Association of Gut Microbiota Enterotypes with Blood Trace Elements in Women with Infertility

Abstract

Infertility is defined as failure to achieve pregnancy within 12 months of unprotected intercourse in women. Trace elements, a kind of micronutrient that is very important to female reproductive function, are affected by intestinal absorption, which is regulated by gut microbiota. Enterotype is the classification of an intestinal microbiome based on its characteristics. Whether or not Prevotella-enterotype and Bacteroides-enterotype are associated with blood trace elements among infertile women remains unclear. The study aimed to explore the relationship between five main whole blood trace elements and these two enterotypes in women with infertility. This retrospective cross-sectional study recruited 651 Chinese women. Whole blood copper, zinc, calcium, magnesium, and iron levels were measured. Quantitative real-time PCR was performed on all fecal samples. Patients were categorized according to whole blood trace elements (low levels group, <5th percentile; normal levels group, 5th‒95th percentile; high levels group, >95th percentile). There were no significant differences in trace elements between the two enterotypes within the control population, while in infertile participants, copper (P = 0.033), zinc (P < 0.001), magnesium (P < 0.001), and iron (P < 0.001) in Prevotella-enterotype was significantly lower than in Bacteroides-enterotype. The Chi-square test showed that only the iron group had a significant difference in the two enterotypes (P = 0.001). Among infertile patients, Prevotella-enterotype (Log(P/B) > −0.27) predicted the low levels of whole blood iron in the obesity population (AUC = 0.894; P = 0.042). For the high levels of iron, Bacteroides-enterotype (Log(P/B) <−2.76) had a predictive power in the lean/normal group (AUC = 0.648; P = 0.041) and Log(P/B) <−3.99 in the overweight group (AUC = 0.863; P = 0.013). We can infer that these two enterotypes may have an effect on the iron metabolism in patients with infertility, highlighting the importance of further research into the interaction between enterotypes and trace elements in reproductive function.

Genetic Insights into Intestinal Microbiota and Risk of Infertility: A Mendelian Randomization Study

“…In our MR analysis, both Bacteroides and Bacteroidaceae showed protective effects on male fertility, indicating the potential role of Bacteroides in the management of infertile males. It has been found that Bacteroides might affect the iron metabolism in infertile females, highlighting the links between Bacteroides and reproductive function [ 33 ]. Several species of Bacteroides were detected to be correlated with non-obstructive azoospermia in male infertility [ 34 ].…”

Maternal and infant microbiome: next-generation indicators and targets for intergenerational health and nutrition care

“…The heterogeneous community properties of the gut microbiome suggest different metabolic function and responses to the same food in digestive tract, which may eventually influence the maternal and infant metabolism. Two enterotypes of gut microbiome were classified based on 651 Chinese pregnant women, which are separately dominated by Bacteroides , Prevotella ( Yao et al, 2022 ). Differences in taxonomic composition imply that enterotypes may differ in functional and ecological properties.…”