Mucilage: what is it?

Working on the Doggy Delly sprouting experiments soon made it evident that chia seeds can’t be sprouted in water in the same way as legumes, for example. This is because of the gelatinous layer created when they are soaked, which is known as mucilage. Interestingly, although it presents challenges for sprouting, that discovery opened up a whole new avenue for exploring the functional benefits of mucilage for dogs, including its use for texture in baked training treats.

For the linguists among us, yes – that’s from the same (Latin) root as mucus, meaning slippery or slimy. Probably not a very attractive association. Moving on…

What is mucilage?

Mucilage is bioactive, biodegradable, non-toxic and environmentally friendly. This soluble dietary fibre occurs as a natural jelly-like substance in some plants or in others after treatment with water, as in the case of my chia seeds. The purpose of mucilage is to protect plants against environmental stressors, enhance the uptake and retention of water and help the germination process. In the kitchen, for example, we can see how chia seeds will swell up as they absorb fluid; in other words, it’s what puts the pudding in a chia pudding!

Applications

Commercial use of mucilages is nothing new. They have been used as an additive, stabiliser, and emulsifier and even in high performance biodegradable food packaging materials such as coatings, in textiles and in the production of paint.

But more recently, given their pro-health benefits, mucilages have become the focus of increasing interest in the rapidly-growing nutraceutical and functional food markets. This is due not only to their attraction as a source of nutrients and phytochemicals[1], but also their potential as a replacement for fat and gluten and even reported pharmaceutical, medicinal and cosmetic applications.

Sources

There are many sources of plant-derived mucilages, with the most suitable for dogs being chia seeds, flax seeds, psyllium, fenugreek and arugula. While the specific composition of mucilages can vary from one plant species to the next[2], from a chemical perspective, they are mainly large molecules which typically contain polysaccharides such as pectin, cellulose and xylan, as well as glycoproteins and other bioactive compounds. Mucilages can contribute to overall health by acting as a prebiotic, helping to manage cholesterol or by regulating bowel movements. Studies have looked at the health benefits of mucilage[3] as a functional food and its applications in nutraceuticals and prebiotics.

Benefits at a glance

The benefits of any particular mucilage will depend on which seeds you are using. But overall, benefits include:

  • Soothes sensitive stomachs and irritated intestinal linings, promoting gut comfort. Mucilage’s gel-like texture forms a soothing coating that can help protect the gut lining from irritation more effectively than dry fibres.
  • Lubricates the digestive system to support regular, comfortable bowel movements. The hydrated gel facilitates the smooth movement of food and waste through the intestines, easing constipation and promoting regularity.
  • May help manage diarrhoea by forming a protective layer over the gut lining. The viscosity helps stabilise the gut environment and slow the passage of stool, which can ease mild diarrhoea.
  • Supports natural elimination of waste products from the gut. The gel-like mucilage binds to waste materials in the colon, helping to sweep them out effectively (in humans, this is often referred to as a ‘detox’ function).
  • Promotes feelings of fullness, which may support weight management. The hydrated gel expands in the stomach, naturally promoting satiety and reducing hunger without extra calories.
  • May help manage cholesterol levels and support heart health. The mucilage gel can bind bile acids, promoting their excretion and encouraging the body to use cholesterol to make new bile acids, thereby lowering circulating cholesterol.
  • Can assist in regulating blood sugar levels. The gel matrix slows the absorption of sugars in the gut, leading to steadier post-meal blood sugar levels compared to dry fibres.
  • Contributes to a balanced gut microbiome and supports immune function. The gel acts as a substrate for beneficial gut bacteria, encouraging their growth and promoting a healthy, resilient gut environment that supports immune health.

And of course, combining complementary seeds—such as flax and chia—can offer a more comprehensive range of mucilage benefits. Each seed contributes unique properties: flaxseed mucilage tends to form a softer gel that soothes the gut, while chia seed mucilage has a firmer, water-absorbing structure that supports hydration and bulk in the digestive system. By blending them, you can harness the strengths of each and provide your dog with a well-rounded approach to gut health.

Egg replacement

Chia mucilage is already used as a low-fat alternative for eggs in commercial baking, both to reduce calories and as a source of nutrients. In clinical studies in humans, chia mucilage was found to be a functional ingredient that can slow digestion and increase food functionality[4]. And psyllium mucilage is a prebiotic that can improve the viability of probiotic bacteria and carries natural antioxidant substances[5].

So, given the benefits of mucilage, I will certainly try it out in baking. I don’t think I’ll be giving my dog a chia pudding any time soon, but using moderate amounts of chia or flax mucilage in treats might be worth considering (though I probably won’t call them mucilage cookies…😟).

Watch out for mucilage as an ingredient in a recipe coming to you soon!

Considerations

While mucilage can offer several digestive and health benefits for dogs with a healthy gut, it’s a complex carbohydrate that may not be easily broken down by all dogs, particularly those with an underdeveloped or unbalanced gut microbiome.

It’s always a good idea to introduce mucilage gradually into your dog’s diet and to monitor their reaction to ensure it supports overall gut health without compromising nutrient intake.

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References:

[1] Michelle Monteiro Lira, Josemar Gonçalves de Oliveira Filho, Tainara Leal de Sousa, Nair Mota da Costa, Ailton Cesar Lemes, Sibele Santos Fernandes, Mariana Buranelo Egea, Selected plants producing mucilage: Overview, composition, and their potential as functional ingredients in the development of plant-based foods, Food Research International, Volume 169, 2023, 112822, ISSN 0963-9969, https://doi.org/10.1016/j.foodres.2023.112822.
[2] Liu Y., Liu Z., Zhu X., Hu X., Zhang H., Guo Q., Yada R.Y., Cui S.W. Seed Coat Mucilages: Structural, Functional/Bioactive Properties, and Genetic Information. Compr. Rev. Food Sci. Food Saf. 2021;20:2534–2559. doi: 10.1111/1541-4337.12742
[3] Hulya Cakmak, Hulya Ilyasoglu-Buyukkestelli, Ece Sogut, V. Hazal Ozyurt, Cansu Ekin Gumus-Bonacina, Sebnem Simsek, A review on recent advances of plant mucilages and their applications in food industry: Extraction, functional properties and health benefits, Food Hydrocolloids for Health, Volume 3, 2023, 100131, ISSN 2667-0259, https://doi.org/10.1016/j.fhfh.2023.100131. (https://www.sciencedirect.com/science/article/pii/S266702592300016X)
[4] H. Lazaro, L. Puente, M.C. Zúñiga, L.A. Muñoz Assessment of rheological and microstructural changes of soluble fiber from chia seeds during an in vitro micro-digestion LWT, 95 (2018), pp. 58-64, 10.1016/j.lwt.2018.04.052
[5] S.S. Arabshahi, M. Sedaghati Production of synbiotic Doogh enriched with Plantago psyllium mucilage
Journal of Food Science and Technology (2022), 10.1007/s13197-022-05401-8

Want to know more? These studies may be useful:

  • Dybka-Stępień K, Otlewska A, Góźdź P, Piotrowska M. The Renaissance of Plant Mucilage in Health Promotion and Industrial Applications: A Review. Nutrients. 2021 Sep 24;13(10):3354. doi: 10.3390/nu13103354. PMID: 34684354; PMCID: PMC8539170.

Important Considerations:

  • Always consult your veterinarian before making any significant dietary changes, particularly where there are pre-existing health conditions or dietary restrictions.
  • If you are feeding commercial food, check the label for ingredients before giving more. Excessive intake of any foods can have adverse effects.
  • Ensure (where possible) that you use high-quality, organic products specifically formulated for pets (or better still, human grade ingredients) to avoid any potential adverse effects.
  • Introduce new foods gradually to avoid adverse effects such as gastrointestinal upset or diarrhoea.
  • I provide nutritional information purely as a helpful guide. Nutritional information on ingredients is obtained from the US Department of Agriculture’s FoodData Central site (https://fdc.nal.usda.gov/index.html) and any nutritional information provided in recipes is based on an online calculator: calories and other information will vary based on brands, ingredients and other factors.
  • Check nutrient levels and recommendations for your dog’s weight, age and activity. For example this nutritional guideline produced by FEDIAF.
  • I am not a professional canine nutritionist but supporting research is cited.
  • The recipes shared were created by me and tested in my kitchen – and tasted and approved by our doggy friends!