It’s time to start trusting your gut — at least when it comes to staying young and living longer.

Research has shown that the gut microbiomes of healthy older people — including those in their 90s over age 100 — often resemble those of people who are decades younger.

But your gut microbiome isn’t just a matter of chance: Fine-tuning it can turn back time, leading to better metabolism, sleep, thinking and immunity, according to microbiome expert Colleen Cutcliffe, Ph.D.

“Even though our metabolism, muscle strength, brain function and immune system are really different parts of the body, they’re all tied together through the gut,” said Cutcliffe, CEO of Pendulum Therapeutics, told The Post. “So, when you have a healthy gut, all these other systems are fueled.”

Things we associate with aging — including cognitive issues, slower metabolism and longer recovery periods following illness — all tend to coincide with our gut deteriorating as we get older.

Cutcliffe equates being in your “prime” to the time when your gut microbiome is at its peak, or when it has its greatest number of functions working and is the most resilient.

“We all remember the days when we could eat or drink whatever we wanted and it was fine,” she said. “Over time, we begin to lose the specific strains that give us that resilience.”

Her simple, science-backed steps to cultivating a younger gut at any age are intended to replenish those things we’ve “lost over time.”

Feed your gut to good health

Eating foods high in fiber or polyphenols — including leafy greens, vegetables, fruits and berries — can do major damage control.

Lentils are super high in fiber, while green teas and spices, especially cinnamon, contain plenty of polyphenols, all of which are going to feed those lost strains.

Reducing stress and moving around daily can also lead to big bacterial improvements, which are all essential for longevity.

Don’t overdo it on antibiotics

Antibiotics are also anti-gut health, says Cutcliffe, since they’re designed to wipe out all bacteria — both good and bad

“They completely destroy your gut,” she argues. “If you’re on an antibiotic and you don’t feel so good or aren’t really recovered, it’s not in your head — it does mess with you.”

That isn’t to say don’t take medication prescribed by your doctor, but taking antibiotics too often can cause problems — not to mention, lead to drug-resistance diseases.

How can you tell your gut microbiome is… off?

When it comes to a healthy microbiome, the proof is mostly in the — uh, pudding.

Cutcliffe explained that poop is your number one diagnostic marker for what’s happening in your gut and overall health. The consistency is key — for example, too hard can mean you’ve got low microbial diversity, and too watery might mean an overgrowth of bacteria. Diarrhea and constipation are both usually signs that it’s time to get your gut checked out.

The benefits of good bacteria

Scientists believe a “youthful microbiome” may help protect against the chronic inflammation and disease risks that come with aging.

“Your gut gets depleted as we age, which can lead to the worsening of disease,” said Cutcliffe. “We experience a decline in our health where we can’t remember things as well, or we get more tired, but we don’t have to live like that.

“Improved gut health translates to improvements across the board in ways you wouldn’t even expect, including skin health.”

Many ailments can in fact be traced back to how good your gut is.

If you are dealing with multiple issues at once — bad skin, sleep issues, getting sick often — a healthy gut is mostly likely the cause as it’s at the core of how your body is signaling to the brain, as well as your metabolism and immune system.

“We have dermatologists using this strain to help people with adult acne and atopic dermatosis.”

Mounting evidence continues to suggest that microbiomes might play a role in the prevention of the onset of cancer, and it has been shown that chemotherapy is more effective for those who have more strains in certain microbiomes.

This can result in less required treatment time.

The staying power’s in the strains

Healthy older people tend to have diverse bacteria in their guts — and are also more likely to have certain strains inside them. Among them are Christensenellaceae, which is associated with healthy BMI, and Bifidobacterium, which is linked to immunity and good digestion.

They also often have higher levels of Akkermansia muciniphila, which Cucliffe says is “one of the strains that’s emerged as a keystone trait for your gut.”

“Losing this strain is associated with a less productive metabolism, as well as a worse immune system, worse brain function, and worse inflammation, so giving your body back a strain like this can change everything,” she said.

Keeping the Akkermansia strain high is also crucial to keeping the weight off. That’s because it secretes the protein known for stimulating the body’s natural GLP-1, which is what weight loss drugs such as Ozempic and Wegovy are meant to mimic.

Cucliffe’s company Pendulum, which helps to develop microbiome-targeted products, has also created its own version to help women battling diabetes or pre-diabetes while going through menopause.

“Our novel strain, live Akkermansia muciniphila, helps your body produce its own GLP-1 naturally, and we are the first and only probiotic clinically tested to nutritionally help lower glucose spikes and A1C in patients with type 2 diabetes,” she said.