Comparison of Probiotic Supplements for Dogs and Cats

What are probiotics?

The bacteria in our body outnumber that of our body’s cells by a factor of ~10. They reside mostly in the gut and a vast majority of them are either harmless or the functions not yet well understood. Although humans and other animals also harbor some harmful ones in relatively low numbers, there are some that are quite beneficial and linked to numerous health benefits, including improved digestion, weight loss, enhanced immune function, healthier skin, and a reduced risk of many diseases.  

Probiotics are basically these beneficial viable, living microbial cells that are usually obtained from external sources for improving the gut environment and health of humans or that of other animals, including your furry friends. In other words, they are the type of friendly bacteria that provide health benefits when eaten. They are often taken as supplements from external sources and supposed to colonize the gut and maintain long term digestive health and environment for optimal overall health.

While there are some yeast and fungi that are also used as probiotics, this blog is about the two broad categories of bacterial species. 

Why pets need probiotics from external sources?

Pet foods and treats nowadays are highly processed, primarily through extrusion. They go through extremes of temperature and other environmental and industrial factors that affect the quality of any pet food drastically. Any beneficial bacteria that the food may have had naturally is destroyed in the process. As a result, such a food or treat is not conducive for maintaining optimum digestive health. Considering almost 80% of pet diseases are related to digestion and gut, it is vital that we help our four- legged friends maintain their intestinal microbiota at an optimum level.

 What's the difference among probiotic species? 

Two broad categories of bacteria are used as probiotics. They are a.) spore forming, such as the genus of Bacillus, and b.) vegetative, which are non-spore forming and come mostly from the genera of Lactobacillus, Bifidobacterium, and Enterococcus. Which ones are used makes a huge difference in the efficacy of any of these products.

Spore forming bacteria: 

Spores are meant for survival in stressful conditions and therefore, spore forming ones are extremely durable and can be very difficult to destroy even under extreme temperatures. They can survive drought, extreme temperatures, and low pH, including that of the upper digestive tract (or stomach).  Once favorable conditions return, like when they reach the lower digestive tract, the protective proteins dissolve the spore coating and the bacteria can then resume their normal functions.

Compared to the widely used vegetative bacteria of Lactobacillus, Enterococcus or Bifidobacterium genera, bacterial spores of Bacillus genus offer the advantage of a higher survival rate during the acidic stomach passage and better stability during the processing and storage of the food product. Furthermore, studies have shown that spore itself exerts an immunostimulatory effect which serves to exclude the colonization of the gut by harmful pathogens. This offers an added benefit and makes them a much better fit for fortification as probiotics in the pet food products.

Non-spore forming or vegetative bacteria:

On the other hand, non-spore forming ones used in probiotics are common vegetative bacteria. They are much more susceptible to environmental stresses like heat, air, and desiccation as well as manufacturing conditions, such as extrusion, heating, drying, or even changing storage and environmental conditions. More importantly, their cells tend to be sensitive to the extremes of acid and alkaline conditions, as found in the stomach and small bowel. Studies have shown that most are quickly killed off in the harsh, acidic environment of the stomach and therefore, your pets may not be able to get the full benefit no matter how many different types or numbers they may be present in a product.

Market scenario: 

Non-spore forming or vegetative bacteria are much more commonly used in probiotics than their spore forming counterparts, primarily because of cost. Probably >90% of probiotics sold in the pet food industry are multi-strain, Lactobacillus, Bifidobacterium or Enterococcus based formulas. There are some that contain one species of Bacillus, while a few also contain a mixture of one species of Bacillus and several other of vegetative type. Rare are those that have two or more species from Bacillus genus and they are the best you can offer your dogs and cats as long as they also contain some other critical components (see below).

So, how to separate the chaff from the real, good? 

It's actually quite simple if you just pay a little attention to the label. Only spore forming strains begin with the word "Bacillus." If a strain listed on a label begins with anything else, it is one of the non-spore forming, more fragile bacteria. Most likely they are Lactobacillus or Bifidobacterium or Enterococcus or their blends.

What other components would complement the probiotics to make a better product?

1. Prebiotics

Just like we and our pets need food, bacteria also need their food to draw the essential nutrients for their own health and well-being. That food usually comes in the form of various types of fibers, mostly insoluble ones, and often is termed as prebiotics. Typically, high-fiber foods, such as whole grains, fruits and veggies, act as food for such beneficial microflora. Inulin from Jerusalem artichoke or chicory root is probably the most commonly used prebiotics in any probiotic product. Fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) are other prebiotic substances. Relative to inulin, which is slightly longer and has more cross-links in its structure, FOS and GOS are shorter chain molecules and are linear in their molecular structure.

2. Digestive enzymes

Since the primary objective of probiotic supplementation is to improve digestive health and maintain a healthy gut environment, adding enzymes that can enhance the digestion and metabolism of other nutrients, such as protein, fats, and more complex carbohydrates makes perfect sense. Those enzymes are known as proteinase, lipase, and amylase with some specific names depending on the origin of an enzyme, particularly in the case of proteinases. Similarly, cellulase, hemicellulose, pectinase, etc. are enzymes responsible for breaking down carbohydrates of plant origin.

3. Herbs

There are many herbs, be they American, Ayurvedic, native American, and other exotic ones, that are of tremendous benefit for enhancing digestive health. Their inclusion certainly enhances the overall quality of the product.

 4. Antioxidants

Though not a component of most conventional probiotic products, antioxidants add another dimension to them. While vitamins such as A, C, and E and many polyphenolic compounds found in fruits, Ayurvedic herbs (such as turmeric, aloe vera, etc.), vegetables, and whole grains have high antioxidant capacity, astaxanthin is probably one of the most powerful ones available commercially. Krill powder is probably the best source of astaxanthin naturally.

What's in Probiotic Pro from Science4Pets (www.science4pets.com)?

Unlike the industry common vegetative types that are used in a vast majority of the probiotic products, Science4Pets uses the two most effective spore forming species, Bacillus coagulans and Bacillus subtilis with only a tiny fraction of the total count from vegetative group. Many of our competitors even try to confuse regular customers by providing the number of species from Lactobacillus, Enterococcus, and Bifidobacterium genera, whereas others mention the relatively high cfu count of the same species as if that makes up for the defective product.

Additionally, Probiotic Pro from Science4Pets (www.science4pets.com) contains all the other vital components, such as prebiotics, digestive enzymes, herbs, and astaxanthin from krill as the antioxidant to make it the best product in the market for enhancing the digestive health of your dog or cat.

Below is an extensive table that provides a clear comparison of 23 different probiotic and similar digestive health products manufactured for dogs and cats as supplemental powders. They include many name brand (or otherwise) companies. Although this is not an exhaustive list, it covers a wide range of companies, large and small. The price and other details are reflective of the time when this article was written and may vary based on when a potential customer checks and when individual companies change their business and marketing approach.

For further info on probiotics, please check these scientific peer reviewed journal publications:

Casula and Cutting (2002): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC127533/pdf/1491.pdf

Bader et al (2012). https://www.wageningenacademic.com/doi/10.3920/BM2011.0039

Hong et al. (2005): https://academic.oup.com/femsre/article/29/4/813/493366