Dietary interventions targeting the gut microbiota have emerged as a promising approach for preventing or improving metabolic disorders, such as type 2 diabetes. Among various functional foods, yogurt has gained particular attention as it is widely consumed and may influence both the gut microbial ecosystem and host metabolism.
However, there have been limited studies that evaluated the effects of yogurt consumption on gut microbiota composition and blood glucose fluctuation patterns in daily life using continuous glucose monitoring (CGM).
This is especially important because recent reports stated that even in people with normal average blood glucose levels and blood glucose waveform amplitude, the risk of diabetic complications increases when blood glucose waveforms no longer fluctuate smoothly.
In collaboration with THE PHAGE Inc and Chiba University, Meiji Co Ltd conducted a single-arm, 84-day intervention study that is supported by the Japan Society for the Promotion of Science and Manpei Suzuki Diabetes Foundation.
It was found that daily probiotic-fermented yogurt consumption was associated with improvements in glucose dynamics (state of blood glucose control) and significant remodeling of the gut microbiota.
These findings suggest the potential role of the gut microbiome in modulating the metabolic effects of yogurt and underscore the value of personalized dietary strategies.
The results of this research was recently published in The Journal of Nutrition, and an oral presentation was given at the 69th Annual Meeting of the Japan Diabetes Society on May 22.
Study design
This study involved 303 Japanese adults without a prior diabetes diagnosis. The participants consumed 200g of yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 (LB2038) and Streptococcus thermophilus 1131 (ST1131) strains daily at breakfast for 84 days.
CGM data was acquired at 15-minute intervals using FreeStyle Libre, and three parameters were used to evaluate glucose dynamics—mean blood glucose level, glucose waveform amplitude (SD), and glucose waveform smoothness (AC_Var).
The gut microbiota was analyzed using 16S rRNA gene analysis of stool samples before and after intervention, while background factors such as clinical laboratory values and genetic indicators associated with type 2 diabetes were also examined.
Gut microbiota changes
Following continued consumption of the yogurt by the study participants, all three indicators of CGM showed significant improvement.
Specifically, mean glucose levels decreased progressively, with a reduction of 4.06mg/dL (95% confidence interval (CI): 2.97mg/dL, 5.14mg/dL) by the final period.
Significant decreases were also observed in SD (-0.86mg/dL; 95% CI: -1.32mg/dL, -0.41mg/dL) and AC_Var (-0.0059; 95% CI: -0.010, -0.0017).
Several baseline gut bacterial genera, including Gemmiger, Veillonella, Alistipes, and Butyricicoccus, were significantly associated with changes in the CGM-derived measurements.
In addition, increases were observed in the genera Blautia, Faecalibacterium, and Coprococcus, as well as in the phylum Firmicutes, whereas decreases were noted in Prevotella, Oscillospira, and the phylum Bacteroidetes.
While clinical test values and genetic indicators were not significantly associated with individual differences in blood glucose response, the study suggested that individuals with a higher level of butyrate-producing bacteria (such as Faecalibacterium, Coprococcus, and Butyricicoccus) before starting intake may experience a greater improvement in blood glucose dynamics.
“These results suggest that yogurt consumption may be useful in the pre-diabetic stage and could potentially lead to individualized intervention strategies based on gut microbiota,” the researchers concluded.
Source: The Journal of Nutrition. doi: doi.org/10.1016/j.tjnut.2026.101572. “Associations between Yogurt Consumption, Gut Microbiota Composition, and Glucose Dynamics: A Single-Arm 84-Day Intervention Study Using Continuous Glucose Monitoring”. Authors: Hikaru Sugimoto, et al.
