What is Probiotic Food?

Tricia Christensen
Tricia Christensen

Probiotic food is any food that contains microorganisms known to be helpful to human digestion. Scientists and health experts use the word “probiotic” for a range of organisms that promote intestinal health by balancing digestive acids and assisting with the breakdown and transportation of waste. Some foods, like certain sea kelp and algae, contain helpful bacterial cultures naturally; they may also grow as a result of fermentation or pickling. Food manufacturers can add them intentionally as well, as is often the case with yogurt and other dairy products.

Yogurt is one of the most popular types of probiotic food.
Yogurt is one of the most popular types of probiotic food.

Beneficial Properties

Unlike antibiotics, which kill harmful bacteria in the body, probiotics add helpful bacterial cultures, almost always to the digestive tract. The intestines are naturally teeming with bacteria that help process food and eliminate waste, but these processes are not always as efficient as they could be. Poor nutrition, imbalanced hydration, illness, and other environmental factors can also lead to a number of digestive troubles. Not all medical professionals agree that probiotics can cure problems like diarrhea, persistent constipation, or irritable bowel syndrome, but there is wide consensus that they can at least help in most cases.

Pitcher of acidophilus milk.
Pitcher of acidophilus milk.

Prevalence in Dairy Products

Food manufacturers in many countries artificially introduce probiotics into milk, yogurt, and some cheeses as a way of making them more digestible. Raw cow and goat milk contains some of these bacteria, but not always very much. Human breast milk, on the other hand, typically has very high levels of probiotic cultures, which many experts believe helps infants’ digestive tracts mature.

Pickled cucumbers.
Pickled cucumbers.

Researchers began experimenting with the addition of Lactobacillus acidophilus bacteria to commercial milk in the early 1900s in both Europe and North America after medical professionals began noticing an increase in patients with lactose intolerance and other digestive troubles thought to be caused by dairy products. Adding the cultures can make milk more easily digestible without altering its taste or nutritional composition, so people still get the benefits, like calcium and protein, without as much stomach upset. Modern day manufacturers do not usually fortify milk with cultures automatically, though probiotic milk — usually called acidophilus milk — is available in many markets, often as an alternative for those with lactose intolerance.

Some sea kelps are a natural probiotics.
Some sea kelps are a natural probiotics.

Helpful bacteria additions are standard in most yogurt products, however. Any yogurt that says “live and active cultures” on its labeling contains probiotics. These cultures are usually added to help the yogurt thicken during processing, and the digestive benefits are often something of an added bonus for the consumer. Some yogurt manufacturers add more cultures than are strictly needed in order to boost the probiotic effect of the final product; many of these are sold with promises of improved regularity or marketed as a digestive “wonder food,” though the accuracy of these claims is somewhat controversial.

Breast milk contains a high amount of probiotic cultures.
Breast milk contains a high amount of probiotic cultures.

Fermented Foods

L. acidophilus is only one of many bacteria that can help regulate digestion. Other bacterial strains in the Lactobacilli genus, as well as some Bifidobacterium species, grow in fermented foods. These bacteria generally occur naturally, though some food manufacturers will take steps to encourage their presence. Miso, sauerkraut, and the fermented soy product sold in many places as tempeh are a few common examples of foods high in these cultures.

Fermented foods, like sauerkraut, are high in probiotic cultures.
Fermented foods, like sauerkraut, are high in probiotic cultures.

Preserved and Pickled Vegetables

Pickled vegetables may also be good sources of probiotics. Homemade pickles typically have higher concentrations of helpful bacteria than mass-produced or commercially prepared products, as many of the preservatives common in store-bought foods restrict bacterial growth. Much depends on the process and the vegetable at issue, however.

Sea Plants

The sea plants pirulina, chorella, and blue-green algae, which are eaten in many cultures, are naturally high in Bifidobacterium bacteria when consumed fresh. The probiotics in these plants do not usually stay alive for very long once removed from the ocean, which means that they have to be eaten relatively quickly in order to provide any digestive benefit. It is also important that they be eaten raw, since cooking the plants usually kills the bacteria.

Lifespan Concerns

Algae are not the only probiotic foods with a limited shelf life. Like most living things, bacteria only thrive in certain conditions, and they will die at some point. As a result, many of these foods have very strict expiration dates. Individuals who eat out of date products will not necessarily be harmed by them, but they may not produce any benefit, either. Most active cultures will stay alive under refrigeration, pressure, or liquid suspension for anywhere from a week to 10 days once they have been exposed to oxygen. Heating, freezing, and aggressive agitation can cause the bacteria to die more quickly.

Manufactured Supplements

Some people choose to take probiotic supplements in addition to looking for foods rich in these cultures. Most are marketed as “combination pills” that contain a number of different bacterial strains. Medical professionals sometimes recommend these to patients with chronic digestive troubles, particularly those who suffer from irritable bowel syndrome, and when taken with food, they can sometimes help the body work more smoothly. There is not much evidence showing that this sort of regimen is any better than simply eating foods that contain live and active cultures, but this hasn’t stopped many people from at least giving supplementation a chance.

Potential Side Effects

Probiotic foods are not always helpful for everyone, and bad reactions have been documented, particularly in people who begin aggressive diet programs without any prior exposure to the bacterai. Stomach upset, flatulence, and loose stools are a few of the symptoms people may experience when suddenly introducing large quantities of bacteria into their diet. Most health experts recommend starting gradually, often by eating a single serving of probiotic-enhanced food at a time. Over a span of days or weeks, quantities can be slowly increased to build tolerance and condition the intestines.

Some types of algae are farmed because of their probiotic characteristics.
Some types of algae are farmed because of their probiotic characteristics.
Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent wiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

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Discussion Comments


"Probiotics" means "for life."


What does the word "probiotic" mean, literally?


@Bigmetal: Yogurt biotics do not colonize the gut, so in order to get any benefits you must keep eating it. Milk products themselves will cause problems, so you are better off getting probiotics from a different source.


The very very best treatment/food for stomach digestion problems, e.g., IBS and for allergy problems like eczema, hay fever, asthma, is raw, unpasteurized milk. It cured my son (aged 35) of terrible eczema in his ears which he's had for 25 years! Also he had bad digestion. All cured up in less than two months.

Drink half a liter a day. Also good is fermented vegetables which are full of bacteria but not as much as the milk. We do not have enough digestive, immune giving bacteria in our stomachs. Nothing but nothing worked for him until I heard a long program on BBC radio about raw milk. I buy seven litres a week from the farmers market or direct from the farm.


@bigmetal: I've been using probiotics for two years now. My mother has ulcerative colitis so I wanted to protect myself from that disease and others.

Home made yogurt is the best yogurt to eat. Store bought yogurt usually does not contain enough live active cultures to be sufficient (you need billions). I found taking refrigerated probiotic capsules to be effective as long as you take a couple billion a day. Genuine fermented foods such as sauerkraut (Bubbles) which you can find at Whole Foods Market is good. Bees Pollen and flax seeds are also good at Whole Foods Market.


I have crohn's disease and even with medication I still had very loose stools until I started taking probiotic supplements. You need to get the right kind though, as they die really fast in pill form, so find someone who can ship it to you in less than two days.

When I take probiotic supplements it helps me digest foods better and have more normal stools.


I read online that this also helps speed up the healing for canker sores.


I've had IBS for many years and keep it under control with diet, no medications. One key is to eat a lot of fiber, if you tend toward constipation. But, you must build up the amount gradually or you will develop painful gas pains. I try to eat at least 30 mg. of fiber daily, easy when one eats a high fiber cereal in the a.m. and whole grain breads and fresh veggies all day. These are healthy foods for a variety of reasons anyway. Good luck.


I was diagnosed by my physician to have IBS. I am an extreme fitness person and I eat very well 80 percent of the time. Can i keep my IBS under control with a good diet and not have to take medications?


In what way are probiotic foods beneficial to autism disorder patients?


is probiotics helpful to someone who has problems with their digestive systems eg bloating stomach ?


my son had to go on 2 rounds of antibiotics for ear infections and pneumonia. i have been giving him yogurt with the extra added probiotics to help him replace the bacteria in his digestive tract...is this really all that effective? are there other foods i can be giving him that can help him?

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