Key points
RepairGut Réparation (Prescription Nature, France) is a powder made of eight groups of ingredients; the table shows the daily serving (manufacturer's page).
| Ingredient | Amount per serving | How it is useful | What human studies showed |
|---|---|---|---|
| Glutamine (L-glutamine + L-alanyl-L-glutamine) | 5 g + 1 g (≈5.7 g glutamine) | an amino acid; it has been studied in increased intestinal permeability | in two RCTs in IBS, 15 g a day reduced symptom severity: in post-infectious IBS with diarrhoea, response in 79.6% versus 5.8% on placebo and intestinal permeability normalised, 54 and 52 people completed the trial (Zhou Q, Gut 2019); as an add-on to a low-FODMAP diet for 6 weeks in 50 patients, the IBS-SSS score fell by more than 45% in 88% versus 60% on placebo (Rastgoo S, Front Nutr 2021) |
| PEA (palmitoylethanolamide), PEAinMAX® with β-caryophyllene 1.6 mg | 340 mg (in 400 mg of PEAinMAX®) | a lipid molecule | together with polydatin: in a pilot 12-week RCT in 54 patients with IBS, 400 mg of PEA a day reduced abdominal pain more than placebo (Cremon C, Aliment Pharmacol Ther 2017) |
| 2'-fucosyllactose (2'-FL) | 1 g | an oligosaccharide of the same type as in human milk | in a mix with LNnT, 10 g a day: an increase in bifidobacteria in IBS |
| Quercetin, TYQUC® with rutin, hesperidin and Sophora japonica 20 mg each | 320 mg (in 400 mg of TYQUC®) | a plant flavonoid | — |
| Vitamin B2 | 1.4 mg (100% of the reference intake, meets the “source of riboflavin” condition) | for normal mucous membranes: “Riboflavin (vitamin B2) contributes to the maintenance of normal mucous membranes” — an EU-authorised claim (Regulation (EU) 432/2012) | — |
| Acacia fibre | 2 g | soluble dietary fibre | — |
| N-acetylglucosamine | 600 mg | an amino sugar | — |
| Chicory extract | 200 mg | a plant extract | — |
Ingredients and the benefit of each
A daily serving is two measuring scoops, 10.6 g. Doses are taken from the manufacturer's page. The product is vegan, gluten-free and lactose-free.
The 5.7 g figure is our calculation: 5 g of L-glutamine plus about 0.67 g of glutamine in 1 g of the dipeptide L-alanyl-L-glutamine (by molar mass).
Glutamine
An amino acid that has been studied in increased intestinal permeability. The most notable result comes from a placebo-controlled RCT in people with diarrhoea-predominant IBS (IBS-D) that began after a gut infection, and with increased intestinal permeability (Zhou Q, Gut 2019). The dose was 5 g three times a day (15 g a day) for 8 weeks. A response (a drop of at least 50 points on the IBS severity score, IBS-SSS) was seen in 79.6% of the glutamine group versus 5.8% on placebo. Increased permeability normalised only in the glutamine group. The trial was completed by 54 people in the glutamine group and 52 in the placebo group.
Quercetin
A plant flavonoid; a serving contains 320 mg. Quercetin increased the electrical resistance of a cell layer — a laboratory measure of barrier tightness — in the human intestinal cell line Caco-2 (Amasheh M, J Nutr 2008; Suzuki T, J Nutr 2009).
PEA (palmitoylethanolamide)
A lipid molecule. In an RCT, patients with IBS received PEA 200 mg together with polydatin 20 mg twice a day, and abdominal pain decreased more than on placebo (see “Key points”).
2'-FL
An oligosaccharide of the same type as in human milk. In IBS, a mix of 2'-FL with another oligosaccharide, LNnT, in a 4:1 ratio was studied: in an RCT, bifidobacteria increased at 10 g a day (Iribarren C, Neurogastroenterol Motil 2020). RepairGut contains 1 g of 2'-FL.
How to take it
RepairGut is a food supplement, not a medicine. According to the manufacturer's page, one measuring scoop of powder (5.3 g) is dissolved in a glass of water and taken in the morning and in the evening, between meals. The recommended duration is 15 days.
In plain words. The manufacturer asks you to take the powder apart from food, but does not require it to be taken on an empty stomach in the morning.
- Take it as the manufacturer directs and do not exceed the dose.
Who should see a doctor first
- If you take medicines regularly or have a chronic illness, discuss the supplement with your doctor first.
According to the manufacturer
The manufacturer states that the product is for adults only and does not recommend it:
- during pregnancy and breastfeeding;
- in prediabetes and diabetes;
- in asthma;
- during treatment with vitamin K antagonists (for example, warfarin);
- in allergy to crustaceans or insects, or known cross-allergy, especially to plants of the Asteraceae (daisy) family;
- on a diet restricted in sodium, potassium or calcium.
Medical caution
- Liver cirrhosis, especially if hepatic encephalopathy has already occurred — only after discussing it with a hepatologist. A glutamine load raises blood ammonia, and a diagnostic test is built on this (Ditisheim S, BMC Gastroenterol 2011; Ampuero J, Liver Int 2020).
- Severe chronic kidney disease — only with a doctor's approval.
- Ciclosporin, digoxin — only with a doctor's approval, because of the quercetin. Quercetin lowered ciclosporin levels in rats (Yu CP, J Agric Food Chem 2011) and sharply raised digoxin levels in pigs (Wang YH, Life Sci 2004); in the pig study the dose was 40 mg/kg, many times more than 320 mg a day. In humans, clinically significant quercetin interactions have been shown for only a few drugs — mainly those broken down by certain liver enzymes or pumped out of cells by a transporter protein (Sulaiman SH, Eur J Clin Pharmacol 2026).
Side effects. Bloating, gas and abdominal pain are possible. In a study in which 5 g a day of a human milk oligosaccharide mix was given, these were the most common adverse events, mostly mild (Palsson OS, Clin Transl Gastroenterol 2020).
- Watch for bloating and gas. If they do not settle within the first few days or get worse, stop taking it and discuss this with your doctor.
- If you develop a rash, itching, swelling or difficulty breathing, stop taking it and seek medical help immediately.
- Blood in the stool, unexplained weight loss, night-time abdominal pain or fever are a reason to get examined first, not to start a supplement.
Bottom line
RepairGut combines in one serving substances that have been studied in IBS and increased intestinal permeability. RCT results in people with IBS exist for glutamine at 15 g a day and for PEA together with polydatin, and vitamin B2 contributes to the maintenance of normal mucous membranes. The course is 15 days on the manufacturer's schedule; with chronic illnesses or regular medicines, talk to a doctor first.
For background, see the broader article on intestinal permeability (leaky gut); the glutamine data are summarised above.
Caveats
- The blend as a whole. All the data above concern the ingredients separately and almost everywhere at other doses or in other forms; among the studies reviewed, there are none of the RepairGut blend itself. So it cannot yet be claimed that RepairGut repairs the gut or treats IBS, nor said whom it will help.
- Glutamine. A daily serving contains about 5.7 g — roughly 38% of the 15 g used in the studies, and the 15-day course is shorter than 6 and 8 weeks; it cannot be claimed that this gives the same result. A meta-analysis of 10 RCTs (352 participants, studies from 1998–2014 in various conditions) found no significant overall effect of glutamine on intestinal permeability (Abbasi F, Amino Acids 2024); the Zhou trial was not included in it, and its authors themselves call for confirmation in larger RCTs. The Rastgoo abstract has an inconsistency: 22 people per group completed the trial, but the proportions are calculated out of 25.
- Quercetin. Its effect on the gut barrier has been studied only in the laboratory, in cells; we found no human RCTs with gut outcomes.
- PEA. In the RCTs found in IBS — only together with polydatin, which RepairGut does not contain; it has not been shown that PEA without polydatin reduces pain. Mast cell counts and other biological markers in biopsies did not change; the authors include an employee of Epitech Group, a PEA manufacturer.
- 2'-FL. 5–10 g a day of a mix with LNnT was studied, whereas RepairGut contains 1 g of 2'-FL alone. Bifidobacteria increased only at 10 g, and symptoms did not differ from placebo; the authors include employees of the company Glycom.
- Acacia fibre, N-acetylglucosamine and chicory extract were not assessed in this guide.
- What may be claimed in the EU. The B2 claim concerns mucous membranes in general and does not mean that RepairGut repairs the gut or the gut barrier. The manufacturer's wording about “healthy intestinal flora” (for chicory) and about glutamine as an “energy source for gut cells” is not an authorised health claim. For chicory, the manufacturer refers to the transitional Article 28 of Regulation (EC) 1924/2006: the EU has not yet decided on such claims, and EFSA has not assessed this phrase. The authorised claim for chicory inulin (stool frequency, from 12 g of native inulin a day, Regulation (EU) 2015/2314) does not apply to 200 mg of extract.
- Probiotics. It contains no live bacteria, even though the manufacturer's website lists the product in its probiotics section.
- Where the contraindications come from. The manufacturer does not explain. Our assumption: crustaceans, asthma, diabetes and warfarin repeat the cautions for glucosamine (Dahmer S, Am Fam Physician 2008) and apparently relate to N-acetylglucosamine, while the Asteraceae point relates to chicory. We found no direct data on N-acetylglucosamine and crustacean allergy; the manufacturer's recommendation is still worth following.
- Level of evidence behind the cautions. Cirrhosis: physiological studies, we found no guidelines; the test uses 20 g, and there are no data on a dose of about 5.7 g in cirrhosis. Kidneys: medical caution, not a conclusion from studies; the indirect basis is the manufacturer's warning about diets restricted in sodium, potassium and calcium. Quercetin: animal experiments and a review of human studies. The oligosaccharide tolerability study was open-label, without a control group; we found no data on the tolerability of the RepairGut blend itself.
“Not shown” does not mean “does not work”: it means the available data do not yet answer the question.
RepairGut is a food supplement, not a medicine, and it does not replace a varied, balanced diet. It is not intended to diagnose, treat or prevent disease and does not replace treatment prescribed by a doctor. This material is for information only.
