Probiotics are live microorganisms that, when consumed in adequate amounts, can provide positive health effects. Currently, the common probiotics on the market can be mainly classified into several categories:
1. Lactobacillus
Lactobacilli are the most common type of probiotics, widely used in foods, dietary supplements, and clinical research. Major species include Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus gasseri, Lactobacillus reuteri, Lactobacillus bulgaricus, and Lactobacillus johnsonii.
These lactobacilli can participate in fermentation within the gut, help break down lactose, regulate gut microbiota balance, and produce lactic acid to lower intestinal pH, thereby inhibiting the growth of harmful bacteria. Different strains have unique functional properties, such as supporting immune regulation, alleviating constipation, or reducing diarrhea. Selecting the appropriate species and strains of Lactobacillus is crucial to obtaining the health benefits of probiotics.
2. Bifidobacterium
Bifidobacteria are another important group of probiotics, mainly colonizing the human gut and playing a key role in maintaining intestinal health. Common species include Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium adolescentis, and Bifidobacterium infantis.
Bifidobacteria can ferment carbohydrates to produce lactic acid and acetic acid, lowering intestinal pH and inhibiting harmful bacteria. They also help regulate gut immune function, improve constipation or diarrhea, and provide important protection in the intestines of infants. Different strains have slight functional differences, so choosing scientifically validated strains is essential for the probiotic's health effects.
3. Other Gram-Positive Bacteria
Apart from Lactobacillus and Bifidobacterium, there are other common Gram-positive probiotics that also play important roles in gut health. Common species include Bacillus coagulans, Propionibacterium freudenreichii ssp. shermanii, Enterococcus faecalis, Lactococcus lactis, and Streptococcus thermophilus.
Each of these species has unique functions. For example, Bacillus coagulans is acid- and heat-resistant, surviving temporarily in the gut to help balance microbiota; Streptococcus thermophilus is commonly used in fermented dairy products and supports lactic acid production to inhibit harmful bacteria; Lactococcus lactis and Enterococcus faecalis contribute to digestion, maintaining gut barrier function, and immune modulation. Functional effects vary among strains, so selecting scientifically validated strains that suit individual needs is important to maximize probiotic benefits.
4. Yeast
Yeast probiotics are relatively less common in foods and supplements. A typical example is Kluyveromyces marxianus. Although they can have some regulatory effects on the gut environment, Lactobacillus and Bifidobacterium remain the most widely used and well-studied probiotics.
It is important to note that even strains within the same species can have very different functions. Therefore, microorganisms without scientific evidence and strict validation should not be strictly considered "probiotics," even if they belong to the above genera.
In recent years, China's probiotic market has grown rapidly, but the market quality is uneven. Many products marketed as imported probiotics may actually be ordinary lactic acid bacteria and may not have undergone efficacy or safety testing. When choosing probiotic products, it is essential to focus on scientifically validated strains, live bacterial counts, and actual efficacy, rather than judging the product based solely on brand or advertising.