What Do Probiotics Really Do and Do You Need Them?



Natural probiotics are found in the body. People actually have over 1,000 different species of bacteria in the gut, and everybody has a unique combination of between 250 and 500.

Each person’s bacterial profile is as unique as their individual DNA. “Those who are looking to support immune and digestive health or have recently taken antibiotics should consider a probiotic supplement, according to Vitamin Shoppe Nutritionist Brian Tanzer, MS, CNS says.

You may want to take a probiotic, he adds, if you answer yes to one or more of the following questions: Do I have digestive problems? Have I recently taken antibiotics? Am I chronically stressed? Do I have a diet high in refined sugar and processed carbohydrates? Do I have immune challenges or get sick often?


Probiotics help balance the good and bad bacteria in the body. “The ratio between ‘good bacteria’ and other bacteria in the body is one of the critical factors in determining your overall health,” Tanzer says. “The good bacteria [are] essential for many bodily functions, including the proper development of your immune system and the digestion of food and absorption of nutrients.”

The best way to restore beneficial bacteria in the gut is to create acidity, which promotes the growth of various Lactobacillus bacteria—the ones with well-known beneficial effects. One effective ways to accomplish this is by taking probiotic supplements.


Probiotics are not all alike. A good range for a daily probiotic can be between 5 and 30 billion Colony-Forming Units (CFU), which are used to measure probiotics potency, Tanzer says. People should keep three tips in mind when choosing a probiotic, according to him.  

1. If you are looking for a probiotic to take every day, try a multi-strain probiotic. CFUs can range from 1 billion up to 200 billion. “CFU count isn’t that important when using a probiotic every day.  Start with 5-10 billion CFU and see how it works for you,” Tanzer adds.

2. “If you are just finishing up a course of antibiotics and you have chronic digestive and immune issues, look for a combination of lactobacillus and bifidobacteria with a CFU count of at least 30 billion.”

3. You can find probiotics in many forms – capsules, tablets, gummies, powders, and even chewables.  “Powders are convenient, especially for those who prefer not to swallow a pill. Chewables and gummies can also work well for kids,” Tanzer says.


Some foods that have probiotics are dairy products, organic Kefir, sauerkraut, kimchi, miso soup, yogurt, and tempeh.

“It’s best to gradually add fermented foods into your diet as you may feel a little more bloating than normal until your body and gut bacteria adjust,” Tanzer says.

The best time to take a probiotic supplement is between meals, ideally in the morning or in the evening, according to Tanzer. You don’t have to take them in supplement form. “Fermented foods can offer similar benefits to supplements, by providing more good bacteria, and supporting a proper balance of gut bacteria,” he says.


A recent study suggests that consuming probiotics promotes weight loss and reduces Body Mass Index (BMI). But this has not been proven beyond a doubt. “There is a lot of research in the field of probiotics and the microbiome in general. What we can conclude at this point is that the bacteria in our gut play a significant role in digestive and immune health, with other benefits currently under research,” Tanzer says.  

One of the areas being investigated is the role of the microbiome in nutrient metabolism and weight management.  Some preliminary data has shown that some probiotics greatly impact the body’s ability to digest and absorb nutrients, and may influence food intake and body weight.  “At this point it’s too early to draw any conclusions or make any specific recommendations for probiotics and weight management,” Tanzer adds.

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