Recent Blog Articles
Improving access to hearing aids
Can mindfulness change your brain?
Five lifestyle factors that can help prevent gastroesophageal reflux disease
Transient ischemic attacks: Varied symptoms, all important
5 inflammation-fighting food swaps
Is IBD an underrecognized health problem in minority groups?
Sickle cell disease in newborns and children: What families should know and do
COVID-19 vaccines for children and teens: What we do - and don’t - know
Happy trails: Take a hike, now
Sleep well — and reduce your risk of dementia and death
What you should know about: Probiotics
When you consider ways to stay healthy as cold and flu season approaches, consuming live bacteria may not be at the top of your list. But not all bacteria are bad for you. In fact, "good" bacteria found in food and dietary supplements may help you ward off illness this winter and throughout the year. The supplements are called probiotics. "Probiotics have been shown to secrete protective substances which turn on the immune system and prevent pathogens from taking hold and creating major disease," says Dr. Allan Walker, director of the Division of Nutrition at Harvard Medical School and a world-renowned expert in the probiotics field.
The bacteria balance
Your lower gastrointestinal tract is home to 100 trillion microbes, most of which help digest food, fight harmful bacteria, and regulate your immune system. Such helpful microbes are "good bacteria." An imbalance of the good and bad bugs in your gut can make you sick. For example, germ-killing antibiotics may disrupt the balance, leading to diseases that cause diarrhea. Imbalances may also lead to certain autoimmune diseases and allergies.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.