Probiotics in Medical Practice

Indications with Solid Evidence

The American Gastroenterological Association recommends the use of probiotics, specifically Lactobacillus rhamnosus at 5-10 billion CFU/day, to reduce the risk of antibiotic-associated diarrhea with low probability of adverse events 4
The use of Saccharomyces boulardii at 1g or 3×10¹⁰ CFU/day reduces the risk of Clostridioides difficile infection by 59% (RR 0.41; 95% CI 0.22-0.79) 5
The combination of two strains (Lactobacillus acidophilus CL1285 + Lactobacillus casei LBC80R) reduces the risk by 78% (RR 0.22; 95% CI 0.11-0.42) 5
Probiotics in combination with standard triple therapy improve Helicobacter pylori eradication rates, with combinations containing Lactobacillus acidophilus and Bifidobacterium animalis being more effective than single strains 6
Probiotics also reduce the side effects of antibiotic therapy, particularly antibiotic-associated diarrhea 6
The European Society of Gastroenterology recommends the use of probiotics to reduce symptoms in adults with irritable bowel syndrome 6
The American Heart Association suggests that probiotic intake improves systolic and diastolic blood pressure, especially if baseline blood pressure is ≥130/85 mmHg, with a treatment duration of at least 8 weeks, using multiple strains and a daily consumption of 10¹¹ or more CFU 6

For ulcerative colitis, recent evidence (2014) suggests that probiotics may be useful both in combination with specific therapy and in the maintenance phase 6
For Crohn's disease, there is insufficient evidence to demonstrate that probiotics help maintain remission in adults and children 6

Probiotics modulate the intestinal microbiota by increasing beneficial bacteria and suppressing the growth of harmful microorganisms 1, 2
Probiotics improve intestinal barrier function by strengthening the integrity of the intestinal epithelium 1
Probiotics produce beneficial metabolites, such as short-chain fatty acids, vitamins, and other metabolites that promote intestinal health 2, 7
Probiotics modulate the immune system by stimulating the production of beneficial compounds, supporting the development of immune cells, and promoting a balanced immune response 2, 7
Probiotics reduce intestinal inflammation by decreasing inflammatory markers in the gastrointestinal tract 1, 2

Probiotics are contraindicated in immunocompromised patients due to the risk of bacteremia or fungemia, particularly in patients with neutropenia, severe debilitation, central venous catheters, or underlying severe disease 4, 5, 8
The use of probiotics should be avoided in patients with compromised immune systems, such as those with HIV or undergoing chemotherapy 8

The majority of evidence is classified as low to moderate due to heterogeneity in study populations, probiotic strains, and outcome measures 5, 6
There is potential publication bias with many registered trials lacking subsequent publications 5

To maximize benefits and minimize risks, select products with strains supported by high-quality clinical trials for the target indication 3, 4
Verify that the product guarantees bacterial viability until the end of its shelf life 8
Use adequate doses according to evidence (generally ≥10⁹-10¹¹ CFU/day) 6, 4
Avoid use in vulnerable or immunocompromised patients 8, 4, 5