THE ROLE OF FISH IN GUT HEALTH 

Authored by: Shadae Zamyad, Nutritionist

Did you know that your digestive health impacts not only how your body absorbs nutrients but also your immune system and even your mental health? Gut health and the microbiome have been major buzzwords in the health and wellness world lately. We constantly hear about the importance of consuming green vegetables, pickled and fermented foods, and pre- and probiotics for maintaining a healthy gut. But one superfood – seafood - has been largely overlooked in the gut health conversation, and it's time for that to change.

Fish deserves a lot more attention for its proven and unique benefits for our digestive health. The Omega-3 fatty acids and easily digestible proteins in fish help reduce gut inflammation and support smoother digestion, making it an excellent choice for maintaining a healthy digestive system. Packed with high-quality, easily digestible protein, anti-inflammatory Omega-3 fatty acids, and a wide array of essential nutrients, fish is a true powerhouse for optimizing gut health. Let's dive deeper into the many ways that incorporating more fish into your diet can supercharge your digestive wellness and overall health!

Promoting Gut Microbiota Diversity

The gut microbiome, a community of microorganisms in your digestive tract, plays a crucial role in overall health. A diverse microbiota supports a healthy gut, and fish can help. Studies show that Omega-3 fatty acids and bioactive peptides in fish encourage the growth of beneficial gut bacteria (Costantini et al., 2017). When fish protein is broken down during digestion, it releases special compounds called bioactive peptides which are short chains of amino acids that can actively influence our health. Research has shown that fish-derived peptides can change the gut microbiota composition by acting as prebiotics, which are nourishing beneficial bacteria that can help increase gut microbiota (Akbarian et al., 2022). 

Additionally, the Omega-3 fatty acids contained in fish can influence gut microbiota as well! A recent study published by the National Library of Medicine explored the impact of Omega-3 rich diets on the gut microbiota. Results indicated that regular consumption of Omega-3 fatty acids from fish can help increase good gut bacteria such as bifidobacteria and lactobacillus which both help promote better gut health and digestion, while reducing the abundance of potentially harmful bacteria (Noriega et al.,2016). This finding is significant because a balanced gut microbiome is crucial for maintaining optimal gut health and preventing digestive issues (Costantini et al., 2017). 

Fish such as Black Cod (aka Sablefish), sardines or mackerel as well as oysters and seaweed are particularly high in those good Omega-3 fats, especially beneficial EPA and DHA. Plant sources such as walnuts, hemp seeds or flax seeds are also rich in ALA Omega-3. However, the body can’t readily use this plant-derived Omega-3 and has to convert it first; but can typically only convert a small percentage of it. Marine sources of Omega-3 are thus deemed more effective and beneficial for our overall health. Though, when it comes to the gut microbiome, eating a broad variety of foods is best. So why not eat both? 

How Omega-3s Reducing Gut Inflammation

Inflammation is a pervasive and debilitating problem for the millions of people worldwide who suffer from conditions like Inflammatory Bowel Disease (IBD), Crohn's disease, and ulcerative colitis. These chronic digestive disorders can be incredibly life-limiting, causing severe abdominal pain, frequent diarrhea, weight loss, fatigue, and a dramatically reduced quality of life. In the United States alone, it's estimated that 1.6 million individuals grapple with the physical and emotional toll of IBD, while millions more suffer silently around the globe. Living with constant bloating and constipation is not normal, and it's a sign that your gut health needs attention. While many factors can contribute to these issues, diet plays a crucial role. Processed foods, lack of fiber, and other dietary factors can slow down gut motility and lead to these uncomfortable symptoms.

While there is usually no single fix to gut health issues, there are things we can do with our diet to bring about improvement – eating more fiber, a broad variety of vegetables and whole foods, fermented foods, and fish. Regular fish consumption has been shown to improve gut motility, reducing bloating and constipation. Fish is a great source of complete proteins that are highly bioavailable along with many vitamins and minerals that support overall gut health. Fish is also an excellent source of Omega-3 fatty acids, which have anti-inflammatory properties that can help soothe the digestive tract. 

The two most potent Omega-3s, EPA and DHA, found abundantly in fish, have been shown to work wonders in reducing the chronic inflammation that fuels the painful symptoms and tissue damage associated with IBD and similar conditions. An interesting study by the National Library of Medicine investigated the anti-inflammatory properties of Omega-3 fatty acids, specifically EPA and DHA. The findings indicated that these Omega-3s regulate various inflammatory processes in the body, including those within the gut. Given that chronic inflammation is a key factor in many digestive disorders, such as Inflammatory Bowel Disease (IBD), the researchers concluded that the anti-inflammatory effects of Omega-3s in fish may play a crucial role in alleviating symptoms and promoting gut healing (Calder et al., 2017). 

Prevent Digestive Disorders

Regular fish consumption has been linked to a lower risk of digestive disorders, including colorectal cancer. A 2020 study published in the Clinical Gastroenterology and Hepatology attributed this to Omega-3s’ anti-inflammatory effects in fish that can help reduce risk of colorectal cancer (Aglao et al. 2020). By targeting inflammation, a key driver in the development of various gastrointestinal disorders, Omega-3 fatty acids demonstrate a unique ability to shield the gut from potential harm.

The implications of this research extend beyond colorectal cancer prevention. This study serves as a compelling reminder of the profound impact our dietary choices can have on our digestive well-being. Embracing the consumption of fish, rich in Omega-3s, may not only reduce the risk of severe conditions like colorectal cancer but also contribute to a more balanced and thriving digestive system overall. Another study published in Scientific Reports also showed that Omega-3 fatty acids from fish reduce inflammation and support a healthier microbiome, and showed that this is because Omega-3s decrease pro-inflammatory cytokines in the gut (Menni et al.,2016). 

The Power of Fish: Omega-3s, Bioactive Peptides & Gut Health

Fish is a true superfood when it comes to digestive health, offering a wide array of benefits that can help keep your gut happy and functioning at its best. The Omega-3 fatty acids found in fish can help promote a diverse and balanced gut microbiome. In addition to its Omega-3 content, fish is also an excellent source of easily digestible protein and bioactive peptides. These components work together to enhance enzyme activity and improve gut motility, ensuring that food moves smoothly through the digestive tract and nutrients are efficiently absorbed. Incorporating more fish into your meals can provide your body with these gut-supporting nutrients while keeping your consumption of unhealthy fats in check!

Here on the West Coast, we have access to some of the best fish in the world – wild, sustainable, clean and delicious species with the optimal nutrient content to promote good gut health. Local wild Black Cod (also known as Sablefish) has some of the highest Omega-3 levels of any seafood in the world, bringing in 1,137mg of Omega-3s (DHA + EPA) per 100 calories of fillet, which is about twice as much as wild King salmon. And even leaner white fish species like Widow Rockfish, Thornyhead or Lingcod contain great Omega-3 levels that your gut microbiome will appreciate.

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Common Questions

References

Aglago, E. K., Huybrechts, I., Murphy, N., Casagrande, C., Nicolas, G., Pischon, T., Fedirko, V., Severi, G., Boutron-Ruault, M. C., Fournier, A., Katzke, V., Kühn, T., Olsen, A., Tjønneland, A., Dahm, C. C., Overvad, K., Lasheras, C., Agudo, A., Sánchez, M. J., ... Gunter, M. J. (2020). Consumption of fish and long-chain n-3 polyunsaturated fatty acids is associated with reduced risk of colorectal cancer in a large European cohort. Clinical Gastroenterology and Hepatology, 18(3), 654–666.e6. https://doi.org/10.1016/j.cgh.2019.06.031

Akbarian, M., Mirzaei, M., Berenjian, A., Nezhad, M. H., Jafari, M., & Nikzad, M. (2022). Bioactive peptides: Synthesis, sources, applications, and proposed mechanisms of action. International Journal of Molecular Sciences, 23(3), 1445. https://doi.org/10.3390/ijms23031445 

Calder, P. C. (2017). Omega-3 fatty acids and inflammatory processes: From molecules to man. Biochemical Society Transactions, 45(5), 1105–1115. https://doi.org/10.1042/BST20160474

Costantini, L., Molinari, R., Farinon, B., & Merendino, N. (2017). Impact of omega-3 fatty acids on the gut microbiota. International Journal of Molecular Sciences, 18(12), 2645. https://doi.org/10.3390/ijms18122645

Menni, C., Zierer, J., Pallister, T., Jackson, M. A., Long, T., Mohney, R. P., Steves, C. J., Spector, T. D., & Valdes, A. M. (2017). Omega-3 fatty acids correlate with gut microbiome diversity and production of N-carbamylglutamate in middle aged and elderly women. Scientific Reports, 7, 11079. https://doi.org/10.1038/s41598-017-10382-2

Noriega, B. S., Sanchez-Gonzalez, M. A., Salyakina, D., & Coffman, J. (2016). Understanding the impact of omega-3 rich diet on the gut microbiota. Case Reports in Medicine, 2016, 3089303. https://doi.org/10.1155/2016/3089303