One of the most researched probiotics, and a low-cost, generally very safe way to support digestion and immune defenses. Its most dependable benefit is reducing the diarrhea antibiotics often cause, with weaker signals for fewer colds and less infant eczema. Effects depend on the exact strain and fade after stopping; serious infections are confined to the critically ill. (Full Review)
| Marker | Target | Why |
|---|---|---|
| hs-CRP | < 1.0 mg/L | Systemic inflammation if anti-inflammatory goal tested |
| Fecal calprotectin | < 50 µg/g | Gut-lining inflammation when digestive symptoms are the focus |
| Complete blood count with differential | Age-appropriate normal | Immune-status safety screen before use |
| Fasting glucose / HbA1c | Glucose 70–90 mg/dL; HbA1c < 5.4% | Optional, only if a metabolic goal is being tested |
Cadence: Optional and symptom-driven; where markers are tracked, reassess at 8–12 weeks, then every 6–12 months