The difference between Saccharomyces boulardii and Bifidobacterium bifidum mainly lies in the type of drug, efficacy, treatment and contraindication. 1. Type of drug: Saccharomyces boulardii is a fungal intestinal probiotic preparation, which is a prescription drug; while Bifidobacterium bifidum is a bacterial intestinal probiotic preparation, which is an over-the-counter drug. 2. Efficacy: Saccharomyces boulardii does not colonize the intestinal tract after oral intake, and produces a transient microecological regulation; whereas Bifidobacterium bifidum can occupy the surface of the intestinal mucosa with other anaerobic bacteria, inhibit the growth of pathogenic bacteria and promote the growth of beneficial bacteria. 3. Treatment: Saccharomyces boulardii is mainly used for the treatment of diarrhea in adults and children, and the diarrhea symptoms caused by intestinal flora dysbiosis; Bifidobacterium is mainly used for the treatment of intestinal dysbiosis caused by intestinal dysfunction, such as acute and chronic diarrhea, constipation, etc.. 4. Contraindication: Saccharomyces boulardii belongs to fungi, should be avoided and antifungal drugs taken at the same time, central venous catheter infusion patients, fructose or galactose intolerant patients should be prohibited. Bifidobacterium bifidum belongs to bacteria, should be avoided and antibiotic drugs, antacids, bismuth, tannins, medicinal charcoal, etc. at the same time, so as not to affect the efficacy. In addition, Saccharomyces boulardii may be taken with adverse reactions such as urticaria, intractable constipation, dry mouth, and fungemia; while no adverse reactions have been found with Bifidobacterium bifidum. When taking Saccharomyces boulardii and Bifidobacterium bifidum, it is recommended to consult a doctor in advance and take them in strict accordance with the doctor’s instructions, and not to self-medicate, so as not to delay or even aggravate the condition.