Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content

Take the guesswork out of eating right with new meal plan recipes.

Content starts here
CLOSE ×
Search
Popular Searches

Cognitive Assessment

Six Habits to Support Your Brain Health

Memory Loss - Is It Inevitable

Staying Sharp Recipes

High Blood Pressure and Memory Loss: What's the Link?

Suggested Links
Brain Health 101 Challenge Learn About Staying Sharp's Scientific Research Program Your Brain on Music I Am Memory [video] Make Sleep Your Super Power The Power of Social Connections
Red Membership Card

AARP MEMBERSHIP

Join AARP for just $15 for your first year when you sign up for automatic renewal. Gain instant access to exclusive products, hundreds of discounts and services, a free second membership, and a subscription to AARP The Magazine.

 

Join Now
Renew Now
120x30-AARP-logo-red
Join
Renew

UHCRA

Prudential

One Pass

MS15

Back 

Back 

6 Pillars of Brain Health

Close Menu

Be Social

Engage Your Brain

Manage Stress

Ongoing Exercise

Restorative Sleep

Eat Right

Sanjay Gupta, M.D. smiling in front of a bookshelf

Challenges

Brain Health 101

A group of women running on grass by a body of water

Articles

6 Habits to Support Your Brain

An overhead shot of people walking in a line over a painting of a brain on the ground

Best Of

Your Brain on ... Series

Michelle C. Carlson, Ph.D., of the Johns Hopkins Center on Aging and Health

Videos

6 Healthy Habits That Can Help Support Brain Health

Join
Renew
Enroll: Automatic Renewal
Rejoin
Leaving AARP.org Website

You are now leaving AARP.org and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

Continue Cancel
12f75a72-12fc-41f3-9f42-f7be93c040ab

Quiz: How Well Do You Know Your Gut Microbiome?

Test your knowledge of the trillions of microscopic organisms living in your colon — and the role they play in brain health

By

Christine Richmond

 
Updated June 03, 2025
Updated June 03, 2025
A man and woman with illustrations of their intestines with colorful bacteria on their stomachs
SolStock/Getty Images

Question 1 of 8

True or false? The bacteria in your body outnumber your own cells 10 to one.

This widely ​​cited data was officially debunked in a 2016 paper in PLoS Biology, which estimated the adult human cell count closer to ​​30 trillion and our bacterial cell count at about 38 trillion.

Question 2 of 8

The gut microbiome has been linked to which aspects of brain health?

It's hard to believe that the tiny microbes in your gut could influence so much, but ​​research has found that the gut microbiome impacts the brain from the beginning of life onward.

Question 3 of 8

Which of the following substances is NOT produced in the gut?

Many compounds that are vital to your health are made in your gut. This includes the natural mood booster ​​serotonin; ​​short-chain fatty acids, which​ are ​important for ​metabolism; and ​​vitamin K, essential for blood clotting and bone health. But food is your only source of ​vitamin C.

Question 4 of 8

Which of these can change the composition of your gut microbiome?

The composition of your gut microbiome is shaped by many lifestyle factors, including what you eat, the prescriptions you take and ​maybe even ​​​​​the pets in ​your ​house.

Question 5 of 8

What do experts recommend eating more of to benefit the gut microbiome?

Much of the fiber in the food you eat reaches your colon undigested and gets broken down by your gut microbes, resulting in the production of beneficial short-chain fatty acids. There’s evidence that eating more dietary fiber can improve the diversity of your gut microbiome, too, which is a good thing.

Question 6 of 8

During what stage of life do our gut microbiomes change the most?

Although your gut microbiome is always fluctuating in response to your diet, your environment and even the amount of ​​sunlight you get, ​​evidence suggests it changes the most in the first two to three years of life.

Question 7 of 8

Which of the following is a good option for restoring gut microbiome balance after taking antibiotics?

Your best bet is eating ​fermented foods like sauerkraut or kimchi, which provide naturally ​​occurring beneficial bacteria. Research suggests probiotic supplements are often ineffective and may even delay recovery.

Question 8 of 8

True or false? Modern life is making our gut microbiomes less diverse.

People living in industrialized areas tend to have less diverse gut microbiomes, according to a growing body of ​​research. This is likely due to a combination of factors, including less time spent outdoors and a ​low-fiber ​Western diet high in fat and sugar​.​

You have unanswered questions. Please go back and complete those questions to finish the quiz.

To learn more about your gut microbiome and its close relationship with your brain, visit Staying Sharp.

0 Correct
0 Incorrect

More From Staying Sharp

Benefits Recommended For You

See All

Legal Disclaimer: Staying Sharp, including all content and features, is offered for informational purposes and to educate users on brain health care and medical issues that may affect their daily lives. Staying Sharp is based on a holistic, lifestyle approach to brain health that encourages users to incorporate into their daily lives activities that are associated with general wellness. Nothing in the service should be considered, or used as a substitute for, medical advice, diagnosis, or treatment. Features including the Cognitive Assessment and Lifestyle Check-Ins, Additional Tests, exercises, and challenges assess performance at a particular moment in time on certain discrete cognitive tasks. Staying Sharp games are intended for entertainment and recreational purposes only. Various factors may affect performance, including sleep, tiredness, focus, and other social, environmental, or emotional factors. Performance is not indicative of cognitive health and not predictive of future performance or medical conditions.

 

Unused AARP Rewards points expire 12 months after they are earned, in monthly batches on a rolling basis.