Gram Research analysis of a 2026 study finds that moderate drinking does not change how closely adults with prediabetes follow a Mediterranean diet, but men who drank moderately had higher levels of Akkermansia muciniphila, a gut bacterium linked to metabolic health. Among women, drinkers ate more sugar than non-drinkers.
According to Gram Research analysis, moderate drinking does not appear to change how closely adults with prediabetes follow a Mediterranean diet, but its links to gut bacteria may differ between men and women. Prediabetes means blood sugar is higher than normal but not yet high enough to be diabetes. Researchers in Spain studied 67 adults aged 40 to 70 with prediabetes. Participants were grouped as non-drinkers, beer drinkers, or wine and spirits drinkers, based on repeated three-day food diaries. Among men, moderate drinkers ate more fruit and had higher levels of Akkermansia muciniphila, a gut bacterium linked to metabolic health. Among women, drinkers ate more sugar than non-drinkers. The study cannot prove cause and effect, and it does not show that alcohol is healthy. The authors say these sex differences should be considered before making general claims about the benefits or harms of drinking.
Key Statistics
A 2026 study of 67 adults with prediabetes, published in Nutricion Hospitalaria, found that men who drank alcohol in moderation had higher levels of Akkermansia muciniphila, a gut bacterium linked to metabolic health.
The same 2026 study found that women who drank alcohol consumed more sugar than women who did not drink, while overall Mediterranean diet adherence did not differ between drinkers and non-drinkers.
Researchers in this 2026 study collected three-day food diaries three separate times from each of 67 participants aged 40 to 70 years to estimate their usual eating habits.
The Quick Take
- What they studied: The researchers wanted to know whether drinking alcohol in moderation is linked to diet quality and to the types of bacteria living in the gut of people with prediabetes, and whether beer, wine, or spirits make a difference.
- Who participated: 67 adults aged 40 to 70 living in Spain who had prediabetes. There were 30 men and 37 women. Participants were grouped as people who did not drink, beer drinkers, or wine and spirits drinkers.
- Key finding: Moderate drinking was not linked to a different Mediterranean diet score overall. However, men who drank moderately ate more fruit and had higher levels of Akkermansia muciniphila, a gut bacterium associated with healthy metabolism. Women who drank ate more sugar than women who did not drink. Because the study was small and observational, these links are associations, not proof of cause.
- What it means for you: If you already drink alcohol, keeping it moderate is probably less important for your gut than your overall eating pattern. Do not start drinking to improve your health. Alcohol carries risks, and anyone with prediabetes should talk with a doctor or dietitian about what fits their situation.
The Research Details
This study looked at a group of adults with prediabetes at one point in time and compared how they drank with what they ate and what bacteria lived in their guts. This kind of study is called cross-sectional. It is useful for spotting patterns, but it cannot show that one thing caused another.
Each participant completed a three-day food diary three separate times. This helped the researchers estimate typical eating habits, including how closely people followed a Mediterranean style of eating, which emphasizes vegetables, fruit, whole grains, olive oil, and fish. Participants were sorted into groups based on their drinking habits: people who abstained, beer drinkers, and wine or spirits drinkers.
The team measured gut bacteria from stool samples using a lab method called qPCR, which counts specific bacteria. They then used statistical models that adjusted for factors such as age, sex, and health measures, so the groups could be compared more fairly.
Using repeated food diaries gives a more reliable picture of usual eating than a single snapshot. Measuring specific gut bacteria allows researchers to look at particular microbes that have been linked to metabolic health. Adjusting for age, sex, and clinical factors helps reduce the chance that differences come from other causes. Together, these choices make the findings more meaningful, even though the study is small.
This study was published in a peer-reviewed journal, which means outside experts checked it before publication. Its main strengths are the repeated diet records and the detailed gut bacteria measurements. However, it included only 67 people from one country, so results may not apply to everyone. The design also cannot prove that alcohol changed the bacteria or diet. Diet records rely on people remembering and reporting accurately, which can introduce errors. The available summary does not list every exact statistic, so readers should view the specific percentages with caution until they read the full paper.
What the Results Show
The main question was whether people who drank alcohol followed a healthier overall eating pattern than people who did not. The answer appears to be no. Based on the Mediterranean diet scores, drinkers and non-drinkers ate in similar ways overall. This suggests that moderate drinking was not clearly tied to a better or worse overall diet in this group.
The picture changed when the researchers looked at men and women separately. Among men, moderate alcohol intake was linked to a healthier diet in one specific way: men who drank ate more fruit. These men also had higher levels of Akkermansia muciniphila in their gut. This bacterium has been studied for its possible role in healthy blood sugar and metabolism, though scientists are still working out how it works.
Among women, the pattern was different. Women who drank alcohol consumed more sugar than women who did not drink. This finding suggests that the relationship between drinking and diet may not be the same for everyone, and that sex may matter.
Taken together, the results suggest that alcohol’s association with diet and gut bacteria depends on sex. The researchers caution that these are patterns in a small group, not proof that drinking changes gut health or that drinking is safe.
The study also compared beer drinkers with wine and spirits drinkers. These comparisons help show that the type of drink may matter less than whether a person drinks at all and how their overall diet looks. The authors noted that the results point to the need for more research before making firm recommendations. Some of the differences by sex were significant enough to highlight, but readers should treat them as early signals rather than settled facts.
Some researchers have suggested that beer and wine contain plant compounds called polyphenols that may reduce inflammation, and that moderate drinking can be part of a Mediterranean style of eating. This study adds a more nuanced view: in this group, the benefits were not clearly visible across the board, and any links appeared to depend on sex. Other studies have linked Akkermansia muciniphila to healthier metabolism, and this study fits that pattern, but it does not prove the bacterium caused any health benefit.
The study included only 67 adults from Spain, so the results may not apply to people in other countries, ages, or health conditions. Because it looked at a single point in time, it cannot show that drinking caused changes in diet or gut bacteria. Food diaries depend on memory and honest reporting, and small errors can affect results. Alcohol intake was based on how people reported their drinking, which may not be exact. The sample was also split into smaller groups by sex and drink type, which makes it harder to draw firm conclusions. Finally, gut bacteria can change with many factors, including medications, other foods, and lifestyle, and not all of these may have been captured.
The Bottom Line
Research does not support starting to drink alcohol to improve gut health or blood sugar. Confidence in the current findings is low to moderate because the study is small and observational. The strongest evidence for people with prediabetes still favors a balanced eating pattern, regular physical activity, and maintaining a healthy weight. If you choose to drink, keeping it moderate is the usual guidance, but this study alone does not show that moderate drinking is beneficial. Many health authorities advise that less alcohol is safer for everyone.
People with prediabetes, dietitians, and clinicians who work on blood sugar and metabolic health may find this research useful. It may also interest researchers studying gut bacteria and sex differences in health. People who do not drink should not feel pressured to start. Anyone who is pregnant, has liver disease, takes medications that interact with alcohol, or has a history of alcohol use disorder should avoid drinking and speak with a healthcare provider. People with diabetes should also discuss alcohol with their doctor, since it can affect blood sugar.
Changes in gut bacteria can occur within weeks of changing diet, but how these shifts affect long-term health takes months to years to measure. This study did not track people over time, so it cannot tell you how quickly any benefit or harm might appear. For prediabetes, meaningful improvements in blood sugar usually take several months of consistent eating, activity, and weight management, and a doctor can check progress with routine blood tests.
Frequently Asked Questions
Is moderate alcohol good for gut bacteria in people with prediabetes?
A 2026 study of 67 adults with prediabetes found the effects depended on sex. Men who drank moderately had higher levels of Akkermansia muciniphila, a beneficial gut bacterium, but the study cannot prove alcohol caused this change, so drinking is not recommended for gut health.
Does drinking alcohol change how well you follow a Mediterranean diet?
In a 2026 study of 67 adults with prediabetes, moderate drinkers and non-drinkers followed the Mediterranean diet about equally well overall. Men who drank ate more fruit, while women who drank consumed more sugar than women who abstained.
Should people with prediabetes drink beer or wine for their health?
Current research does not support starting to drink alcohol for health benefits. This study was small and observational. Prediabetes care centers on diet, physical activity, and weight management, and a doctor can advise whether any alcohol fits your personal health situation.
What is Akkermansia muciniphila?
Akkermansia muciniphila is a gut bacterium that lives in the intestinal lining and has been linked to healthy metabolism in several studies. In a 2026 study of 67 adults, men who drank moderately had higher levels of it, but researchers cannot yet say whether it directly improves blood sugar.
Want to Apply This Research?
- Log every alcoholic drink, including the type and the serving size, and record your daily servings of fruit and grams of added sugar if your app can estimate them. Review the weekly totals to see how drinking days relate to fruit intake and sugar intake. Track fasting blood sugar or readings from a home glucose meter if your doctor has recommended them.
- Set a weekly alcohol limit that matches your doctor’s advice and use the app to log every drink against it. On drinking days, pair alcohol with a fruit-rich meal and try to limit sugary mixers or sweet wines. Use the app to set a reminder to add at least two servings of fruit each day, and to swap sugary drinks for water or unsweetened tea.
- Review your drinking log, fruit intake, and added sugar intake every month. Each quarter, check whether your blood sugar readings or lab results are moving in the direction your doctor expects. Share trends with your healthcare provider rather than relying on the app alone, and update your goals whenever your health status or medications change.
This article summarizes a single small observational study and is for general educational purposes only. It is not medical advice and does not establish that alcohol is safe or beneficial for anyone. Alcohol can affect blood sugar, medications, and many health conditions. Consult a doctor, registered dietitian, or other qualified healthcare provider before changing your drinking habits, especially if you have prediabetes, diabetes, liver disease, or are pregnant or planning pregnancy.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.