A new simple test for evaluation of intestinal bacteria

Area of Science:

• Microbiology
• Gastroenterology
• Biochemistry

Background:

• Assessing enteric bacteria is crucial for diagnosing gastrointestinal conditions.
• Current methods for evaluating intestinal microorganisms can be complex, expensive, or require specialized equipment.
• A need exists for a simpler, more accessible method to assess gut microbial activity.

Purpose of the Study:

• To investigate the suitability of a newly synthesized ursodeoxycholic acid-para-aminobenzoic acid (PABA-UDCA) conjugate for evaluating enteric bacteria.
• To determine if PABA-UDCA can be selectively deconjugated by intestinal microorganisms.

Main Methods:

• Synthesized a PABA-UDCA conjugate designed for selective deconjugation.
• Tested the conjugate's deconjugation by various microorganisms, comparing it to glycocholic acid hydrolysis.
• Administered PABA-UDCA orally to rats with normal gut flora, bacterial overgrowth, and after antibiotic treatment, measuring urinary PABA excretion.

Main Results:

• PABA-UDCA was deconjugated by cholylglycine hydrolase, releasing free PABA, but was resistant to pancreatic and intestinal mucosal enzymes.
• Most microorganisms capable of splitting glycocholic acid also deconjugated PABA-UDCA.
• Urinary PABA excretion was significantly higher in rats with bacterial overgrowth and significantly lower in rats treated with antibiotics, correlating with microbial load.

Conclusions:

• The PABA-UDCA conjugate serves as a reliable substrate for evaluating the activity of intestinal microorganisms.
• This method provides a simple and rapid way to assess the intestinal microbial environment.
• The PABA-UDCA assay avoids the need for radioisotopes or expensive, specialized apparatus, making it widely accessible.