Can a Course of Antibiotics Change Your Blood Sugar?

How antibiotics may affect blood sugar through the gut microbiome

Dr Adithya V. Naragund, Senior Consultant in GI & HPB Surgery at Cytecare Hospitals, Bengaluru, tells indianexpress.com, “The gut microbiome plays a significant role in regulating glucose metabolism, insulin sensitivity, inflammation, and energy extraction from food. Beneficial gut bacteria produce short-chain fatty acids that help maintain the intestinal barrier, reduce systemic inflammation, and support healthy insulin function. When antibiotics disrupt this microbial balance, there can be temporary changes in these metabolic pathways.”

Emerging research suggests that antibiotic-induced alterations in the gut microbiome may influence blood sugar regulation, Dr Naragund states, although the extent varies between individuals. Most healthy people are unlikely to experience clinically significant changes, but temporary shifts in glucose metabolism have been observed, particularly when broad-spectrum antibiotics substantially alter microbial diversity. These effects are generally reversible once the microbiome begins to recover.

Who is most likely to notice blood sugar changes?

Individuals with diabetes, prediabetes, insulin resistance, or existing metabolic dysfunction are more likely to notice fluctuations in blood glucose levels during or after antibiotic treatment. In these individuals, even minor disruptions in insulin sensitivity or inflammation can have a more noticeable impact on glycaemic control.

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“It is also important to recognise that infections themselves can raise blood sugar levels through stress hormone responses, making it difficult to separate the effects of the illness from those of the antibiotic. Some broad-spectrum antibiotics may have a greater impact on gut microbial diversity because they affect a wider range of bacterial species. However, the overall metabolic effect depends on multiple factors, including the duration of treatment, the individual’s baseline health, dietary habits, and the specific antibiotic prescribed,” shares Dr Naragund

Supporting gut recovery after antibiotics

Quick Quiz

See if you can answer this:

What is one of the best ways to support your gut microbiome after completing a course of antibiotics?

A. Avoid all fibre-rich foods until your digestion returns to normal.

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B. Eat a diverse, fibre-rich diet with foods such as fruits, vegetables, legumes, whole grains, nuts and seeds, and include fermented foods where appropriate.

C. Take antibiotics again to restore the balance of gut bacteria.

D. Assume everyone’s gut recovers at the same speed.

Reveal the answer

✅ Correct answer: B

“Recovery of the gut microbiome differs from person to person and may take weeks or even months. A varied diet rich in plant-based, fibre-containing foods helps nourish beneficial gut bacteria, while fermented foods such as curd and yoghurt may also support recovery. In some situations, probiotics can be useful, but their benefits depend on the strain and the individual. Regular physical activity and avoiding unnecessary antibiotic use also contribute to long-term gut health,” states Dr Naragund.

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Antibiotics and blood sugar: Can they temporarily affect glucose metabolism?

Can antibiotics affect blood sugar levels? An expert explains how antibiotics may temporarily alter the gut microbiome, influence glucose metabolism and whether people with diabetes or prediabetes should be concerned.

How antibiotics may affect blood sugar through the gut microbiome

Who is most likely to notice blood sugar changes?

Supporting gut recovery after antibiotics

Quick Quiz