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Head-to-head evidence comparison — which supplement is right for you?
Probiotics vs Selenium: Probiotics has the stronger overall evidence (9 vs 6.5/10); they're alternatives for reduce inflammation — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Probiotics wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
29 of 38 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
27 of 34 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (2)
Outcomes where both Probiotics and Selenium have evidence — compare verdict strength side-by-side.
10-20 billion CFU
With or without food (strain-dependent), Same time daily for consistency
Capsules with multiple strains
100-200mcg
With food
Selenomethionine (best absorbed)
2-4 weeks
4-8 weeks
4-8 weeks
First 1-2 weeks
4-8 weeks
4-8 weeks
Preventive Effect of Probiotics on Oral Mucositis Induced by Cancer Treatment: A Systematic Review and Meta-Analysis
International journal of molecular sciences (2022) · Meta analysis · n=708
Three trials using Lactobacilli-based probiotics reported that the incidence of oral mucositis in the probiotic group was significantly low (risk ratio [RR] = 0.84, 95% confidence interval [CI] = 0.77−0.93, p = 0.0004).
Probiotics for treating acute infectious diarrhoea
The Cochrane database of systematic reviews (2020) · Meta analysis · n=12127
Effect size was similar in the sensitivity analysis and marked heterogeneity persisted.
Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children
The Cochrane database of systematic reviews (2017) · Meta analysis · n=9955
A complete case analysis (i.e. participants who completed the study) among trials investigating CDAD (31 trials, 8672 participants) suggests that probiotics reduce the risk of CDAD by 60%.
Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials
The American journal of clinical nutrition (2020) · Meta analysis · n=9423
However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent.
Selenium for preventing cancer
The Cochrane database of systematic reviews (2018) · Meta analysis · n=27232
For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence).
Selenium and prostate cancer: systematic review and meta-analysis
The American journal of clinical nutrition (2012) · Meta analysis · n=13254
Three high-quality studies included in the meta-analysis of toenail selenium and cancer risk indicated a reduction in prostate cancer risk (estimated RR: 0.29; 95% CI: 0.14, 0.61) with a toenail selenium concentration between 0.85 and 0.94 μg/g.
Based on meta-analyses showing benefits for IBS and digestive symptoms. Effect sizes varied considerably between studies with low to very low certainty of evidence. Initial GI symptoms common when starting but typically resolve within 1-2 weeks.
Based on Cochrane systematic review showing moderate-certainty evidence for TPO antibody reduction. Effects on thyroid hormone levels (TSH, T4, T3) were inconsistent across studies.
AI-estimated from published studies. Interpret as directional guidance.
Probiotics has a higher evidence score (9/10 vs 6.5/10) and wins in 2 of 3 categories.
For reduce inflammation, Probiotics has a higher relevance score (95 vs 52).
No known interactions between Probiotics and Selenium have been documented in our database. However, always consult a healthcare provider before combining supplements.
The honest tier list — proven staples vs situational vs mostly marketing. The hub the other guides feed into.
On Ozempic/Wegovy/Mounjaro? What actually helps — muscle preservation, GI relief, nutrient gaps (no upsell).
Saffron, EPA omega-3, SAMe have real adjunct evidence — but these aren’t a substitute for care, and some interact dangerously.
Probiotics vs prebiotics vs synbiotics, the CFU myth, and what actually helps bloating.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.