Immune system, gut microbiome and pets: how do they relate?

All you pet owners out there, I’m sure you agree that adopting a pet is probably one of the best choices you ever made in your life. The unconditional love, the loyalty, the company they keep us and their stress-free qualities are something we should all look for in our every-day life. Their benefits, though, don’t stop there. They’re so good for our health in ways we don’t even imagine, with our immune system and gut microbiome gaining the most benefits out of this beautiful friendship and cohabitation. How is that so, you may wonder.

When it comes to animals in general and especially farm animals, researchers from the Ohio State University, in their study published in journal Frontiers in Immunology found that getting up close and… dirty with farm animals from an early age leads to a stronger immune system, as there is early exposure to a wide variety of environmental bacteria (1). Scientists studied fecal samples from the babies and found that bacteria and other microbes from rural Amish babies with exposure to farm animals were quite diverse and more beneficial than those found in urban babies’ intestines, which means that animal exposure can make a difference in gut microbiome in a beneficial way and can lead to a more robust development of the respiratory immune system. This certainly reverses our misconception that a sanitized environment is the best for us and our families.

Farm animals are one thing, but what about the most common and beloved pets, dogs and cats, that live in our apartments in a totally different environment than a farm? The news are still good, even as far as Covid-19 is concerned, as research published on May by Polish researches showed that there are often canine respiratory coronavisuses that occur among dogs, which brings their owners in contact with them. As scary as this may seem at first, scientists found that re-occurring contact with these coronaviruses stimulates human immune system to provide an effective response to SARS-COV-2 (2). This means that patients owning pets might have a mild course of the SARS-CoV-2 infection, something that was observed in Spain.

Pets in general, but especially dogs, can really make a difference in the indoor microbiome, raising the levels of 56 different classes of bacterial species –cats boost only 24 categories (3). And the sooner someone gets exposed to these micro-organisms the better, as another research showed that exposure during the first three months of life stimulates the immune system of a child. As a result kids that grow up with pets don’t become overly sensitive later in life.

Apart from gut microbiome and robust immune system, pets can help with lowering the risk of autoimmune diseases like allergies and asthma as well, which is no surprise, as gut health and allergies are connected. According to research published in PLoS One in 2018, it seems that cats and dogs protect against allergy development, reducing the prevalence of allergic disease in children aged 7–9 years in a dose-dependent fashion, suggesting a “mini-farm” effect, which may be the result of the diversity of microbes that pets bring in the house (4). Also, infants that live with dogs are less likely to have eczema (an allergy skin condition).

Don’t get me wrong, there are certainly some animal-borne microbes that are not beneficial and can harm us. Cats are carriers of toxoplasmosis, dogs can lick urine infected with leptospirosis and transmit the bacteria and there are some cases of salmonella bacteria on their skin and feces. What you need to do, though, to protect yourself is very simple: just wash your hands.

Having a pet is also a great psychological support for the owner, with those strongly attached to their furry friend being less likely to suffer from depression and anxiety. Pets are found provide benefits to those with mental health conditions and a fun company at the same time (5), elevating levels of serotonin and dopamine, neurotransmitters that make us feel good and calm.

What’s really impressive though is that clinical trial has shown that those who pet and talk to an animal present lower blood pressure than human conversation (6). Lower blood pressure, along with less stress are utterly beneficial for our heart health and the immune system, as cortisol and norepinephrine which are related to stress can have a negative effect.

If you have the time and the energy to make your family bigger by one short, fun and furry member, which definitely needs care, but gives it back in love, loyalty and health benefits, maybe it’s time to adopt!

More scientific-based articles will be coming in so stay tuned and browse through to see how you can support your immune system and gut microbiome in the most natural way.