Called the microbiome, it consists of the millions of organisms that live in us and on us, said Elizabeth Corwin, vice dean of strategic and innovative research at the Columbia University School of Nursing. And a healthy microbiome is a crucial part of good health.
It influences the immune system and helps synthesize important vitamins in our gut, Corwin added. Those organisms also offer protection, can help heal wounds, kill off bad pathogens and help certain medications work better, said Sheena Cruickshank, a professor in the division of infection, immunity and respiratory medicine at the University of Manchester in the United Kingdom.
Caring for your microbiome can help with many conditions, including allergies, asthma and autoimmune diseases, Cruickshank said.
“What we really mean by a good microbiome is a diverse microbiome,” Cruickshank said. “Lots of disease tends to be associated with a lack of variety.”
She and Corwin shared easy ways to get more microbial variety in your life.
What about a dog?
Looking for an excuse to adopt a dog? Here it is.
Studies show that dogs share their microbiome with the household, Corwin said. Growing up with a dog has been shown to reduce the chances of developing asthma and allergies, Cruickshank said.
And caring for a pet is a pleasant way to exchange bacteria, she added. Just having animals around can help.
“We also have a microbiome in our buildings and in the air around us,” Cruickshank said. “It’s suggested that rural microbiomes have a little bit more variety, and they may be better for our lung health.”
Sorry cat people, but Corwin said that dogs appear to be the most helpful pet to the microbiome.
Lower your stress
One important microbiome health factor is how leaky, or permeable, your gut is.
Everyone’s gut is permeable to some degree, but some people’s guts are leakier than others, Corwin said. If your gut leaks the healthy and helpful microorganisms, that is fine, she added. But if you leak more virulent microorganisms, immune cells waiting outside will activate, which can cause inflammation.
So how does your stress come into play?
“High cortisol, which is one of our stress hormones, can actually increase the leakiness of your gut,” Corwin said. “If you’re living with high stress, your gut might be leakier.”
Vary your diet
A high-fiber, varied diet is important to a healthy microbiome, experts said.
Microbiota love foods with lots of fiber, such as fruits and vegetables, Corwin said. The fiber is not well digested in the stomach and tends to get broken down more by the microorganisms, and it moves through the gut, she added.
Fermented foods can be helpful, because they often give you live bacteria, Cruickshank said. But, although some studies have shown effectiveness, it is tricky to know for sure if you are going to get helpful bacteria from the fermented foods you eat because the batches can vary so much.
Cruickshank said she worries about the microbiomes of people who limit their food, either due to restrictive dieting or because they rely on high-fat but convenient foods.
“If you’ve got a varied diet with lots of fruits and vegetables, that gives it lots of different things to chomp on and enjoy,” Cruickshank said. “The simplest thing we can do is have a good, balanced diet.”
What about probiotics?
Perhaps. Probiotics are often the first thing we think of when we talk about gut health, but the evidence on how effective they are is mixed, Cruickshank said.
They are often recommended after an antibiotic to replenish the good bacteria that can be killed alongside the bad with medication.