Bengt E. Gustafsson memorial lecture. Function of the normal human microflora.

Area of Science:

• Microbiology
• Gastroenterology
• Metabolic Engineering

Background:

• The human microflora comprises trillions of bacteria, influencing nutrient metabolism, vitamin synthesis, and the processing of drugs, hormones, and carcinogens.
• Specific microflora enzymes are implicated in metabolizing endogenous hormones and activating colon carcinogens.
• Our research focuses on the interplay between gut microflora, estrogen, and cholesterol metabolism, as well as carcinogen activation.

Purpose of the Study:

• To investigate methods for modulating the enzymatic activities of the human gut microflora.
• To assess the impact of dietary changes, antibiotic administration, and probiotic supplementation on microflora function.
• To explore strategies for optimizing beneficial microflora activities.

Main Methods:

• Dietary intervention: Switching from an omnivore to a vegetarian diet.
• Pharmacological intervention: Administration of antibiotics.
• Probiotic intervention: Supplementation with a human strain of Lactobacillus.

Main Results:

• A vegetarian diet significantly decreased bacterial deconjugating enzymes in the intestine.
• Antibiotic administration suppressed the metabolic activity of the gut microflora.
• Lactobacillus supplementation achieved similar suppressive effects on microflora metabolic activity.

Conclusions:

• The composition and activity of the human gut microflora can be intentionally altered.
• Dietary shifts, antibiotics, and specific probiotics offer viable methods to modulate microflora enzymatic functions.
• Targeted manipulation of the gut microflora holds potential for maximizing beneficial activities and influencing host health.