Taking a probiotic supplement can reduce cognitive decline and can help when you’re stressed

• The health of your brain is closely related to the health of your gut.
• Research has shown that taking probiotics can help prevent cognitive decline in the elderly.
• It could also help younger adults perform better when under stress.

Scientists already know that probiotic supplements show promise in treating gut health conditions such as IBS and gastrointestinal upset after taking antibiotics.

Now scientists think they could also slow cognitive decline as we age, says Jessica Eastwood, a researcher in the psychology of eating in the department of psychology and clinical language sciences at the University of Reading in England.

In younger people, Eastwood told Insider, probiotics might even help people perform better when under stress.

“The microbes in your gut can affect your health in many different ways,” Eastwood said.

Here’s some of what we know about probiotics and brain health.

Your gut and brain are intimately connected

Your gut and brain are intimately connected, a partnership known as “the gut-brain axis.”

What affects the brain can affect the gut, and vice versa. That’s why you might have butterflies in your stomach when you’re nervous, Eastwood said.

The connection is so strong that bouts of GI conditions like IBS or Crohn’s disease can trigger mental health issues like depression or anxiety, according to Harvard Health.

Scientists are not yet entirely sure how these two systems work together. “Understanding exactly how these gut bugs affect your brain is still a bit of an unknown,” Eastwood said.

Probiotics can prevent the natural decline of cognitive abilities

As we age, our cognitive functioning, which includes memory and executive functioning, naturally declines.

Eastwood and her team published a 2021 Review who found that taking probiotics daily can reduce cognitive decline in otherwise healthy older adults.

“Taking a probiotic supplement could be particularly helpful just in mitigating that natural decline and maintaining cognitive function longer,” Eastwood said. Eastwood said this could be particularly useful as people continue to work they live longer.

The review also found that a daily probiotic may help improve cognitive performance in older adults who have mild cognitive impairment or Alzheimer’s disease.

While these findings are exciting, Eastwood said more and better research is needed.

Recently, a study presented at the American Society for Nutrition meeting in July of this year that found that older adults who took a probiotic had cognitive improvement compared to those who took a placebo.

Probiotics can also help reduce stress

Probiotics typically won’t improve cognitive functioning in younger people because “they’re already working at a ceiling,” Eastwood said. But “where you see an effect in younger adults is if they’re stressed.”

Sometimes, Eastwood said, if you’re stressed, your cognitive performance declines. But in the same 2021 review, “we find that if you take probiotics, you get this kind of buffering effect so that it reduces that decline.”

In other words, taking probiotics can help maintain normal cognitive functioning despite stress.

“In young adults who are taking exams or going through a particularly stressful time, that’s perhaps what could be beneficial,” Eastwood said.

Most studies on probiotics report that people take them daily for four weeks to six months, Eastwood said. In a study 2019, women aged 18 to 40 who took probiotics daily for 28 days performed better on a stress task than those who took a placebo.

We don’t yet know which strains are the best

Because probiotics research is still in its early stages, we don’t yet know which strains of probiotics may be most helpful for cognitive function.

If you’re interested in trying a probiotic, Eastwood recommends a multi-strain probiotic that contains a combination of the most researched strains including species of lactobacilli, bifidobacteria and lactococci.

And as with any new supplement, you should check with your doctor first to make sure it’s safe for you.