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Conversion of cholesterol to coprostanol by the intestinal microflora during the first two years of human life
1Department of Medical Microbial Ecology, Karolinska Institute, Stockholm, Sweden.
Insights
The gut microflora
Area of Science:
- Microbiology
- Pediatrics
- Biochemistry
Background:
- Cholesterol conversion to coprostanol by gut microflora is crucial.
- Understanding the establishment of this conversion in infants is important for health.
- Previous studies have not fully elucidated the timeline and influencing factors in early life.
Purpose of the Study:
- To investigate the establishment of cholesterol to coprostanol conversion in healthy Swedish infants.
- To determine the age of onset and influencing factors, such as breastfeeding, on this microbial conversion.
- To characterize conversion rates and patterns throughout the first two years of life.
Main Methods:
- Fecal samples were collected from 25 healthy Swedish children at multiple time points from birth to 24 months.
- Gas-chromatographic analysis was used to measure cholesterol and coprostanol levels.
- Statistical analysis was performed to correlate conversion rates with age and feeding practices.
Main Results:
- Microbial conversion of cholesterol to coprostanol began in the second half of the first year for most infants.
- Breastfeeding delayed the initiation of conversion; prolonged breastfeeding correlated with lower conversion rates at 12 months.
- By 24 months, children showed varied conversion patterns: 13 stable high, 3 stable low, and 6 unstable converters.
Conclusions:
- The establishment of cholesterol to coprostanol conversion is a developmental process influenced by infant feeding practices, particularly breastfeeding.
- Breastfeeding appears to delay and potentially influence the long-term rate of this critical microbial conversion.
- Individual variations in conversion rates are established by the second year of life, suggesting a complex interplay of factors.
Abstract:
The establishment of the conversion of cholesterol to coprostanol by the intestinal microflora was followed in 25 healthy Swedish children by gas-chromatographic analysis of fecal samples taken at 0, 1, 3, 6, 9, 12, 15, 18, 21, and 24 months of age. In 15 children, the microbial conversion of cholesterol to coprostanol started during the second half of the first year of life. During the second year of life, a sequestered distribution of the conversion rate could be distinguished. At the end of the study, 13 of the children were stable high converters, 3 were stable low converters, and 6 were unstable converters while the conversion pattern of three children could not be determined. The initiation of the establishment of conversion was delayed by breast-feeding, and only one child had coprostanol in feces while still being breast-fed. Those children exclusively breast-fed for more than 4 months or weaned after 6 months of age had significantly lower conversion rates at 12 months of age than did the other children (p < 0.05). Once conversion started, previous breast-feeding tended to result in a stable, later high rate of conversion of cholesterol. Between 6 and 15 months of age, the conversion rate increased with age, but after standardization for the period of exposure to foods other than breast milk, no age factor could be identified.