Key takeaways:

-      Gut health is crucial to overall wellness

The gut does more than digest food! It influences mood, immunity, and skin health, making it essential to your pets’ well-being.

-      The gut is the immune system’s first line of defence

With 70% of your dog’s immune cells in the gut, a balanced microbiome is necessary to strengthen their natural defences, fight infections, and reduce inflammation.

-      Healthy gut = happy dog

The gut produces key neurotransmitters like serotonin, which play a role in reducing anxiety and promoting stable behaviour.

-      The gut and skin are closely connected

An imbalanced gut can contribute to inflammation and skin conditions, while a healthy microbiome supports clear skin and a shiny coat.

-      Prebiotics, probiotics, and postbiotics

Prebiotics nourish good bacteria, probiotics restore balance, and postbiotics provide beneficial compounds that support digestion, immunity, and overall health. These can be sourced from the land and the sea!

-      Tailored gut support at every age

Puppies, adults, and senior dogs require different gut support. Tailoring their diet and supplementation can enhance digestion, energy, and your pet's quality of life!

Here we go!

When it comes to our pets’ health, we often focus on the obvious—shiny coats, strong muscles, and a healthy amount of energy. But what if the key to unlocking your dog’s overall wellness lies deeper, in a place we rarely think about—the gut?

The gut, often referred to as the "second brain," plays a crucial role not only in digestion… but also in mood regulation, immune function, and even skin health. In fact, a healthy gut is the foundation of a healthy dog.

• Immunity: Approximately 70% of immune cells are found in the gut-associated lymphoid tissue (GALT), which acts as the first line of defence against pathogens(Gramenzi et al., 2024).

• Behaviour:The gut-brain axis links intestinal health to mood regulation. Short-chain fatty acids (SCFAs) produced by gut microbes play a role in neurotransmitter synthesis that influence mood and behaviour(Shah et al., 2024).

• Skin Health:The gut-skin axis demonstrates how a balanced microbiome reduces inflammatory conditions such as itching and licking associated with dermatitis(Tate et al., 2024).

But what exactly makes the gut so important, and how can we support it?

Let’s explore the world of gut health in dogs and make things a lot less complicated. 

Gut health under stress—what happens in challenging situations?

Imagine your pet facing a sudden change—maybe a new home, a trip to the vet, or a shift in diet. These everyday stressors don’t just affect mood. They also disrupt gut health. When stress hits, the balance of bacteria in the gut shifts, reducing beneficial microbes and allowing harmful ones to take over. This imbalance can upset digestion, causing diarrhea, constipation, and poor nutrient absorption.

As this imbalance worsens, the gut’s protective barrier weakens, allowing toxins and harmful microbes into the bloodstream—this is known as a leaky gut. The inflammation starts in the digestive system but quickly spreads throughout the body, affecting every organ system. Since the gut produces important neurotransmitters like serotonin and dopamine, this stress on the digestive system can influence the gut-brain axis, leaving dogs anxious, reactive, and even fatigued. At the same time, a weakened gut means a weaker immune system, leaving pets more vulnerable to infections and skin problems (gut-skin axis).

The good news? You can help restore balance.

By managing stress, providing a high-quality diet, and incorporating targeted gut support (like probiotics, prebiotics, and postbiotics), you can help strengthen your pet’s gut health. We’ve gone ahead and formulated our Bestie Biotics Thera-Chews to do exactly this, helping your dog overcome life’s challenges.

Keep scrolling to find out how the gut-brain and gut-skin axis are working!

                        

The gut-brain axis—how does the gut influence mood and anxiety?

Did you know your dog’s gut and brain are constantly communicating?

This connection, known as the gut-brain axis, is a complex network that links the central nervous system with the enteric nervous system in the gut. The gut can send signals to the brain through this network, influencing everything from mood to behaviour.

Research has shown that the gut microbiota—the community of bacteria living in the digestive tract—plays a key role in this communication. For example, certain strains of bacteria can produce neurotransmitters like serotonin, often called the "feel-good" hormone. Up to 90% of the body’s serotonin is produced in the gut, not the brain(Kiełbik & Witkowska-Piłaszewicz, 2024). This means that a healthy gut can contribute to a calmer, happier dog.

 

Key mechanisms by which the gut microbiota influences the central nervous system include neurotransmitter regulation, vagus nerve innervation, activation of the HPA axis, immune system modulation, and production of microbiota metabolites. (Kielbik 2024)

But how does this work in practice? Let’s take a closer look at the pathways involved:

1.    The vagus nerve:This long nerve runs from the brain to the gut, acting as a direct line of communication. Signals sent through the vagus nerve can influence everything from digestion to mood. For example, when the gut is inflamed, it can send distress signals to the brain, potentially leading to anxiety or stress(Kiełbik & Witkowska-Piłaszewicz, 2024).

2.    Neurotransmitters: As mentioned, the gut produces neurotransmitters like serotonin, which can influence mood and behaviour. An imbalance in gut bacteria can lead to a decrease in serotonin production, which directly affects the brain. Other neurotransmitters, like dopamine and GABA, are also produced in the gut and play a role in regulating the mood and behaviour of our pets(Sacoor et al., 2024).

3.    Immune system:Nearly 70% of your dog's immune cells are located in the gut, making it essential for disease resistance and overall health(Gramenzi et al., 2024). When the gut is healthy, it can help regulate inflammation, which has been linked to mood disorders in both humans and animals. However, chronic inflammation of the gut (like IBD) can lead to systemic inflammation as the gut barrier becomes leaky, allowing toxins from the gut to reach the brain, where they affect your pets’ mood and behaviour(Sacoor et al., 2024).

4.    Microbial metabolites:The gut microbiota produces various metabolites, such as SCFAs, which can influence brain function. For example, butyrate is a type of SCFA that is a major energy source for the cells (enterocytes) that form the intestinal barrier. The production of these SCFAs has been shown to have anti-inflammatory effects that protect against anxiety and stress(Parada Venegas et al., 2019).

Everything is connected! What happens in the gut can directly cause inflammation and stress.

Just as the gut influences the brain, it also plays a critical role in skin health. Let’s explore how the gut-skin connection works.

The gut-skin axis—how does gut health impact skin conditions?

While the gut-brain axis is a well-known connection, the gut-skin link is often overlooked. Just as the gut communicates with the brain, it also has a direct line to the skin. This connection, called the "gut-skin axis," explains why a healthy gut can lead to a healthier coat and skin for your pet.

The gut microbiota is crucial in regulating local and systemic inflammation, a key factor in many skin conditions. When the gut is out of balance—a condition known as dysbiosis—it can lead to systemic inflammation, which can manifest as skin issues like itching, redness, or even more severe conditions like dermatitis(Shah et al., 2024).

On the left, a healthy gut and skin maintain strong protective barriers, supported by a balanced microbiome and a well-regulated immune system. On the right, a dysbiotic state disrupts both systems. In the gut, an imbalance in bacteria, a weakened mucus layer, reduced IgA secretion, and increased permeability lead to inflammation. Similarly, the skin experiences microbial imbalances, reduced antimicrobial peptides, inflammation, and visible issues like rashes, thickening, or lesions. These disruptions are linked through immune system imbalance (such as Th2 skewing), with signals traveling between the gut and skin through the bloodstream and lymphatic system. (De Pessemier, B., et al 2021.)

Here’s how the gut-skin connection works:

1.    Inflammation regulation:A healthy gut helps regulate the immune system, preventing excessive inflammation that can lead to skin problems. When the gut is inflamed, it can lead to this “leaky gut” syndrome that we introduced earlier and trigger an immune response that affects the skin, leading to conditions like eczema, dermatitis, or allergic reactions. We’ve also discussed leaky gut syndrome in depthhere.

2.    Nutrient absorption: The gut is responsible for absorbing nutrients essential for skin health, such as omega-3 fatty acids, vitamins B and E, and zinc. If the gut isn’t functioning properly, these nutrients may not be absorbed efficiently, leading to dull coats, dry skin, or other skin issues(Leverett et al., 2022; Tate et al., 2024).

3.    Microbiome balance: The gut and skin both have their own microbiomes, and they are closely linked. An imbalance in the gut microbiome can lead to an imbalance in the skin microbiome, making your dog more susceptible to infections and skin conditions(De Pessemier et al., 2021).

4.    Toxin elimination: A healthy gut helps eliminate toxins from the body, reducing the burden on other excretory organs like the skin and kidneys. When the gut is compromised, toxins make their way into circulation where they can be excreted through the skin. This leads to skin irritation and inflammation(Salem et al., 2018).

This means that by supporting your pet’s gut health, you’re not just helping their digestion—you’re also promoting healthier skin and shinier coat through the gut-skin axis!

The role of dietary components—prebiotics, probiotics, postbiotics, soluble fibre, and fatty acids!

Now that we’ve explored how the gut influences both the brain and the skin, let’s dive into the dietary components that can support a healthy gut. These include all the “biotics” we’ve mentioned (prebiotics, probiotics, and postbiotics) but also go beyond that to include soluble fibres and fatty acids. Together, each of these dietary components plays a unique role in maintaining gut health.

1. Prebiotics = Fuel for good bacteria

Prebiotics are non-digestible fibres and other fibrous compounds that serve as food for beneficial gut bacteria, but they can also act directly on the gut microbiome. Common sources of prebiotics are plant-based soluble fibres from fruits, vegetables, and even algae. In a previousarticle, we discussed the importance of algae as a superfood (especially related to the gut-skin axis), but their importance as a prebiotic needs to be emphasised! 

How they work: Prebiotics pass through the digestive system undigested until they reach the colon, where gut bacteria ferment them. This fermentation process produces SCFAs, like butyrate, that the cells lining the digestive tract depend on to maintain a tight seal and prevent inflammation(Parada Venegas et al., 2019).

Prebiotics also help “good bacteria” thrive by allowing selective colonisation that helps them become established in the gut, blocking adhesion sites to prevent pathogen binding, increasing mucus production, and supporting the immune system through immunomodulation (Enam & Mansell, 2019).

Marine sulfated polysaccharides(MSPs) are particularly effective as a prebiotic! These are long carbohydrate chains, sourced from algae and other marine organisms, that are rich in sulphate groups which helps them resist digestion and reach the colon intact. Once there, the sulphate groups in MSPs play a key role in strengthening the gut’s mucus layer, blocking harmful bacteria from adhering to the intestinal lining, and promoting the growth of beneficial bacteria like Bifidobacterium and Lactobacillus(Ou et al., 2022). 

With feedback from veterinarians, we’ve added 200mg of marine sulphated polysaccharides to each one of our Biotics Thera-Chews to help support your pet’s gut microbiome! 

Schematic diagram illustrating mechanisms by which prebiotics influence the gut microbiota. The effect of prebiotics is shown below the dashed line. (1) Selective colonization of probiotic bacteria (bifidobacteria and lactobacilli) by competition with pathogenic strains for prebiotics. (2) Production of short-chain fatty acids (SCFA), acetate, propionate and butyrate, resulting in reduction of pH. (3) Exclusion of pathogen binding to epithelial cells. (4) Enhanced intestinal barrier function by increased mucus. (5) Modulation of immune response. (Enam 2019.)

2. Probiotics = The good bacteria

Probiotics are living microorganisms that support the gut microbiome and provide health benefits when consumed correctly. They help replenish and maintain the balance of good bacteria in the gut, which is essential for overall health.

How they work: Probiotics colonise the gut, competing for resources with harmful bacteria and preventing them from taking over. They have several roles, but the main ones include competitive exclusion, production of antimicrobial substances, enhanced epithelial barrier function, immunomodulation, and signalling back to the brain via the vagus nerve(Latif et al., 2023). Their presence alone is beneficial, but they also produce and secrete many molecules (postbiotics) that support a healthy gut microbiome.

Mechanism of action of probiotics. 1. Probiotics perform their function by competing with pathogens for nutrients and receptors for binding thereby making their survival and adherence to gut mucosa difficult. 2. Probiotics produce anti-microbial substances which inhibit pathogens growth. 3. Probiotics promote epithelial barrier function by enhancing mucus production and increasing the expression of tight junction proteins which prevents the translocation of pathogens from intestine into the blood. 4. Probiotics regulate immunity of the host by modulating maturation and function of dendritic cells subsequently increasing the activity of T cells which play important role in immune homeostasis. 5. Probiotics also regulate the production of neurotransmitters including serotonin, dopamine and gamma aminobutyric acid (GABA). (Latif 2023.)

3. Postbiotics = The byproducts of fermentation

Postbiotics are the metabolic byproducts of probiotics as they feed on the material inside the digestive tract. They can either be fermentation products, or molecules directly secreted by probiotics into the digestive tract. These include SCFAs, enzymes, and a long list of other bioactive compounds that benefit gut health.

How they work: Postbiotics contribute to gut health by supporting the intestinal barrier, reducing inflammation, and modulating the immune response(Mosca et al., 2022). They also play a crucial role in neurotransmitter production, influencing the gut-brain axis. A variety of postbiotic compounds—including proteins, exopolysaccharides, SCFAs, lactic acid, and essential neurotransmitters like dopamine, serotonin, and histamines—are believed to promote a balanced microbiota and enhance your pet’s overall well-being(Salminen et al., 2021)!

Postbiotic mechanism of action. Postbiotics could act in many ways, four of which are illustrated here. Postbiotics could enhance barrier function, through the stimulation of tight junctions, or by stimulating mucous production. Postbiotics could also act through changes in the microbiome and could modulate the immune response. (Mosca 2022)

4.    Soluble fibre = Aids digestion and absorption

Soluble fibre is a type of dietary fibre that dissolves in water, forming a gel-like substance. It plays a key role in digestion by modulating gut function, promoting satiety, and serving as an energy source for gut bacteria. On the other hand, insoluble fibres aren’t digestible and mainly function to speed up the rate at which food passes through the digestive tract.

How they work:Soluble fibre is fermented by gut bacteria to produce SCFAs, which help nourish gut cells, support the gut barrier, and reduce inflammation. This fermentation process also helps regulate digestion by thickening the food in the gut and slowing it down, allowing for better nutrient absorption. The degree of fermentability varies by fibre type, with rapidly fermentable fibres (like fruit pectins and gums) being the primary sources of SCFAs. Common sources of soluble fibre include oats, carrots, legumes, apples, and flaxseeds(Moreno et al., 2022).

Solubility and fermentability of various dietary sources of fibre. (Moreno 2022)

5.    Fatty acids = Essential for gut integrity and function

Fatty acids are essential for gut health and come in short- and long-chain forms. SCFAs can be naturally produced by gut bacteria as they ferment dietary fibre. Long-chain fatty acids, such as omega-3s (EPA and DHA), are found in foods like fatty fish and algae.

How they work: SCFAs help nourish gut cells, support the gut barrier, and reduce inflammation. Long-chain omega-3s, like EPA and DHA, play a key role in reducing inflammation in the gut and supporting overall digestive health. These long-chain fatty acids can be taken apart and recycled to produce SCFAs, enhancing gut function even further(Dominguez et al., 2021). In addition, SCFAs have a key role in helping regulate the gut-brain axis(Zinkow et al., 2024).

Interaction Between the gut and the brain through the gut–brain axis. HPA axis, hypothalamic-pituitary-adrenal axis; ENS, enteric nervous system; SCFA, short-chain fatty acids. (Zinkow 2024)

This might initially seem a little overwhelming, but we’ve tried to make it foolproof!

At Bestie, we’ve formulated ourbalancing supplements,therapeutic chews, andbroths based on research and advice from veterinarians to deliver the precise nutrients your pet needs in the right amounts. This way, our pets eat well without any guesswork on your part. 

Gut health is a lifelong journey

Gut health isn’t one-size-fits-all—it evolves throughout a dog’s life. From playful puppies to aging seniors, each stage requires tailored care. Supporting gut health ensures a happier, healthier life for your furry friend.

Let’s take a closer look at each stage.

Puppies and kittens: Building the foundation

Your puppy’s gut undergoes major changes in the first months of life.

Early on, they rely on their mother’s milk, which provides natural prebiotics to help establish a balanced gut microbiome and strengthen immunity. However, the transition to solid food can be challenging. Their immature digestive system needs time to adapt to new nutrients, making any sudden dietary change a risk for digestive upset, imbalanced gut bacteria, and increased vulnerability to illness.

It's crucial to ensure this transition period goes smoothly since this is the moment the gut microbiome becomes established.

To ease this transition, incorporating soluble fibres and probiotics is essential(Gramenzi et al., 2024). These support digestion, promote a healthy microbiome, and help reduce the risk of future gut-related issues. A slow, gradual diet shift can make all the difference in maintaining digestive balance.

Need help choosing the right supplements?Reach out to us or your vet for guidance toward puppy-friendly probiotics and prebiotics. 

Adulthood: Maintenance and optimisation

As our pets become adults, gut health shifts from development to maintenance, but they’re still vulnerable to disturbances. Factors like illness, dietary changes, and environmental stressors can upset the gut balance, leading to inefficient digestion and suppression of the immune system. A diet rich in fibre (prebiotics), omega-3s, and high-quality proteins helps provide the resources to maintain stability and support stressful periods for our pets.

Ideally, our pets should be receiving a combination of prebiotics, probiotics, and postbiotics so they can work together to enhance nutrient absorption, reduce inflammation, and support gut stability(Shah et al., 2024). During periods of stress, illness, or dietary transitions, these supplements can be especially beneficial in restoring balance and supporting immune defences(Bhosle et al., 2024).

Senior pets: Supporting aging

As our pets age, their gut microbiome naturally changes, leading to reduced nutrient absorption and a higher risk of inflammation. This shift, combined with age-related immune decline, makes our senior pets more susceptible to digestive disturbances and chronic conditions. A diet with easy-to-digest proteins, soluble fibres, and postbiotics can help counteract these effects(Rindels & Loman, 2024).

Remember that postbiotics aren’t living bacteria, but instead beneficial compounds produced by bacterial fermentation. They support gut integrity, promote efficient digestion, and provide anti-inflammatory benefits. We can utilise postbiotics to give the gut microbiome specific ingredients without relying on live probiotics to produce them. This doesn’t mean we should skip probiotics completely, since they have many more benefits besides producing postbiotics, but their use in combination is a reliable option for older dogs! Especially those with underlying health concerns.

The path forward

The science is clear—gut health isn’t just a trend, but the cornerstone of your pet’s health.

By understanding the gut’s function beyond digestion, we can finally begin supporting the gut-brain and gut-skin axes by being proactive. A healthy gut doesn’t just happen by chance… no.

It needs to be intentional!

From reducing anxiety to improving skin and immunity, the benefits of a well-supported gut are undeniable and make it a worthy investment for your pet’s future. That’s exactly why we’re here to provide a tailored approach that meets your dog’s unique needs naturally (and effectively).

Now, pet parents can ensure their pups lead healthier lives!

Writer: Ash Sadri

Ash is a Canadian final year veterinary student studying in Croatia. Before deciding to become a vet, Ash completed his Masters degree at the University Of Western Ontario where he specialised in cancer stem cells research. Since then, he’s been working as a veterinary technician and has special interests in animal nutrition and surgical procedures!

 

Works Cited

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