Other
CoQ10
Coenzyme Q10, a naturally occurring antioxidant involved in cellular energy production, commonly used for heart health and mitochondrial support.
Moderate Evidence
Moderate Evidence Probiotic
Probiotics
Live beneficial bacteria that support gut microbiome health, digestion, and immune function.
Updated February 20, 2026This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication regimen.
Benefits & Uses
- Antibiotic-associated diarrhea (AAD): Research (multiple meta-analyses) indicates probiotics may reduce risk of AAD and Clostridioides difficile–associated diarrhea; benefit is strain- and dose-dependent (moderate-to-strong evidence).
- Irritable bowel syndrome (IBS): Systematic reviews suggest certain strains/blends can modestly improve global IBS symptoms, bloating, and stool consistency (moderate evidence; heterogeneous results).
- Acute infectious diarrhea: Some strains (e.g., Lactobacillus rhamnosus GG, Saccharomyces boulardii) may shorten duration, especially in children (moderate evidence).
- Ulcerative colitis and pouchitis (adjunct/maintenance): Specific high-dose multi-strain products (e.g., VSL#3/Visbiome) and E. coli Nissle 1917 show benefit for maintaining remission and preventing pouchitis recurrence (moderate evidence, strain-specific).
- Helicobacter pylori therapy adjunct: Adding probiotics to eradication regimens may modestly increase eradication rates and reduce GI side effects (moderate evidence; strain-specific).
- Upper respiratory tract infections: Some meta-analyses report fewer and shorter URTI episodes with regular probiotic use (modest effect; moderate evidence).
- Infant/Neonatal care: In preterm infants, certain probiotics reduce necrotizing enterocolitis and all-cause mortality (moderate-to-strong evidence, product- and setting-specific; requires medical oversight).
- Lactose intolerance: Some strains may improve lactose digestion and reduce symptoms (emerging-to-moderate evidence).
Side Effects & Precautions
- Common (generally mild, dose-dependent): gas, bloating, abdominal discomfort, changes in stool frequency/consistency; typically transient during the first days of use.
- Less common: headache, nausea, increased thirst.
- Rare but serious: bloodstream infections (bacteremia from lactobacilli; fungemia with Saccharomyces boulardii), sepsis, endocarditis in predisposed individuals (very rare; primarily in immunocompromised, critically ill, presence of central venous catheters, or severe underlying disease). Case reports/series document these events.
- Specific risks: D-lactic acidosis (confusion, ataxia) in short bowel syndrome with D-lactate–producing strains; fungemia risk with S. boulardii especially in ICU/central line settings.
- Allergy considerations: Trace milk/soy allergens may be present from growth media; hypersensitivity reactions are rare.
Dosage & Administration
- Typical supplemental doses in studies range from 1×10^9 to 1×10^11 CFU/day, taken once or divided. Effective doses are strain- and condition-specific.
- For AAD prevention, trials often used Lactobacillus rhamnosus GG or Saccharomyces boulardii with total daily doses around 10^9–10^10 CFU (or 250–500 mg S. boulardii) during antibiotic therapy and for up to 1–2 weeks after.
- For IBS, multi-strain blends are commonly studied at 10–100 billion CFU/day for 4–8 weeks.
- For ulcerative colitis/pouchitis maintenance, very high-dose multi-strain products (e.g., 10^11–10^12 CFU/day) have been used.
- For H. pylori adjunct therapy, daily doses typically 10^9–10^10 CFU with specific Lactobacillus/Bifidobacterium strains during eradication.
- Administration notes: Take separate from antibiotics by at least 2–3 hours to reduce inactivation. Optimal strain, dose, and duration vary by individual and indication.
Contraindications
- Immunocompromised states (e.g., neutropenia, post-transplant, advanced HIV/AIDS, hematologic malignancy) due to risk of systemic infection; use only under medical supervision or avoid.
- Presence of central venous catheters or ICU care: increased risk of probiotic translocation/contamination leading to bacteremia/fungemia; avoid, especially S. boulardii.
- Severe acute pancreatitis: a large RCT reported increased mortality with multispecies probiotics; avoid.
- Critical illness, uncontrolled severe comorbidities, valvular heart disease/prosthetic valves: avoid or use only with medical supervision due to rare risk of endocarditis/bacteremia.
- Short bowel syndrome or history of D-lactic acidosis: avoid D-lactate–producing strains; specialist guidance recommended.
- Pregnancy/breastfeeding: Generally considered well tolerated in healthy individuals with no clear increase in adverse outcomes in meta-analyses; however, product quality varies—discuss with a clinician before use.
- Perioperative: Consider stopping 1–2 weeks before major surgery or if central lines will be used, unless specifically recommended by the surgical team.
Known Interactions
| Substance | Type | Severity | Description |
|---|---|---|---|
| Broad-spectrum antibiotics (e.g., amoxicillin-clavulanate, ciprofloxacin) | caution | moderate | Antibiotics can inactivate/kill probiotic organisms, reducing viability and effectiveness; separate dosing by 2–3 hours. Despite this, co-use is often studied to reduce antibiotic-associated diarrhea. |
| Antifungals (e.g., fluconazole, nystatin) | antagonistic | moderate | Systemic or oral antifungals can kill Saccharomyces boulardii, negating its effects; avoid concurrent use of S. boulardii with antifungals. |
| Immunosuppressants (e.g., tacrolimus, cyclosporine, high-dose corticosteroids, anti-TNF biologics) | caution | severe | Reduced host defenses increase risk of systemic infection from live microbes; probiotics should generally be avoided or used only with close medical supervision. |
| Warfarin | caution | moderate | Some gut bacteria produce vitamin K (menaquinones), which could theoretically reduce INR; clinical significance appears limited but monitoring is prudent when starting/stopping probiotics. |
| Vancomycin or metronidazole (for C. difficile infection) | synergistic | moderate | Adjunct probiotics may reduce diarrhea severity or recurrence and antibiotic side effects, but benefits are strain-specific and should be weighed against infection risk in high-risk patients. |
Sources
- Probiotics for preventing Clostridium difficile–associated diarrhea in adults and children (Cochrane Review) (meta-analysis) , 2017
- Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis (JAMA) (meta-analysis) , 2012
- Efficacy of probiotics in irritable bowel syndrome: systematic review and meta-analysis (Am J Gastroenterol) (meta-analysis) , 2014
- Probiotics for prevention of necrotizing enterocolitis in preterm infants (Cochrane Review) (meta-analysis) , 2020
- Probiotic prophylaxis in predicted severe acute pancreatitis (PROPATRIA Trial, N Engl J Med) (rct) , 2008
- Probiotics for induction and maintenance of remission in ulcerative colitis and prevention of pouchitis (systematic review) (review) , 2019
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Health Disclaimer
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication regimen.