saudigastro.com/patients/probiotics-prebiotics-by-condition
This article is educational and does not replace your doctor's advice. Seek urgent care for any red-flag symptoms.
Drug class
Dietary supplement (live microorganisms and fermentable fibres)
Examples
Probiotics: Saccharomyces boulardii, Lactobacillus rhamnosus GG, multi-strain products; prebiotics: inulin, fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS). Brand names vary and are given only as product types, not endorsements.
How it works
Probiotics are live microbes that, in adequate amounts, may give a health benefit; prebiotics are food components (mostly fermentable fibres) that feed gut bacteria. The key scientific point is that effects are strain-specific and condition-specific: a result for one strain in one disease cannot be assumed for another strain or another disease. The AGA 2020 guideline on probiotics in gastrointestinal disorders, the World Gastroenterology Organisation (WGO) guideline on probiotics and prebiotics, and ESPGHAN (European paediatric gastroenterology society) position papers all rate most of the evidence as low or very low quality and give recommendations for named strains only. This page does not repeat the general explanation in our article on probiotics; it focuses on which condition has what level of evidence.
What it treats
- Antibiotic-associated diarrhoea and prevention of C. difficile infection while on antibiotics: GOOD to MODERATE evidence for a few named strains (for example S. boulardii; Lactobacillus rhamnosus GG in children). AGA 2020 gives a conditional, low-certainty suggestion for selected strains and combinations; this is prevention, not treatment
- Active C. difficile infection or repeated infections: LIMITED evidence that probiotics treat it or stop it coming back; treatment relies on proven antibiotics and, for repeated infection, specialist options such as faecal microbiota transplant
- Irritable bowel syndrome (IBS): LIMITED evidence. Some strains may ease bloating or overall symptoms in some people, but AGA 2020 suggests using probiotics for IBS only in the context of clinical trials; UK NICE advises that anyone who chooses to try one should do so for about 4 weeks while monitoring symptoms and stop if there is no benefit
- Pouchitis (inflammation of the surgically made pouch after colectomy): MODERATE evidence for one specific eight-strain combination to help prevent relapse; AGA 2020 gives a conditional suggestion, under specialist care
- Ulcerative colitis and Crohn’s disease: LIMITED to NONE for routine use. AGA 2020 suggests using probiotics for ulcerative colitis or Crohn’s disease only within clinical trials. They are not a substitute for prescribed IBD treatment
- Necrotising enterocolitis (NEC, a serious bowel injury) in premature babies: some strain-specific evidence of benefit (AGA 2020 and ESPGHAN give conditional, strain-specific statements), but this is decided only by the neonatal team; the US FDA warned in 2023 about serious infections in preterm infants and the lack of approved products, so parents should never give it themselves
- Acute gastroenteritis in children: ESPGHAN suggests only certain strains (Lactobacillus rhamnosus GG, S. boulardii) as an add-on to oral rehydration, which remains the main treatment
- Prebiotics (inulin, FOS, GOS): LIMITED evidence for any gut disease; they ferment in the colon and often cause gas and bloating, and may worsen IBS symptoms
How to take it
Because products differ, check the label for the exact strain name (genus, species and strain code), the number of live organisms until the expiry date, and storage instructions; follow the label and your doctor’s or pharmacist’s advice for how much to take. If the condition is one where evidence exists (for example, antibiotic-associated diarrhoea), it is usually started with the antibiotic course. For IBS, set a trial period (about 4 weeks), note your symptoms, and stop if you see no clear benefit; do not keep buying products indefinitely. Take it separately from the antibiotic dose if the label or pharmacist advises. A probiotic is never a replacement for a prescribed treatment. Yoghurt and laban with live cultures are reasonable foods for most healthy people but do not contain the specific strains studied in the trials.
Common side effects
- Gas, bloating or mild abdominal discomfort, especially in the first days
- Loose stools or, less often, constipation
- More gas and bloating with prebiotic fibres such as inulin
- Mild allergic reactions to milk, soy or other ingredients in the product
Serious side effects — call your doctor
Fever, chills, low blood pressure or feeling very unwell while taking a probiotic, especially with a weak immune system, a central venous line, or a serious illness
Rarely the live organisms (bacteria or yeast) enter the bloodstream and cause a serious infection. Stop the product and go to the emergency department urgently; tell them you take a probiotic.
A premature or very sick baby who is feverish, not feeding, has a swollen belly, vomits green fluid or is very drowsy after being given a probiotic
Possible serious infection or bowel injury. Go to the emergency department immediately.
Swelling of the lips, face or throat, wheeze, or widespread rash
Could be a serious allergic reaction. Call emergency services now.
Severe or worsening belly pain, bloody diarrhoea, black stools, or diarrhoea that persists after antibiotics
A probiotic does not explain or treat these. They may be C. difficile infection or another serious problem; see your doctor urgently and do not rely on a probiotic.
Interactions
Who should AVOID probiotics unless their specialist agrees: people with a weakened immune system (for example on high-dose steroids, azathioprine, biologics or chemotherapy, after transplantation, or with advanced HIV), people with a central venous catheter or parenteral nutrition line, people who are critically ill, people with severe acute pancreatitis (a large Dutch trial, PROPATRIA, found more deaths with a multi-species probiotic in predicted severe pancreatitis), people with heart-valve disease or recent bowel surgery with a leak risk, and premature or very sick infants outside the neonatal unit. Antibiotics can kill bacterial probiotics (yeast products such as S. boulardii are not killed by antibiotics, but the yeast is the one linked to bloodstream infection in people with central lines). Pharmacists can advise on spacing from antibiotics. Probiotics sold as supplements are not tested like medicines and contents may differ from the label.
Monitoring
There is no routine blood test. Keep a symptom diary for 2 to 4 weeks (stool frequency, bloating, pain) to judge honestly whether it helps. People with pouchitis or IBD should tell their specialist, who decides on any product and follows disease activity with usual tests.
When and how to stop
Stop if there is no benefit after a fair trial, if symptoms worsen, or if any red-flag symptom appears. Stop and tell your doctor before any planned surgery, chemotherapy or transplant, or if a central line is placed.
Pregnancy & breastfeeding
Probiotic foods are generally fine in pregnancy and breastfeeding. For supplements, there is no strong evidence of harm in healthy women, but ask your doctor or midwife first, especially if you have other conditions.
In the Saudi context
Laban, yoghurt and other fermented dairy are part of the local diet and are a food-first option; choose pasteurised, unsweetened products from trusted sources. Probiotic capsules and powders are widely sold in pharmacies, supermarkets and online, and some are advertised for conditions without evidence. Ask the pharmacist for the strain name, and check that the product is registered with the SFDA. Take extra care during travel (including Umrah and Hajj) if you rely on a refrigerated product.
Questions to ask your doctor
Save this list or print it before your appointment — doctors appreciate prepared patients.
- Is there evidence for a specific probiotic strain in my condition, or is it only a general claim?
- Is it safe for me given my immune system, medicines, central line or recent surgery?
- Should I take it with my antibiotic course, and for how long?
- If my bloating is the main problem, would diet changes or another treatment be a better first step than a probiotic?
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Status: Approved for publication by SGA; individual clinician review is ongoing · Published 24/04/2026
For general education only; it does not replace your doctor’s advice. Individual clinician review of this guide is ongoing. SGA clinician? Review this guide