Protocol · Digestive Health
Acute Gastroenteritis Support Protocol
Lactobacillus reuteri and Probiotics (Multi-Strain) are the core of this stack, with 6 supporting supplements. Each row gives the amount the protocol lists and the grade our evidence database holds for that supplement in Acute Gastroenteritis Support.
We are re-verifying the studies cited on protocol pages; only confirmed citations are shown.
The stack
8 supplements · 1 graded
| Grade | Supplement | Amount listed | Why it’s in the stack | Evidence on file | Shop |
|---|---|---|---|---|---|
| Primary stackThe core of this protocol | |||||
| Lactobacillus reuteri | Amount listed: 10^8–10^10 CFU daily during illness | Specific probiotic strain with strong evidence for reducing duration and severity of acute diarrhea in children and adults
| Not graded yet | ||
| Probiotics (Multi-Strain) | Amount listed: 10–50 billion CFU daily; Saccharomyces boulardii 250–500 mg twice daily | Restore gut microbiome balance, reduce pathogen colonization, and shorten duration of acute diarrhea
| Grade B for Diarrhea Symptoms4 studies · 1,125 people | ||
| Supporting stackListed as additions to the core | |||||
| Saccharomyces boulardii | Amount listed: 250–500 mg twice daily | Probiotic yeast with strong evidence for reducing diarrhea duration; resistant to antibiotics | Not graded yet | ||
| Zinc | Amount listed: Children: 10–20 mg daily for 10–14 days; Adults: 20–40 mg daily | Reduces duration and severity of diarrhea; WHO recommends for children in developing countries | Not graded yet | ||
| Oral Rehydration Salts (ORS) | Amount listed: WHO formula: drink to replace losses (50–100 mL/kg over 4 hours for mild-moderate dehydration) | Replaces fluid and electrolyte losses; cornerstone of gastroenteritis treatment | Not graded yet | ||
| Lactobacillus rhamnosus GG | Amount listed: 10^9–10^10 CFU daily | Well-studied probiotic strain that reduces diarrhea duration, especially in children | Not graded yet | ||
| Ginger | Amount listed: 250–500 mg every 6 hours as needed for nausea | Reduces nausea and vomiting associated with gastroenteritis | Not graded yet | ||
| Glutamine | Amount listed: 5–10 g daily during illness | Supports intestinal barrier function and enterocyte recovery during gut infections | Not graded yet | ||
Shop the evidence-backed picks
Support alongside medical care. These supplements are not a treatment for Acute Gastroenteritis. If you are being treated for it, talk to your clinician before adding one: supplements can interact with medicines.
The collection holds the supplements we grade A or B for its theme, in third-party tested products where the catalog has them. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.
Or shop one supplement
The supplement in this protocol graded A or B. Each opens third-party tested products, matched to the dose above where we can.
- Grade B
We earn from purchases made in our Fullscript store, and links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Full disclosure
How this protocol works
In plain language
Acute gastroenteritis is inflammation of the stomach and intestines, usually caused by viral infections (rotavirus, norovirus), bacterial infections (Salmonella, E. coli, Campylobacter), or occasionally parasites. Symptoms include diarrhea, vomiting, nausea, abdominal cramps, and sometimes fever. Most cases are self-limiting and resolve within a few days, but the main danger is dehydration, especially in young children, elderly, and immunocompromised individuals.
CRITICAL: The primary treatment for gastroenteritis is rehydration. Seek medical attention for: bloody diarrhea, high fever, severe abdominal pain, signs of dehydration (decreased urination, dry mouth, dizziness), symptoms lasting more than 3 days, or symptoms in infants, elderly, or immunocompromised individuals.
- Oral Rehydration Salts (ORS) are the cornerstone of gastroenteritis treatment. The WHO-formula contains the optimal ratio of glucose, sodium, and other electrolytes to maximize water absorption even during diarrhea. This simple intervention saves millions of lives annually, particularly in developing countries.
- Lactobacillus reuteri is one of the best-studied probiotics for acute diarrhea. It colonizes the gut rapidly and produces antimicrobial substances that inhibit pathogens. Multiple meta-analyses show it significantly reduces diarrhea duration by about 1 day.
- Saccharomyces boulardii is a probiotic yeast (not a bacteria) with strong evidence for acute diarrhea. Because it's a yeast, it's resistant to antibiotics, making it especially useful when gastroenteritis occurs during antibiotic treatment or when antibiotic-associated diarrhea is a concern.
- Lactobacillus rhamnosus GG is another well-studied probiotic strain with consistent evidence for reducing diarrhea duration in children. It works by strengthening the gut barrier, competing with pathogens, and modulating immune responses.
- Zinc is recommended by the WHO for children with acute diarrhea, particularly in developing countries where zinc deficiency is common. Even in well-nourished populations, zinc supplementation can reduce diarrhea duration and severity. It supports immune function and helps maintain gut barrier integrity.
- Ginger is effective for the nausea and vomiting that often accompany gastroenteritis. It works through serotonin receptor antagonism and effects on gastric motility.
- Glutamine is the primary fuel for intestinal cells (enterocytes). During gut infections, glutamine demand increases. Supplementation may help support gut barrier repair and recovery.
Expected timeline: Probiotics typically reduce diarrhea duration by 1-2 days. Effects begin within 24-48 hours. Most acute gastroenteritis resolves within 3-7 days. Continue probiotics for several days after symptoms resolve to help restore normal gut flora.