Related Experiment Video
Updated: May 16, 2026
04:41
Measuring Lactase Enzymatic Activity in the Teaching Lab
Published on: August 6, 2018
Selective carbohydrate utilization by lactobacilli and bifidobacteria
D Watson1, M O'Connell Motherway, M H C Schoterman
1Alimentary Pharmabiotic Centre, Department of Microbiology, University College Cork, Cork, Ireland.
Journal of Applied Microbiology
|December 18, 2012
Summary
Galacto-oligosaccharides (GOS) and lactulose best supported the growth of gut bacteria like lactobacilli and bifidobacteria. This research aids in selecting prebiotics for synbiotic development.
Area of Science:
- Microbiology
- Nutrition Science
- Gastroenterology
Background:
- Lactobacilli and bifidobacteria are key gut commensals.
- Understanding their growth requirements is crucial for gut health.
- Specific carbohydrates act as prebiotics, influencing microbial populations.
Purpose of the Study:
- To assess the growth-promoting capabilities of various carbohydrates for lactobacilli and bifidobacteria.
- To compare the efficacy of commercially available carbohydrate products.
- To investigate interspecies variations in carbohydrate metabolism.
Main Methods:
- Tested 68 bacterial strains (29 lactobacilli, 39 bifidobacteria) against 10 carbohydrates.
- Analyzed growth using optical density (OD600), final pH, fermentation products, and growth rates.
- Quantified microbial consumption of galacto-oligosaccharides (GOS) using chromatography.
Main Results:
- Galacto-oligosaccharides (GOS) and lactulose demonstrated the most favorable growth support.
- Inulin, maltodextrin, and polydextrose showed poor growth promotion for both bacterial groups.
- Mixtures like GOS/inulin and fructo-oligosaccharides (FOS)/inulin yielded results comparable to their individual components.
Conclusions:
- Carbohydrate structure significantly impacts lactobacilli and bifidobacteria growth.
- GOS and lactulose are effective prebiotics for these beneficial gut bacteria.
- Findings facilitate rational design of synbiotics by matching bacteria with optimal prebiotics.
Related Concept Videos
01:27Microbiota of the Large Intestine
The large intestine hosts the most densely populated microbial ecosystem in the human body. This complex community primarily consists of anaerobic bacteria, with Bacillota (formerly Firmicutes) and Bacteroidota (formerly Bacteroidetes) as the predominant groups. The distribution of these microbes varies along different sections of the large intestine, influenced by local environmental factors such as oxygen availability and nutrient composition.The cecum, located at the beginning of the large...
01:25Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...
01:25Carbohydrate Absorption
Carbohydrates are essential macronutrients that serve as the body's primary energy source. Their digestion begins in the mouth, where salivary amylase partially breaks down complex carbohydrates such as starch into smaller oligosaccharides. This mechanical and enzymatic activity prepares carbohydrates for further processing in the gastrointestinal tract.
After being swallowed, the partially digested carbohydrates mix with gastric secretions in the stomach. However, the acidic environment...
After being swallowed, the partially digested carbohydrates mix with gastric secretions in the stomach. However, the acidic environment...
01:27Microbes in the Production of Fermented Foods
Lactic acid bacteria (LAB) and molds are instrumental in fermenting plant-based foods to enhance preservation and ensure year-round availability. These microbial processes convert plant carbohydrates into organic acids and other metabolites that inhibit spoilage organisms and contribute to the sensory qualities of the final product.In sauerkraut production, cabbage goes through a microbial succession that starts with cocci such as Leuconostoc mesenteroides. These microbes begin fermentation by...
01:36Carbohydrate Metabolism
Carbohydrates are polymers composed of molecules containing atoms of carbon, hydrogen and oxygen. One gram of carbohydrate can provide four kilo-calories of energy, which makes it the most efficient instant energy source.
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
00:57Carbohydrate Digestion
Carbohydrate digestion and metabolism break down simple and complex carbohydrates from food into saccharides (i.e., sugars) for the body to use as energy. Carbohydrate digestion starts in the mouth during mastication, or chewing. The masticated carbohydrates remain intact in the stomach. Digestion resumes in the duodenum of the small intestine, where pancreatic alpha-amylase and brush border enzymes of the microvilli convert complex carbohydrates to monosaccharides. Finally, the monosaccharides...