Why Some Probiotics Work for Others but Not for You

Benefits of Probiotics
Probiotics influence the immune function of the intestinal lining. Exposure of the gut-associated lymphoid tissue (GALT) to microorganisms promotes the maturation of immune cells. Probiotics also help strengthen the integrity of the gastrointestinal (GI) tract, which acts as a barrier against the invasion of pathogens. Some strains of lactobacilli have been shown to affect the production of proteins that form tight junctions, thereby decreasing gut permeability. Other strains may stimulate the production of mucus, which further strengthens the gut barrier. Many of the effects of probiotics are mediated by cytokines. They enhance the production of anti-inflammatory cytokines while reducing the levels of pro-inflammatory cytokines. Common probiotic bacteria used in foods and dietary supplements include Lactobacillus, Lactococcus, and Streptococcus.

Probiotics and Prebiotics
Food sources of probiotics are mainly fermented products. These include fermented dairy products such as yogurt, cheese, buttermilk, and kefir. Non-dairy alternatives include fermented soy products (such as soy, miso, and tempeh) and fermented vegetables like sauerkraut and kimchi. Prebiotics are ingredients (typically carbohydrates ) that are not well digested by human enzymes but serve as a fuel for beneficial bacteria in the gut. Prebiotics commonly include fructooligosaccharides (FOS), galactooligosaccharides (GOS), and trans-galactooligosaccharides (TOS).

Choosing the Right Probiotic
It is important to identify the specific bacterial strain when using probiotics. Some bacteria, such as Escherichia coli and Clostridium difficile, can cause harmful reactions, including diarrhea, dehydration, and in severe cases, death. In addition, some individuals cannot tolerate high colony-forming units (CFU) of probiotics. This intolerance indicates an excessive amount of bacteria already present in the body, making it difficult to tolerate additional bacterial strains, even if they are considered beneficial. For this reason, it is important to first assess the presence of potential pathogens. If harmful bacteria are detected, they should be addressed using antimicrobial botanicals such as oregano, berberine, and clove before introducing probiotics. The type of food source is also an important consideration. For example, fermented soy products are not suitable for individuals with estrogen dominance because soy contains compounds with estrogen-like activity. In such cases, probiotic supplements are a better option than fermented soy foods.

Personal Experience
Based on my personal experience, I noticed improved digestion when taking probiotic supplements compared with relying solely on plant-based food sources. However, I experienced adverse reactions when consuming tofu. I developed two to three deep bumps on my face after eating tofu. Tofu is a soy food. I did not experience this reaction during childhood; it only began after I started and later stopped using facial products containing parabens and tretinoin, which resulted in painful periods and digestive problems, which have now been resolved.

To gain the full benefits of probiotics, it is important to look for a list of specific strains on the label when choosing a supplement. If any adverse reactions occur, a stool test can help identify whether excessive bacteria are already present in the gut. Individuals with estrogen dominance should avoid soy-based foods.