2School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- 3Environmental Research Institute, University College Cork, Cork, Ireland
- 4Bio-marine Ingredients Ireland Ltd., Killybegs, Ireland
- 5Teagasc Research Centre, Fermoy, Ireland
- 6APC Microbiome Ireland, Teagasc and University College Cork, Cork, Ireland
A Historical Overview
Fish and other marine animals have a unique and intimate interaction with their surrounding environment and, in turn, with the microorganisms that co-exist there. The world’s oceans are teeming with microorganisms. It is estimated that 3.6 × 1030 microbial cells account for more than 90% of the total oceanic biomass, while the number of viral particles may be one hundred fold greater (
International Council for the Exploration of the Sea [ICES], 2011). The relationship that fish have with surrounding microorganisms can be mutualistic or pathogenic. Like humans and other mammals, fishes’ associated symbiotic gut microbiota play a role in nutritional provisioning, metabolic homeostasis and immune defence (
Gómez and Balcázar, 2008;
Sullam et al., 2012).
