Being regular is good for you, a new study shows.

Predictable bowel movements could be tied to your long-term health, allowing your body to absorb essential nutrients without producing harmful organ-damaging toxins, researchers found.

The “Goldilocks zone” of bowel movement frequency, once or twice a day, is associated with better health, results show.

That gives gut microbes enough time to digest dietary fiber, which they ferment into beneficial short-chain fatty acids, explained lead researcher Johannes Johnson-Martinez, a doctoral student with the Institute for Systems Biology in Seattle.

“After that, the ecosystem switches to fermentation of proteins, which produces several toxins that can make their way into the bloodstream,” Johnson-Martinez explained in an institute news release.

For the study, researchers analyzed medical and lifestyle data for more than 1,400 healthy adults, according to the study published July 16 in the journal Cell Reports Medicine.

These folks were divided into four groups based on bowel movement frequency — constipation, low-normal, high-normal and diarrhea. The constipated moved their bowels once or twice a week, low-normal three to six times a week, and high-normal one to three times a day.

People with constipation and diarrhea tend to have higher levels of bacteria associated with toxic protein fermentation, results showed.

The toxins produced by protein fermentation can cause organ damage, the researchers added.

For example, a protein fermentation byproduct called indoxyl-sulfate is significantly associated with reduced kidney function, results show. Blood levels of that byproduct and another toxin called p-cresol-sulfate were elevated in people with constipation.

Meanwhile, other toxins associated with liver damage were higher in people with diarrhea.

“Chronic constipation has been associated with neurodegenerative disorders and with chronic kidney disease progression in patients with active disease,” said researcher Sean Gibbons, an associate professor with the Institute for Systems Biology.

“However, it has been unclear whether or not bowel movement abnormalities are early drivers of chronic disease and organ damage, or whether these retrospective associations in sick patients are merely a coincidence,” Gibbons added. “Here, in a generally healthy population, we show that constipation, in particular, is associated with blood levels of microbially derived toxins known to cause organ damage, prior to any disease diagnosis.”

Not surprisingly, people tend to be in the Goldilocks zone if they eat a fiber-rich diet, drink lots of water, and have regular exercise, researchers said.

Younger people, women and those with a lower BMI tend to have less frequent bowel movements, results show.

Mental health also can affect a person’s bowel movements, results show.

“Overall, this study shows how bowel movement frequency can influence all body systems, and how aberrant bowel movement frequency may be an important risk factor in the development of chronic diseases,” Gibbons said. “These insights could inform strategies for managing bowel movement frequency, even in healthy populations, to optimize health and wellness.”