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Probiotics vs. Prebiotics for Dogs

Your dog’s digestive tract is a mini-world full of biodiversity, with good bugs and not-so-good bugs constantly in a battle for balance. From puppyhood to the golden years, your dog’s gut microbiome has been uniquely influenced by the world around it – diet, environment, and experiences - and plays a huge role in their overall health.1 Approximately 70% of your dog’s immune system lives in their gut, which is one of the main reasons why it’s important for your dog’s microbiome to be balanced. When the microbiome is off balance, our dogs are more susceptible for immune dysfunction like diarrhea, allergies, and obesity.1,2 The immune system is impacted by the relationship between the intestinal microbiota and the dog’s mucosa (GI tract wall lining). This wall lining isn’t only a great physical barrier against infection, but it also responds to various stimuli, secreting mucus and stimulating immune responses (like proinflammatory molecules) to protect your dog’s body when necessary. Here’s where the microbiota come into play: after an acute inflammation episode, these good bacteria produce immune signals that bring the inflammation down back to its normal state, acting as GI tract immune system regulators.3 Not only do the microbiota work side-by-side with the immune system, but they’re key in digestion. That’s a lot of work for these tiny bacteria!

So how do we help balance the gut microbiome so that they can get their jobs done properly? With prebiotics and probiotics.

Prebiotics are the meal of choice for probiotics! Simply put, prebiotics are ‘eaten’ by probiotics in our intestines.4 They are carbohydrates or fibers that help regulate the digestive tract by both firming up loose stool or relieving constipation. But how can they do both? Fiber can actively moderate water content in the digestive tract, absorbing the excess water from loose stool or adding water in the case of constipation. Fiber is fermented near the end of the digestive tract, creating nutrients called short chain fatty acids (SCFA). SCFAs have antibacterial properties that help restore probiotic balance and relieve diarrhea.

Our prebiotic of choice is pumpkin because it’s so readily available when unforeseen issues arise! Pumpkin is surely a powerhouse food, rich in soluble fiber to help regulate bowel movements and are packed with both Vitamin A and Vitamin C, which are antioxidants. Just make sure that when you’re purchasing pumpkin puree, that it’s pure pumpkin and not pumpkin pie mix. Other sources of prebiotics include oats, beets, chicory root, flaxseed, sweet potatoes, and apples.5

Probiotics are the good bacteria that help maintain a balanced digestive tract. “To produce against pathogens, probiotics will produce a number of natural antibodies designed to reduce the populations of pathogenic bacteria...”6 These bacteria help reduce the population of the bad bacteria and increase the digestibility of micronutrients like calcium, zinc, and potassium. Another great benefit to probiotics is that they help to replenish the bacteria lost when antibiotics are taken. Antibiotics typically wipe out all of the bacteria (good and bad) in the gut and with the help of probiotics, the good are restored! Probiotics depend on your dog’s stomach acidity and diet, so what probiotics take root in your dog’s belly are different than your neighbors’ dogs. The bacteria classified as probiotics must be able to convert some of the sugars our dogs consume into organic acids that will be used by the GI tract to prevent growth of bad bacteria.      

Where do you find probiotics? The most common sources of probiotics are capsules or powder supplements as well as natural food sources, specifically fermented dairy products like fermented milk, buttermilk, soy milk, cottage cheese, sour cream, and more.7 

If you go the supplement route, it’s important you know what you’re looking at when reading the label. First, probiotic supplements are measured in colony forming units (CFU) – this is the number of sustainable cells. Most supplements contain between 1 to 10 billion CFU, though some go as high as 50 billion and beyond.8 Just because there are more CFU, does not mean that they will work better overall. Because probiotics are living organisms, during their life on the shelf or travels through your dog’s acidic digestive tract, many of the bacteria die and are no longer effective, hence the CFU in the billions. Even though some bacteria may not survive, others will and can take home in our dog’s digestive tract where our dogs can reap the benefits.

Probiotics is a broad term to describe the good bacteria that normally live inside our guts. There are many different groups, called families, and within these groups there are even specific types of bacteria, broken down into genus and species. The bacteria are grouped by how similar their characteristics are, physiologically, morphologically, metabolically, ecologically, and even molecularly. You’d be surprised how similar some of these bacteria are but are somehow still different genera and even further broken down into species by their differences.

Some common genera of probiotics include8:

  • Lactobacilli
  • Bifidobacterium
  • Saccharomyces
  • Streptococcus
  • Enterococcus
  • Escherichia
  • Bacillus

Each group of probiotics is unique and have been studied to understand their unique role and how they actually benefit the gut. Some bacteria produce antimicrobial substances like lactic acid, while others inducing mucus production so that pathogens can stick to the gut wall lining. While each has their own specific job, we are excited to share more about these specific probiotic groups soon, diving deeper into what exactly they do for our dogs: Firmicutes, Bacteroidetes,  Actinobacteria, Proteobacteria, Fusobacteria, and Euryarcheota.

Our dog’s microbiota are key players in their general health, impacting not only their gut health but also their immune health. Whether you decide to incorporate just probiotics into their diet, or both prebiotics and probiotics is up to you. Prebiotics (fiber) feed the probiotics (good bacteria) in order for Fido’s gut to fight off the bad bacteria as well as keep them regulated. As pet owners, we have become way too familiar with our dog’s poop. We recommend using the free DIG Labs Health Check app to conveniently and accurately capture, monitor, and share any stool changes with your veterinarian.




  1. Hullar MAJ, Lampe JW, Torok-Storb BJ, Harkey MA. The canine gut microbiome is associated with higher risk of gastric dilatation-volvulus and high risk genetic variants of the immune system. PloS one. 2018;13(6):e0197686-e0197686. doi:10.1371/journal.pone.0197686
  2. Grześkowiak Ł, Endo A, Beasley S, Salminen S. Microbiota and probiotics in canine and feline welfare. Anaerobe. 2015;34:14-23. doi:10.1016/j.anaerobe.2015.04.002
  3. Kainulainen, V., Tang, Y., Spillmann, T. et al.The canine isolate Lactobacillus acidophilus LAB20 adheres to intestinal epithelium and attenuates LPS-induced IL-8 secretion of enterocytes in vitro . BMC Microbiol 15, 4 (2015).
  1. Suvarnavibhaja, S. Dietary Management of Small Intestinal Disease. Hills Global Symposium. 2019.
  2. Mayfield-Davis, Melinda. Prebiotics for Dogs: What are They and What Do They Do? Vetericyn. January 2020.
  3. Adams, Casey. Probiotics – Protection Against Infection: Using Nature’s Tiny Warriors to Stem Infection and Fight Disease. April 2012.
  4. Harvard Medical School. The benefits of probiotics bacteria. Harvard Health Publishing. January 2014.
  5. NIH. Probiotics. June 2020.