Can Gut Flora Predict Diabetes Remission After Bariatric Surgery?

A new study reveals that the composition of gut flora before obesity surgery could influence the disappearance of type 2 diabetes after the operation. Researchers analyzed the bacteria present in the intestines of forty-six patients suffering from severe obesity and diabetes before they underwent sleeve gastrectomy, a common procedure to reduce the stomach. One year after the surgery, some patients saw their diabetes disappear while others did not.

The results show that the overall diversity of gut bacteria did not differ significantly between these two groups. However, a specific measure of the balance between bacterial species was higher in those whose diabetes did not remiss. More interestingly, certain bacteria were more present in the patients who recovered. This is particularly true for bacteria such as Eggerthella and Flavonifractor, which play a role in sugar metabolism. Conversely, other bacteria like Fusicatenibacter and Holdemanella were more abundant in those whose diabetes persisted.

Gut flora refers to all the microorganisms living in the digestive tract. These microbes help digest food, produce beneficial substances, and influence the immune system. Their imbalance is often associated with metabolic diseases such as diabetes. Scientists also observed that patients on insulin treatment before surgery were less likely to recover from diabetes. Additionally, metabolic pathways related to carbohydrate transformation were more active in those whose diabetes disappeared.

These findings suggest that analyzing gut flora before surgery could help predict which patients will benefit most from the intervention. This could become a complementary tool to the clinical criteria already used, such as the duration of diabetes or blood sugar levels. The study thus paves the way for more personalized medicine, where each patient’s bacterial profile would be taken into account to optimize outcomes.

Researchers emphasize that these bacteria could act by altering how the body uses sugars and produces certain hormones. For example, Eggerthella has already been linked to metabolic disorders, while other bacteria such as Ruminococcaceae seem to promote better blood sugar control. These mechanisms would explain why some patients respond better to surgery than others.

This approach could also help better understand why sleeve gastrectomy is so effective against diabetes. By identifying favorable bacterial profiles, doctors could one day tailor treatments or recommend targeted interventions to improve the chances of remission. Further research is needed to confirm these results and explore their application in clinical practice.

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Study Citation

DOI: https://doi.org/10.1007/s11695-026-08612-6

Title: Gut Microbiota-specific Profile Prior to Surgery for Predicting Type 2 Diabetes Remission in Patients Undergoing Sleeve Gastrectomy

Journal: Obesity Surgery

Publisher: Springer Science and Business Media LLC

Authors: José Ignacio Martínez-Montoro; Raquel Sancho-Marín; Lourdes Garrido-Sánchez; Luis Ocaña-Wilhelmi; Rocío Soler-Humanes; Nerea Ruiz-Campos; María José García-López; Francisco J Tinahones; Carolina Gutiérrez-Repiso