A dietary intervention for postmenopausal hot flashes: A potential role of gut microbiome Original paper

What was studied?

This exploratory study investigated the impact of a low-fat, plant-based dietary intervention including daily cooked soybeans on the frequency and severity of postmenopausal hot flashes, with a particular focus on the role of the gut microbiome. The study aimed to identify microbial changes associated with symptom improvements, especially changes in bacteria known to influence estrogen metabolism and inflammation.

Who was studied?

The study enrolled 84 postmenopausal women aged 40–65 years experiencing at least two moderate-to-severe hot flashes per day. Participants were randomly assigned either to follow the dietary intervention or to continue their usual diets for 12 weeks. Gut microbiome analyses using deep shotgun metagenomic sequencing were conducted on stool samples from a subset of 11 women from the intervention group, collected before and after the dietary period.

Most important findings

The dietary intervention resulted in a dramatic 95% reduction in total hot flashes and a 96% decrease in moderate-to-severe hot flashes. Significant decreases were observed in both daytime and nighttime hot flashes. Although overall microbial diversity (alpha and beta diversity) did not change significantly, specific taxa exhibited changes in relative abundance. Notably, decreases in Porphyromonas and Prevotella corporis correlated with reductions in severe daytime hot flashes, and decreases in Clostridium asparagiforme correlated with reductions in total severe and severe nighttime hot flashes. These bacteria are linked to inflammatory pathways and estrogen metabolism. Increases in genera such as Erysipelatoclostridium, Fusicatenibacter, and Holdemanella, known for anti-inflammatory effects and fiber fermentation, were also observed. The plant-based diet rich in fiber and soy isoflavones likely modulated the microbiome to reduce systemic inflammation and improve estrogen receptor-mediated signaling, contributing to symptom relief. However, after correction for multiple testing, these associations were not statistically significant, highlighting the exploratory nature of the findings.

Key implications

This study provides preliminary evidence linking dietary modulation of the gut microbiome to reductions in menopausal vasomotor symptoms. The findings suggest that plant-based diets with soy may beneficially alter gut bacteria involved in inflammation and estrogen metabolism, offering a potential non-hormonal therapeutic avenue for hot flash management. Larger, controlled studies are necessary to confirm these microbiome-symptom relationships and to explore personalized dietary strategies targeting gut microbiota for menopausal symptom relief.