You might have taken probiotics, the live bacteria or “good” bugs that help restore and maintain a healthy digestive system, when you’ve had a bout of gastro upset or after you’ve finished a round of antibiotics, but there’s more to the story than that. New research is proposing that probiotics may also be good for a host of other problems.

A recent study in the American Heart Association journal Hypertension found that probiotics may reduce blood pressure. Researchers looked at nine previous studies on the connection between probiotics and blood pressure and found that people who’d been on probiotics at least eight weeks had small reductions in both systolic and diastolic blood pressure (both the top and bottom BP number). The reductions were largest in those with the highest blood pressures.

Although the mechanics of exactly how probiotics reduced blood pressure are not understood, scientists speculate that probiotics have an overall beneficial effect on health — including things like improving cholesterol, reducing blood glucose and insulin resistance, and helping regulate hormones that control blood pressure.

What’s more, this could be the tip of the iceberg when it comes to probiotics.

“It’s natural to think of people taking probiotics as a (gastrointestinal) product,” said Dr. Amesh Adalja, a senior associate at the Center for Health Security at the University of Pittsburgh Medical Center.

“However, when we talk about something called the microbiome, probiotics interact with the immune system and offer a host of benefits to diseases like (Clostridium difficile, a bacterial overgrowth that attacks the intestines) and irritable bowel disorder,” Adalja said, “but they also may play a role in everything from autoimmune disorders like rheumatoid arthritis, eczema, autism and others.”

The microbiome is the population of more than 100 trillion microorganisms that live in our body — gut, mouth, skin and elsewhere. They’re needed for digestion, to prevent disease and to halt bacteria from invading the body. If we establish that the microbiome is altered after probiotics, it's feasible that disease paths can be altered as well.

“In the future, in almost every condition and every disease where the microbiome plays a major role, probiotics may alter the way the microbiome interacts with the immune system, making them effective in altering disease,” Adalja said.

He said most people can safely take probiotics unless they are immune suppressed; then they should check with their physician before trying them. A typical daily dose is 3 billion to 5 billion live organisms. Most over-the-counter supplements and some yogurts will list the organism count and type of probiotic.

Lactobacillus AcidophilusHowever, probiotics are not standardized, meaning ingredients may differ from what’s stated on the label. The National Yogurt Association now has a seal on food labels promising “live active cultures,” which indicates that the product had a minimum number of Lactobacillus bacteria (seen at right) when manufactured.

At some point, probiotics might be regularly prescribed for a variety of conditions. Here’s a look at some promising probiotic links to health.

Anxiety and depression

A recent study found that people who took two probiotics — Lactobacillus helveticus and Bifidobacterium longum — had lower anxiety and better stress management compared with people taking a placebo. Researchers are looking at probiotics shown to have anti-inflammatory effects; both depression and stress are associated with inflammation. Scientists think intestinal microbial balance might alter the regulation of inflammatory responses and, in so doing, affect mood and behavior.


A California Institute of Technology study showed that feeding mice the bacteria from a healthy human gut reduced autism behaviors. The research adds to growing evidence of a gut-brain connection in autism spectrum disorder. Based on the findings, clinical trials of probiotic treatments for autism are getting underway.

Endurance athletes

A study in the British Journal of Sports Medicine found that introducing the friendly bacteria to sick endurance athletes improved their upper respiratory illness and cut their sick time by more than half vs. subjects who had a placebo. Future work could examine whether probiotics help muscles recover faster from stress such as endurance training.


The friendly bacteria might also hold some promise for skin disorders such as eczema. A 2008 report published in the American Journal of Clinical Dermatology found that probiotics could aid the prevention and treatment of atopic dermatitis, or AD. Lactobacillus rhamnosus GG appeared to be effective in preventing AD, a common type of eczema.


Natural gut bacteria play a role in the development of obesity. A 2012 study reported that bacteria residing in the large intestine might slow energy-burning brown fat and in turn contribute to the development of obesity. "The types of bacteria you have in your gut influence your risk for chronic diseases," Adalja said.  

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Inset photo (Lactobacillus bacteria): Bob Blaylock/Wikimedia Commons