Enterotypes in asthenospermia patients with obesity

Area of Science:

• Human Gut Microbiome Research
• Reproductive Medicine
• Nutritional Science

Background:

• Enterotypes, classifications of the gut microbiome, may influence health outcomes, including reproductive health.
• The gut microbiome composition, characterized by Prevotella and Bacteroides abundance, can be stratified into distinct enterotypes.
• Previous research suggests a link between diet, the gut microbiome, and disease risk, but the specific impact on male fertility requires further investigation.

Purpose of the Study:

• To investigate the correlation between body mass index (BMI) and asthenospermia (reduced sperm quality) within different gut microbiome enterotypes.
• To determine if enterotype classification can serve as an individualized index for assessing the risk of asthenospermia associated with obesity.
• To analyze the differential impact of obesity on sperm quality parameters in men with Prevotella-dominant (P) versus Bacteroides-dominant (B) enterotypes.

Main Methods:

• Analysis of 407 stool samples to determine gut microbiome enterotypes (P/B ratio) in men.
• Stratification of participants into enterotype P (P/B ≥ 0.01) and enterotype B (P < 0.01) groups, further categorized by normal weight and overweight/obese status.
• Statistical analysis, including odds ratios (OR) and confidence intervals (CI), to assess the association between obesity, BMI, and sperm quality parameters (forward progressive motility, total motility).

Main Results:

• In the enterotype P group, obesity was a significant risk factor for reduced forward progressive sperm motility (OR 3.350) and total sperm motility (OR 4.298).
• Obesity remained an independent risk factor for asthenospermia in enterotype P even after adjusting for follicle-stimulating hormone.
• In contrast, no significant association between obesity and impaired sperm quality parameters was observed in the enterotype B group.

Conclusions:

• Gut microbiome enterotype P is associated with increased risk of asthenospermia in overweight/obese men.
• BMI serves as a significant risk factor for asthenospermia specifically in men with enterotype P, but not in enterotype B.
• Enterotype classification offers a potential individualized approach to understanding the relationship between obesity and male fertility.