The popularity of probiotic-infused foods and dietary supplements have skyrocketed as a means of using “good” bacteria to combat “bad” bacteria. While 3.9 million Americans rely on probiotic supplements,[1] some nutrition experts, like registered dietitian Mindy Haar, Ph.D., question their efficacy and safety.

“Probiotic supplements are commonly used to ‘correct’ the balance of bacteria in the digestive system, but most people don’t realize they may be ineffective or even counterproductive,” says Haar, who serves as assistant dean, Undergraduate Affairs, New York Institute of Technology (NYIT) School of Health Professions.

Contending that probiotic supplements are not a universal digestive solution, she points to new studies by The Weizmann Institute,[2] which recommend an individualized approach. Researchers found the supplements were ineffective for many test subjects, and in some cases even worsened conditions, leaving probiotic balance unrestored for as long as five months. Additional findings[3] have linked probiotic supplements to bacterial overgrowth, which can increase risk of infection and delay the regrowth of the body’s healthy bacteria.

Haar maintains that the simpler and safer approach to restoring probiotic balance is through diet, with fermented foods like sauerkraut, yogurt, or kombucha tea. While these foods may not be at the top of everyone’s list, another easy fix is to increase fiber intake since fiber acts as a prebiotic promoting the growth of probiotics. While men require at least 30 grams of fiber per day and women 25 grams, most Americans fall short, averaging only 15 grams.[4]    

“The bottom line is that the benefits are uncertain and definite risks exist. A probiotic supplement may provide only a fraction of good bacteria, and may cause consequences, especially after taking antibiotics. However, small changes in diet can reliably – and safely – improve digestive health.”

Haar is available for comment/interview. Please contact Kim Tucker, NYIT Media Relations, at