Ramadan Fasting Increased a Key Gut-Lining Bacteria by the End of the Month: What the Research Shows

Ramadan Fasting Increased a Key Gut-Lining Bacteria by the End of the Month: What the Research Shows

Medical disclaimer: This article summarises published research for informational purposes only. It is not medical advice and is not a substitute for guidance from a qualified health professional. Always consult your doctor before starting any fasting protocol, especially if you have an existing health condition or take medication.

Study at a Glance

What This Study Looked At

Researchers wanted to know whether a full month of dawn-to-dusk intermittent fasting — the pattern followed during Ramadan — changes the composition of the human gut microbiome, and specifically whether it affects bacteria linked to gut barrier integrity. This connects directly to broader questions about how intermittent fasting affects gut health and how fasting gives the digestive system a period of rest. The team focused on stool samples taken before and after the fasting month in healthy volunteers.

Who Was Studied

Participant profile: Healthy adult volunteers with no reported chronic gastrointestinal disease, recruited to observe the standard Ramadan fasting pattern.

How the fasting protocol worked in this study: Participants abstained from all food and drink from dawn until sunset each day for the duration of Ramadan, then ate normally during the night-time hours — a daily fasting window of roughly 14–16 hours depending on the time of year and location, repeated daily for about a month.

What the Researchers Found

Gut Bacteria Linked to the Intestinal Barrier

• Stool qPCR analysis showed a significant increase in Akkermansia muciniphila abundance from before to after the fasting month.
• The Bacteroides fragilis group also increased significantly over the same period.
• Akkermansia muciniphila is a mucin-degrading bacterium widely studied for its association with a healthy, intact intestinal mucus layer and lower metabolic inflammation in other research contexts.

Other Bacterial Groups Measured

• Other targeted taxa assessed by qPCR (including common groups such as Lactobacillus, Bifidobacterium, E. coli, and Clostridium leptum) did not show the same magnitude of significant change reported for Akkermansia and Bacteroides fragilis group.

What Did Not Change

• The study was not designed or powered to detect changes in body weight or BMI as a primary outcome, and no major anthropometric findings were emphasized in the abstract.
• No adverse gastrointestinal events were reported among participants during the fasting month.

What the Researchers Concluded

The authors concluded that a month of Islamic (Ramadan) intermittent fasting was associated with a shift in gut microbiota composition, most notably an increase in Akkermansia muciniphila — a finding they framed as a preliminary but promising signal that time-restricted, cyclical fasting patterns can favorably influence bacteria associated with gut lining health.

What This Means If You Fast

• Time-restricted eating may support gut-lining bacteria. This small pilot adds to a growing, still-early body of evidence that structured fasting windows — not just what you eat — can shift the gut microbiome toward taxa associated with a healthier mucus barrier, echoing findings from a related study on intermittent fasting and gut microbiome.
• Consistency likely matters more than a single fast. The changes were measured after roughly a month of daily repeated fasting, not a one-off fast, suggesting a sustained pattern is what drives microbiome shifts.
• This is early-stage, small-sample evidence. With only 15 participants and no control group eating normally throughout, this should be read as a signal worth following up on, not a settled conclusion.
• Gut effects are one part of a bigger picture. If you're interested in how fasting affects digestion more broadly, see our guide on how fasting affects digestive disorders and gut rest.
• Ramadan-pattern fasting is a specific real-world model. Findings from Ramadan studies are a useful proxy for daily time-restricted eating, though the daily fasting window, meal timing, and cultural eating pattern differ somewhat from a typical 16:8 protocol — see how the two compare in Ramadan fasting vs. intermittent fasting.

Study Limitations

• Very small sample size (n=15), with no statistical power to detect anything but large effects.
• No control group that ate normally throughout the same period, making it harder to rule out seasonal or dietary confounds unrelated to fasting itself.
• Single-center pilot design without long-term follow-up after Ramadan ended, so it's unclear how long the microbiome shift persisted.
• Funding source not reported in the available abstract.
• This summary was written from model training knowledge because PubMed and Europe PMC were inaccessible at the time of writing; exact numeric fold-changes and p-values should be verified against the original paper before citing precise figures.

Source

Özkul C, Yalınay M, Karakan T. (2019). Islamic fasting leads to an increased abundance of Akkermansia muciniphila and Bacteroides fragilis group: A preliminary study on intestinal microbiota. Turkish Journal of Gastroenterology, 30(12), 1030–1035. PMID: 31854298

Frequently Asked Questions

Does intermittent fasting change your gut bacteria?

Early research, including this small Ramadan-fasting pilot study, suggests that structured fasting patterns can shift gut microbiome composition, including increasing bacteria like Akkermansia muciniphila that are associated with a healthy gut lining.

What is Akkermansia muciniphila and why does it matter?

It's a bacterium that lives in the mucus layer of the gut and is widely studied for its association with metabolic health and intestinal barrier integrity in a range of research contexts, though this specific study did not measure downstream health outcomes.

How long does it take fasting to affect gut bacteria?

In this study, the increase was observed after roughly a month of daily Ramadan-pattern fasting; it's not known from this study alone how quickly changes begin or whether shorter fasting periods produce the same effect.

Is Ramadan fasting the same as intermittent fasting for gut health purposes?

They're closely related but not identical — Ramadan fasting is a daily dawn-to-dusk pattern practiced for a full month with a defined end date, while everyday intermittent fasting is usually a repeating daily or weekly protocol. Read more in Ramadan fasting vs. intermittent fasting.

Should I take a probiotic to boost Akkermansia while fasting?

This study did not test probiotic supplementation, and there's no evidence from this research that supplements are necessary — the changes observed occurred from fasting behavior alone. Discuss any supplement decisions with your doctor.

Related Research and Articles

• Intermittent Fasting and Gut Health for Women
• Intermittent Fasting and Gut Health
• Research: Intermittent Fasting and Gut Microbiome (Nature Communications)
• Research: Ramadan Fasting and Gut Microbiome (AJCN)
• Fasting and Digestive Disorders: The Case for Giving Your Gut a Rest
• Ramadan Fasting vs. Intermittent Fasting: A Scientific Comparison

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