How many probiotics per day
Pro Research Analysisby 
Searched over 200M research papers
Optimal Daily Probiotic Dosage: Insights from Recent Research
Probiotic Dosage for Antibiotic-Associated Diarrhea (AAD) and Clostridium difficile-Associated Diarrhea (CDAD)
Research has shown that the dosage of probiotics can significantly impact their efficacy in preventing antibiotic-associated diarrhea (AAD) and Clostridium difficile-associated diarrhea (CDAD). A study involving 255 adult inpatients compared the effects of two different dosages of a proprietary probiotic formula containing Lactobacillus acidophilus and Lactobacillus casei. The study found that taking two probiotic capsules per day, each containing 50 billion colony-forming units (CFU), was more effective in reducing the incidence of AAD and CDAD compared to taking one capsule per day or a placebo. Specifically, the higher dose (100 billion CFU per day) resulted in a lower incidence of AAD (15.5% vs. 28.2%) and CDAD (1.2% vs. 9.4%) compared to the lower dose (50 billion CFU per day).
Probiotic Dosage for Gastrointestinal Symptoms in Healthy Adults
Another study focused on the effects of Bacillus subtilis BS50 on gastrointestinal symptoms in healthy adults. Participants who took 2 billion CFU of Bacillus subtilis BS50 daily for six weeks reported significant improvements in symptoms such as bloating, burping, and flatulence compared to those who took a placebo. The study concluded that 2 billion CFU per day is a well-tolerated and effective dosage for alleviating gas-related gastrointestinal symptoms in healthy adults.
Short-Term Probiotic Intake and Gut Microbiota
A short-term study investigated the impact of consuming 6 billion live probiotic cells daily for one week on the intestinal bifidobacteria and lactobacilli in healthy adults. The results indicated that this dosage was insufficient to significantly modulate the gut microbiota, suggesting that higher or more prolonged dosages might be necessary for noticeable changes in healthy individuals.
Probiotic Dosage for Cardiometabolic Health in Obese Postmenopausal Women
A 12-week study examined the effects of different dosages of a multispecies probiotic supplement on cardiometabolic health in obese postmenopausal women. Participants were divided into three groups: a placebo group, a low-dose group (2.5 billion CFU per day), and a high-dose group (10 billion CFU per day). Both probiotic groups showed significant improvements in various cardiometabolic parameters, but the high-dose group experienced more pronounced benefits, including reductions in lipopolysaccharide levels, waist circumference, fat mass, and several biochemical markers.
Probiotic Dosage for Respiratory and Gastrointestinal Illness in Physically Active Individuals
A study involving 465 healthy, physically active adults assessed the impact of different probiotic strains on respiratory and gastrointestinal illness. Participants were given either 2 billion CFU of Bifidobacterium animalis subsp. lactis Bl-04, 5 billion CFU each of Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07, or a placebo. The group taking Bl-04 had a significantly lower risk of upper respiratory tract infections compared to the placebo group, indicating that 2 billion CFU per day of this specific strain can be beneficial for respiratory health.
Conclusion
The optimal daily dosage of probiotics varies depending on the specific health condition being targeted. For preventing AAD and CDAD, a higher dosage of 100 billion CFU per day appears to be more effective. For alleviating gastrointestinal symptoms in healthy adults, 2 billion CFU per day of Bacillus subtilis BS50 is sufficient. However, short-term intake of 6 billion CFU per day may not significantly impact gut microbiota in healthy individuals. For improving cardiometabolic health in obese postmenopausal women, higher dosages up to 10 billion CFU per day show more significant benefits. Lastly, for reducing respiratory illness in physically active individuals, 2 billion CFU per day of Bifidobacterium animalis subsp. lactis Bl-04 is effective.
Sources and full results
Most relevant research papers on this topic