Related Experiment Videos
Bacterially synthesized folate in rat large intestine is incorporated into host tissue folyl polyglutamates
1Vitamin Bioavailability Laboratory, U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.
Abstract:
Unlike mammalian tissues, certain intestinal microflora are capable of de novo synthesis of folate. To explore the availability of bacterially synthesized folate to the host organism, we used [3H] p-aminobenzoic acid (3H PABA) to label folate newly synthesized by the intestinal microflora. Labeled folates were isolated by affinity chromatography and identified by ion-pair HPLC. In this study [3H]PABA was injected into rat cecum to determine whether the [3H]folate synthesized by bacteria appeared in rat liver and other tissues. Rats were kept in sling suits to prevent coprophagy. Ion-pair chromatography of the purified liver folate demonstrated that bacterially derived [3H]folate was incorporated into all host liver-specific folate polyglutamates, mostly penta- and hexaglutamyl derivatives. Similar results were observed in kidney folates. These data provide direct evidence that some of the folate synthesized by the microflora in the rat large intestine is incorporated into the tissue folate of the host.
Insights
Intestinal bacteria synthesize folate, which can be utilized by the host. This study shows bacterial folate is incorporated into rat liver and kidney tissues, demonstrating host-microbe nutrient transfer.
Area of Science:
- Microbiology
- Nutritional Science
- Gastroenterology
Background:
- Mammalian tissues cannot synthesize folate de novo.
- Intestinal microflora possess the capability for folate synthesis.
Purpose of the Study:
- To investigate the host's ability to utilize folate synthesized by intestinal bacteria.
- To trace the incorporation of bacterially synthesized folate into host tissues.
Main Methods:
- Rats were administered [3H] p-aminobenzoic acid (3H PABA) into the cecum to label newly synthesized folate by microflora.
- Prevented coprophagy using sling suits.
- Isolated and identified labeled folates using affinity chromatography and ion-pair HPLC.
Main Results:
- Bacterially derived [3H]folate was detected in rat liver and kidney tissues.
- The labeled folate was incorporated into host liver-specific folate polyglutamates, primarily penta- and hexaglutamyl derivatives.
Conclusions:
- Provides direct evidence that folate synthesized by intestinal microflora is incorporated into host tissues.
- Demonstrates a functional transfer of nutrients from gut bacteria to the host organism.