Are pets “probiotics” for humans? – News

Most people know that pets hold a special place in the hearts of many humans, providing a source of comfort and enhancing mental well-being. Few people realize that pets can improve the composition of our gut microbiota, providing a variety of unique health benefits to their owners and perhaps even veterinarians. maybe.

This is a phenomenon that scientists are only beginning to fully understand, and suggests that the types of organisms that live in our guts and other parts of our bodies can be greatly influenced by who we share our lives with. , has been proven by numerous studies.

Inside each of us is a community of trillions of microorganisms, including bacteria, viruses, archaea, and fungi that make up what is known as the microbiome.

The idea that regular contact with dogs, cats, and other animals enriches communities continues to grow as cutting-edge DNA sequencing technology allows scientists to map the microbiome and determine its impact on our health. As we begin to understand more deeply, we are gaining traction.

The likelihood of developing diseases such as asthma, obesity, inflammatory bowel disease, diabetes, cardiovascular disease, arthritis, cancer, and depression has been shown to be influenced to varying degrees by the composition of the microbiome. There is still much to learn.

“With all its pros and cons, the microbiome, especially the gut microbiome, influences almost every aspect of human and animal health,” said Dr. Laurel Redding, assistant professor of epidemiology at the University of Pennsylvania School of Veterinary Medicine. .

Redding has spent years researching the benefits that pets have on the human microbiome. Her latest research, currently in the recruitment phase, is investigating how pet ownership can increase resistance to antibiotic therapy in older adults.

Work is also underway to identify which diseases specifically may be suppressed by contact with non-human animals. Dr. Redding points out that previous studies have shown conditions such as asthma. atopic (proneness to develop allergic diseases), obesity, and certain bacterial infections may be prevented by interspecies exchange of microorganisms.

when two clouds merge

The composition of an individual's microbiome varies from person to person, but is greatly influenced by the composition of the mother's microbiome. However, for better or for worse, new residents emerge in our lives. As a result, an individual's microbiome may more closely resemble the microbiome of a friend or lover than the microbiome of a stranger.

Last year, the publication of a groundbreaking Italian study based on more than 9,700 human stool and saliva samples collected from people on five continents heightened the conversation about the extent of these links. Participants from the same household shared a “significant” number of bacterial strains in their intestines and mouths, 12% and 32%, respectively, the study found. The report also concluded that cohabitation affected sharing “more than age or genetics.”

“Germany-obsessed people may not understand this, but we're all like little clouds of germs, and every time we come in contact with a surface, another animal, or a human, we interact with other clouds of germs. ,” Dr. Celeste said. Mr. Alabando is a veterinarian and microbiologist at the University of California, San Diego. “For the most part, there is very little transfer, but the longer the contact and the more contact there is, the more things are likely to come and go.”

Although separate microbiomes exist in many parts of (or on) an animal's body, most research has focused on studying the gut microbiome, in part because it is so rich in the life forms that live there. are attracted to.

“The gut microbiome is like the Amazon rainforest,” Alaband says. “It's the most diverse and has the most going on. It interacts with our diet, our immune system, and our metabolism.”

The description of the stirring of Araband's clouds is more descriptive than literal. Transmission of microorganisms from animals to humans occurs through simple pathways such as skin-to-fur contact altering the skin microbiome. For example, the gastrointestinal tract is affected when a pet licks its owner's face or when an owner pats the pet before eating a sandwich or fries. There is also exposure to things your pet touches, such as clothing, bedding, leashes, and bowls. “Some of these taxa can also be found on surfaces that are less commonly touched, such as walls and television screens,” Alaband said.

Of course, bad bugs are also transferred to your microbiome. For example, pet owners risk exposure to unwanted guests such as: campylobacter and Salmonellasome of them may have developed resistance to drugs designed to kill them.

“It's really unclear at this point where the sweet spot is to avoid the bad bugs and catch the good bugs,” Redding said.

Benefits of pets may become apparent during childhood

Although it is unclear to what extent the human microbiome changes due to exposure to microorganisms from other animals, there are certain beneficial microorganisms that are more common in pets than in humans.For example, compared to humans, dogs tend to host more lactic acid bacteriawidely considered in the human medical community as probiotics, are bacteria, microorganisms that are introduced into the body for apparent benefits. lactic acid bacteria Redding says it has anti-inflammatory properties that may help fight diseases related to immune responses, such as asthma, atopic dermatitis and obesity.

“There are studies showing that children who grew up on farms surrounded by animals, or people who grew up in households with furry pets, are less likely to develop such conditions, and microbial Symptoms are thought to be regulated by shared plexuses,” Professor Redding said. “It hasn't been definitively proven, but it's certainly a working hypothesis.”

The situation is complicated. Especially since various studies have shown that pet ownership impacts: increase Risk of childhood asthma. Timing appears to be a key factor. The earlier a child is exposed to animals, the more likely they are to benefit. “The first 1,000 days of life is when your microbiome is all kinds of fluid and trying to set itself up for the rest of your life,” Alaband explained.

The lower incidence of asthma in children raised on farms may be related to the so-called hygiene hypothesis, the idea that exposure to insects is good because it helps set up the body's defenses. There is, she claims. “In the city, we are constantly cleaning,” Alaband said. “We just don't interact with the external environment as much.”

One of several studies linking pet ownership to lower disease risk in children was conducted in Sweden. The report, published in December 2018, found that in a cohort of more than 1,200 children, 49% of children who reported not owning a pet within the first year of life had asthma, hay fever, The researchers found that children who didn't own pets had none of the symptoms of allergies, such as eczema. The children reportedly lived with five or more pets.

“The prevalence of allergic diseases in children aged 7 to 9 years decreases in a dose-dependent manner depending on the number of household pets that live with the child during the first year of life. This suggests a “mini-farm” effect where people live together. “Dogs prevent the development of allergies,” the paper concludes.

Further research is expected

The science is less conclusive about the tendency for beneficial microbes to be exchanged with pets over the course of their lives, but it's still promising. Other studies show that interactions with pets are common, such as a study published in 2013 that found that dog ownership has a significant impact on the skin microbiome of adults.However, a study published in 2020 based on analysis of stool samples from 332 participants in Wisconsin found that only four types of microorganisms were more abundant in participants with pets; Seven types of microorganisms were found to be more abundant without it pet. “Future research is needed to further elucidate the relationship between the gut microbiome and pets,” the researchers concluded.

At the University of Pennsylvania, Redding is trying to find out more. Her latest effort is tracking people taking antibiotics for dental implants to see if owning a pet can help the gut microbiome recover faster from the drugs. . Taking antibiotics can have a variety of adverse effects, ranging from mild diarrhea to potentially life-threatening infections. clostridioides difficile (commonly known) temperature difference) Older people are especially at risk.

The veterinarian led a previous study published in 2020 that found that owning a pet lowers the incidence of relapse. temperature difference Infection to humans. She hypothesizes that a richer microbiome may help its inhabitants overcome opportunistic pathogens such as: temperature difference For real estate in the gut.

Alaband also uses methicillin resistance to allude to this obvious competitive factor. Staphylococcus aureus (MSRA) is a bacterium that causes difficult-to-treat infections in humans.

Dogs host a relatively large amount of related bacteria, she said. intermediate staphylococcus, compared to humans. “They are both StaphylococcusAnd both compete for the same resources,” she said. Staphylococcus Can keep human things around Staphylococcus aureus They are kept in check because they are constantly fighting for the same space within the microbiome. ”

Additionally, a study published in late 2022 based on data collected by a project called American Gut, a non-profit research initiative led by scientists at the University of California, San Diego, found that dog breeding has increased the Bifidobacteriaceae and Ruminococcaceae in people over 65 years of age were found to be associated with an increased amount of clearly beneficial bacteria.

The American Gut project was implemented in 2012, followed by the British Gut project in 2014. These “citizen science” initiatives, which involved volunteers submitting skin, saliva, and stool samples for analysis, formed the basis of the currently active Microsetta initiative.

Alaband, who worked closely with the American Gut project, said researchers collected only a small number of pet samples at the time. She expects more samples from non-human animals to be submitted for further research.

As our knowledge increases, she thinks we may see more exchanges of beneficial microbes between humans and non-human animals. She says: 'Dog owners' homes are enriched with certain bacteria that are known to produce antioxidants, anti-inflammatory and anti-cancer type molecules. [and] It’s a cholesterol-lowering and glucose-lowering metabolite,” she said.

Veterinarian-style microbiome

What about the idea that veterinarians and veterinary technicians may have their own type of microbiome because they frequently work with a wide variety of animals?

“I'm sure of that!” Redding said with a laugh. “But the short answer is that it hasn't been investigated.”

At the same time, Professor Redding points out that a study published in 2022 and conducted in the Netherlands found that veterinarians are also using similar treatments. temperature difference The risk of exposure is similar to the general population, albeit higher.

Alavand is optimistic that veterinarians are clearly enriching the microbiome in patients' favor.

“I haven't seen any actual studies that have looked at that,” she said. “But I'm sure it is.”