If you’ve browsed the aisles of your local health food or supplement store recently, you’ve probably seen bottles upon bottles of pills called “probiotics.” Next to them, or even included on the same packaging, might be things called “prebiotics.” These supplements have become very popular in recent years because of their proposed health benefits.

At first glance, these two things might seem like they are the same, but there are actually very important distinctions between them. Together, probiotics and prebiotics work to keep your digestive tract, immune system and overall health in great shape.

The gut microbiome and probiotics

Although bacteria are typically thought of as harmful, there are actually many types of beneficial bacteria that live on your skin and within your body. In fact, a large system of microorganisms, commonly referred to as the microbiome or microflora, lives in your gut and helps regulate digestive tract function and much more.

Probiotics are part of this microbiome. They are “good” bacteria and yeasts that help protect the gut from the overgrowth of harmful bacteria and keep the gut running smoothly.

The majority of your immune system also lives in the gut. Experts believe that poor digestive tract health (like not having enough good bacteria and/or having too many harmful bacteria) can make the immune system less effective and lead to other problems within the body.

If your microbiome is imbalanced, you may begin to suffer from things like diarrhea, irritable bowel syndrome (IBS), bloating and more. Probiotics help maintain this balance. Without probiotics, the gut, and by extension, your body as a whole, will be not able to function properly.

Our bodies naturally contain probiotics, but they can also be found in fermented foods like yogurt and kimchi, as well as in supplement capsules. There are numerous types, or strains, of probiotics, each of which provides its own benefits. Lactobacillus and Bifidobacterium are two of the most common probiotics for humans.

Taking probiotics, either through food or supplements, can help maintain the balance of good and bad bacteria in your gut. It can also replenish the good bacteria if they have been wiped out by something like antibiotics, poor diet or stress.

What are prebiotics?

Prebiotics are types of carbohydrates or fibers, that “feed” the bacteria in the gut. Prebiotics are often found in the non-digestible parts of many fruits and vegetables.

Because they are not digestible, these fibers travel through the stomach to the colon, where they are fermented in the large intestine. After fermentation, prebiotic fiber is able to feed the live bacteria in the gut, bolstering them and helping them thrive.

Essentially, prebiotic fiber acts as fertilizer for healthy probiotic growth.

How probiotics and prebiotics create a healthier you

When probiotics and prebiotics are taken together, your gut has everything it needs to stay balanced and healthy.

Taking probiotics helps introduce additional beneficial bacteria into your colon to support your digestive health, immune system and overall wellbeing. Taking prebiotics on top of this helps support the probiotics, giving them a better chance at survival in the gut and helping them support your health more easily.

Probiotics, with or without prebiotics, may assist in alleviating gastrointestinal discomfort, such as diarrhea, IBS and more. They may also support a healthy immune system and bolster the cells in the intestinal walls. These things could help you more effectively stave off illnesses. Some people even believe probiotics can help reduce inflammation, combat obesity and more.

Although prebiotics are not completely necessary, they help keep your GI tract as healthy as possible.

You can bolster your gut microbiome by eating foods naturally high in probiotics, including fermented foods like sauerkraut, yogurt and kefir, as well as foods naturally high in prebiotic fiber like wheat bread, oatmeal, asparagus and barley. Some foods or food combinations contain both probiotics and prebiotics and are considered “synbiotics.”

If you don’t like or don’t eat a lot of these foods, you can also get healthy doses of probiotics and prebiotics by taking supplements. Some supplements only contain probiotics or prebiotics, while others combine the two in a single dose.

Probiotics and prebiotics can be taken daily to promote general wellbeing. However, they are particularly important to take during or after rounds of antibiotics to help stabilize the balance of microbiota in your gut after antibiotics eliminate them.

When selecting probiotics, be sure to do thorough research on which supplements contain live bacteria and which bacterial strains are included. Speak with your doctor before taking probiotics to determine whether probiotics are appropriate for you based on your current health condition.

Over time, the combination of probiotics and prebiotics should help bolster your gut microbiota for life-long health.