Your digestive system comprises a complex series of organs spanning about 30 feet in length when stretched all the way out, from mouth to anus. This system carefully breaks down the food you eat, extracting all the vitamins and nutrients held within and eliminating any unused material as waste. When it works right, your digestive system is the foundation to good health and gives you the fuel you need to thrive.1
However, digestive problems are becoming more prevalent. According to the National Institutes of Health, an estimated 60 to 70 million people in the United States are affected by a digestive disease or disorder. That contributed to about 21.7 million hospitalizations in 2010 and 48.3 million ambulatory care visits that same year. These disorders range from chronic constipation to gastrointestinal infections to viral hepatitis.2
While many of these disorders can be treated or managed, they can cause pain and discomfort and harm your general health and wellbeing. Many people turn to probiotics, most commonly yogurt and kefir. Let’s take a closer look at probiotics, how they can help your digestive system, and the best probiotic yogurt and kefir you can get.
What are Probiotics?
Generally, probiotics are considered the “good” bacteria and yeasts that live within your body. Experts generally consider probiotics as live microorganisms that can provide health benefits when present in adequate amounts in the body. Probiotics are best known and studied for aiding your digestive system and helping your body extract and absorb nutrients from foods, though some studies also suggest that probiotics may help to support immune functions.3
You can find a wide range of probiotic bacteria in foods, but the two most common tend to be Bifidobacteria and Lactobacillus. The latter is known to produce lactic acid and lactase, the enzyme that breaks down the milk sugar lactose.4
How Do Probiotics Work?
Your digestive system contains a complex microbiome of organisms, collectively known as your gut flora. This includes bacteria, yeast, and viruses. Most of your gut flora exists in your large intestine, and they play an important role in your overall health. The gut flora is responsible for creating certain vitamins, including vitamin K and some B vitamins. Your gut flora also turns dietary fiber into short-chain fats that act as nourishment for your gut wall. They also keep potentially harmful microbes from entering the rest of the body.5
However, your gut flora is highly sensitive to various environmental factors, particularly antibiotics. Antibiotics target bacteria, but they generally don’t have a means of discerning between helpful and harmful bacteria. This can cause an imbalance between your good and bad bacteria known as dysbiosis. Dysbiosis can cause a variety of symptoms, most prominently an upset stomach. Other common symptoms of dysbiosis include:
This is where probiotics come in. By consuming probiotic-rich foods, you can rebalance your gut flora and the pH levels in your gut to reduce bad bacteria and their harmful effects.
Yogurt vs Kefir
Yogurt is a well-known dairy food often made from cow’s milk or cream (though dairy alternatives do exist). The milk is heated, pasteurized, and homogenized to kill any potentially harmful bacteria before bacteria starters or cultures are added. The bacteria required for fermentation are Lactobacillus bulgaricus and Streptococcus thermophilus. Some yogurt manufacturers may also add Lactobacillus acidophilus or other bacteria for further probiotic benefits. These bacteria work to metabolize lactose, the main sugar in milk, and turn it into lactic acid, which provides yogurt’s characteristic tart flavor.7
Kefir is a cultured, fermented beverage that is similar in taste to a yogurt drink. However, kefir is made using starter “grains.” These grains are actually clumps of yeast, bacteria, casein (milk proteins), and complex sugars. No other milk culture forms grains. These grains are added to milk, which starts the fermentation process, allows for the growth of friendly bacteria in the milk, and creates the cultured product. Before drinking the actual kefir, the grains are strained out and can be added to another batch of milk to make more kefir. Kefir can be made from most any type of milk, including:
Because kefir is fermented, it is generally fine for people who are lactose intolerant.9
Kefir and yogurt tend to get lumped together often, and it’s true that they do share various characteristics. Both are traditionally made from dairy and friendly bacteria that incorporate a creamy, tart flavor.
Kefir generally has more fat than yogurt, though may make up for that by having more protein and probiotic bacteria. Kefir also contains active yeasts that may offer benefits similar to probiotics. Yogurt is thicker, while kefir is thinner and best enjoyed as a beverage. In terms of fermentation, kefir generally ferments at room temperature, while yogurt cultures usually start at a higher heat.
That said, both yogurt and kefir are good sources of probiotics and a wide range of other nutrients, including:
- Some B vitamins
What to Look for in Probiotic Yogurt and Kefir
All yogurts are fermented with bacteria and can potentially help your digestive tract, but not all yogurts offer the same health benefits. Although bacteria are required to make yogurt, some of that bacteria dies based on the manufacturing process, packaging methods, and storage conditions, meaning that the yogurt may not contain enough of the bacteria to impart any true probiotic benefits.11
Regardless of the base ingredient used in the yogurt, the main thing to look for is some mention of “live and active cultures” on the label. Some yogurts have a “Live and Active Culture” seal from the National Yogurt Association. The National Yogurt Association has developed standards for probiotics in yogurt. For yogurt to be considered healthy, it must contain at least 100 million cultures per gram (which is what the NYA seal denotes). Frozen yogurt has to contain at least 10 million cultures per gram.
If the label doesn’t outright state that it contains live and active cultures, check the ingredient label, which should list the bacteria that were used in the fermentation process and any bacteria that may have been added.
The main thing you want to look out for is yogurts that have pasteurized or heat-treated after the probiotics have been added. Pasteurization is important to killing harmful bacteria, but it also eliminates helpful bacteria in the process. Yogurts that have been pasteurized should have a label that says “heat-treated after culturing.”
Kefir is a little harder to come by and mainly found in health food stores. Most people make their own kefir using kefir starter cultures. Powdered cultures are made in labs and are generally meant to be used once. Kefir grains, on the other hand, are reusable, and given the right amount of care, they can be used indefinitely. However, kefir grains need a constant source of food, which means more maintenance than you may be prepared for. Generally, grains are more economical and nutrient dense, but starter cultures are better for those who only make kefir periodically.12
Other Things to Look For
Remember that both yogurt and kefir contain more than just probiotics. The probiotics may not be worth it for the ingredients that the manufacturer adds.
Sugar is the biggest concern, turning yogurt and kefir from probiotic-rich health foods to unhealthy treats. Yogurt and kefir both generally contain some small amount of sugar naturally thanks to the lactose in the milk. However, some manufacturers will add more sugar to make the yogurt or kefir sweeter and more attractive to the average American. Plain yogurt contains about 10 to 15 grams of carbs per cup, but yogurt containing sugar or added flavors can contain more than 30 grams of carbs per serving.
Plain, unflavored yogurt tends to be the best option if you want to avoid the added sugar. For more flavor, you can add fresh fruit to your yogurt.13
Yogurt can be made from whole, low-fat, and fat-free milks, leading to low fat or full fat varieties of yogurt. Most health experts recommend the low-fat option to cut down on calories, but yogurts with reduced fat content tend to also contain the most added sugar as a means of compensating for flavor from the lack of fat.14
Full fat might seem intimidating, but the fats found in dairy may have their potential health benefits. Dairy contains natural fats that are unlike the more harmful fats found in heavily processed foods. For example, one of the fats known as conjugated linoleic acid (CLA) has been found to potentially help reduce body fat, improve blood sugar regulation, and improve cardiovascular health.15
Ultimately, the best yogurt can vary from person to person. A good rule of thumb is to keep it simple. Find a yogurt that uses few ingredients and added sugars while still containing active cultures. Most people recommend making kefir at home, which is generally easier than making yogurt at home and allows you to better control what goes into your drink.
If you would like to get the benefits of probiotics without having to worry about consuming additional calories you can take a high-quality probiotic supplement such as Nexabiotic® Advanced which has 23 probiotics in 1 easy-to-swallow capsule.