Is apple cider vinegar good for digestion and gut health?

As far as we could find, nobody has tested it. We found no randomized trial and no systematic review of apple cider vinegar, or of vinegar in general, for indigestion, reflux, bloating, bowel habit or gut bacteria. The one thing vinegar measurably does to digestion is slow how fast the stomach empties. In 10 people with type 1 diabetes whose stomachs already emptied too slowly, a meal with apple cider vinegar emptied at a median of 17 percent against 27 percent with water.

Unsettled. This is unsettled because it is untested, which is different from tested and failed. The benefits sold online, better digestion, less bloating and a healthier gut, have no trial behind them that we could find. Web pages describing such trials did not lead to any record in PubMed or a trial registry.

What the trials found

Slower stomach emptying

In a randomized crossover meal test in 10 healthy adults in Lund, Sweden, vinegar added to a white bread meal lowered blood sugar and insulin responses. Judged by a marker drug in the blood, the authors concluded the mechanism is probably delayed stomach emptying. That was a single meal, and the marker is indirect.

The gastroparesis study measured emptying directly in 10 people with type 1 diabetes. Emptying was slower after the vinegar meal than after the reference meal, and it slowed in 8 of the 10. The meals were not randomized and the participants were not blinded, which the authors list as their own limitation. For people with gastroparesis, slower emptying is the problem, so this counts against vinegar for them.

Nausea

In 16 healthy young adults, drinking vinegar with breakfast reduced appetite and food intake, and nausea ratings rose with it. Tasting vinegar without swallowing it had no effect. The authors concluded the drop in appetite was largely due to poor tolerability, with vinegar causing feelings of nausea. These short, single-meal experiments are the only ones here that measured how people felt after vinegar, and what they found was nausea.

What the reviews cover

A 2026 umbrella review gathered 10 meta-analyses of vinegar covering 38 trials. They looked at blood sugar, cholesterol, weight and blood pressure, and none assessed a digestive outcome. The synthesized evidence for vinegar is cardiometabolic only.

The closest thing to gut data is a survey of 546 university students. How often they ate yogurt, kefir, vinegar, cheese and pickles differed by gut symptom scores (p below 0.05). The abstract does not say in which direction vinegar went, 44.3 percent of the students never ate it, and the authors' conclusion names yogurt, cheese, pickles and kefir, not vinegar. A cross-sectional survey cannot show cause in any case.

Who should be careful

Not for everyone. If you have type 1 diabetes or diagnosed gastroparesis, apple cider vinegar with meals can slow an already slow stomach further, which also changes when food reaches the blood relative to an insulin dose. That is a conversation with the person who manages your diabetes.

Tablets carry their own risk. After an apple cider vinegar tablet injured one person's esophagus, researchers tested 8 tablet brands and found considerable variation in tablet size, acidity, acid content and label claims. That is a single injury, the product data date from 2005, and we could not read the details of the case.

Teeth are the other concern. In a UK case-control study of 309 children, those with dental erosion ate vinegar and fruit more often than children without it. That is an association in children, for any vinegar, but it fits the usual advice to dilute acidic drinks and not hold them in the mouth.

What expert bodies say

The European Union refused a set of apple cider vinegar digestion claims, including that it helps improve digestion, keeps bowel movements normal and promotes intestinal activity. No apple cider vinegar claim was authorized in the register. A refusal means the evidence did not meet the bar, and it is not a finding of harm. We found no other expert body that has taken a position on vinegar for digestion.

How we searched

What would change this answer

• A randomized trial of apple cider vinegar against a placebo drink in people with indigestion or bloating, measuring the symptoms people actually buy it for.
• A trial in people with reflux, which shop pages promote it for and nobody has tested.
• A human trial measuring gut bacteria before and after regular vinegar. The microbiome studies we found were in animals.

What apple cider vinegar contains and what else it has been tested for is on the apple cider vinegar page.

Sources

1. ev-acvd-01 · Observational data · non-randomized, investigator-blinded crossover pilot study · n = 10
   Gastric emptying rates after the meal including vinegar were significantly lower (p < 0.05) than after the reference meal.
   
   Who: ten patients with type 1 diabetes and diagnosed diabetic gastroparesis, Malmo, Sweden
   Effect: median gastric emptying rate 17% with vinegar vs 27% with water reference meal (p < 0.05); reduced in 8 of 10 patients
   Certainty: Meals not randomized and subjects not blinded (authors' own limitation); tiny sample. Slower emptying is a drawback for gastroparesis and insulin timing.
   BMC Gastroenterology, 2007, 7:46 (Hlebowicz et al.) · checked 2026-10-06 · we read the fulltext
2. ev-acvd-02 · Randomized controlled trial(s) · randomized-order crossover meal test · n = 10
   As judged from lowered paracetamol levels after the test meal with vinegar, the mechanism is probably a delayed gastric emptying rate.
   
   Who: ten healthy volunteers, seven women and three men, aged 22-51 years, Lund, Sweden
   Effect: glycemic index 64 and insulinemic index 65 vs white bread reference (100); lower paracetamol levels indicating delayed gastric emptying
   Certainty: Single meal, indirect marker of emptying (paracetamol absorption); white wine vinegar type not specified in the abstract.
   European Journal of Clinical Nutrition, 1998, 52(5):368-371 (Liljeberg and Bjorck) · checked 2026-10-06 · we read the abstract
3. ev-acvd-03 · Meta-analysis or systematic review · umbrella review of meta-analyses of randomized controlled trials · n = 38 primary studies
   Vinegar is a natural dietary product that has been proposed to exert beneficial effects on cardiometabolic health, including glycemic regulation, lipid metabolism, blood pressure control, and weight management.
   
   Who: adults in randomized trials pooled in 10 meta-analyses of vinegar consumption
   Effect: fasting glucose -9.40 mg/dL, HbA1c -0.70%, body weight -2.3 lb (-1.06 kg), systolic BP -2.94 mmHg; no gut, reflux or bowel outcome among those assessed
   Certainty: Shows the gap: the synthesized trial evidence for vinegar is cardiometabolic only.
   Food Science & Nutrition, 2026, 14(5):e71849 (Shahmohammadi et al.) · checked 2026-10-06 · we read the abstract
4. ev-acvd-04 · Randomized controlled trial(s) · randomized crossover acute feeding study · n = 16
   These studies indicate that vinegar ingestion enhances satiety whereas orosensory stimulation alone does not, and that these effects are largely due to poor tolerability following ingestion invoking feelings of nausea.
   
   Who: healthy, young, normal weight unrestrained eaters
   Effect: lower appetite and food intake with significantly higher nausea ratings; tasting without swallowing had no effect (14 adults)
   Certainty: Acute only; nausea is the most consistent gut effect reported.
   Int J Obes (Lond), 2014 · checked 2026-10-06 · we read the abstract
5. ev-acvd-05 · Laboratory or animal data · case report with laboratory product analysis · n = 8 products
   After an adverse event was reported to the authors, eight apple cider vinegar tablet products were tested for pH, component acid content, and microbial growth.
   
   Who: one adverse event case and eight commercial apple cider vinegar tablet products
   Effect: considerable variability between brands in tablet size, pH, acid content and label claims; doubt whether ACV was an ingredient
   Certainty: Single injury; product data from 2005. Injury described in the title, details in full text (not obtained).
   Journal of the American Dietetic Association, 2005, 105(7):1141-4 (Hill et al.) · checked 2026-10-06 · we read the abstract
6. ev-acvd-06 · Observational data · case-control study · n = 309
   Fruit and vinegar consumption was higher in the erosion group, as was the taking of vitamin C supplements.
   
   Who: 309 age and gender matched children (erosion, caries-active, caries-free), UK
   Effect: vinegar and fruit consumption higher in the erosion group; acidic drinks and swishing habits also more common
   Certainty: Association only, children, any vinegar; supports advice to dilute and not hold acidic drinks in the mouth.
   ASDC J Dent Child, 2000 · checked 2026-10-06 · we read the abstract
7. ev-acvd-07 · Observational data · cross-sectional survey · n = 546
   Significant differences were found between the frequency of yogurt, kefir, vinegar, cheese, pickle consumption, and gastrointestinal symptoms (p < 0.05).
   
   Who: 546 university students
   Effect: significant differences in gastrointestinal symptoms by frequency of yogurt, kefir, vinegar, cheese and pickle intake (p < 0.05); direction for vinegar not given in abstract
   Certainty: Cross-sectional, self-report; 44.3% never ate vinegar; cannot show cause; the authors' conclusion names yogurt, cheese, pickles and kefir, not vinegar.
   PeerJ, 2025 · checked 2026-10-06 · we read the abstract
8. ev-acvd-08 · Position of an expert body · entry in the EU Register on nutrition and health claims, non-authorized list · n = —
   POL-HC-6625 Apple cider vinegar 1. Helps improve digestion 2. Helps maintain normal bowel movement 3. Normalizes bowel movement 4. Promotes intestinal activity 5. Promotes/contributes to bowel regularity Non-authorised
   
   Who: EU food labeling
   Effect: claim POL-HC-6625 (improve digestion, normal bowel movement, intestinal activity, bowel regularity), status Non-authorized; no ACV claim authorized in the register snapshot
   Certainty: Refused means the evidence did not meet the bar, not that harm or lack of effect was shown.
   EU Register on nutrition and health claims (European Commission) · checked 2026-10-06 · we read the dataset