PubMed Health⌕ Search

PubMed · 17077076

Intestinal colonisation, microbiota and future probiotics?

Abstract

The human intestine is colonized by a large number of microorganisms, collectively termed microbiota, which support a variety of physiological functions. As the major part of the microbiota has not yet been cultured, molecular methods are required to determine microbial composition and the impact of specific dietary components including probiotics. Probiotics are viable microbial food supplements, which have a beneficial impact on human health. Health-promoting properties have been demonstrated for specific probiotic products. The most significant demonstrations for probiotic efficacy include prevention and treatment of antibiotic associated diarrhea, rotavirus diarrhea and allergy prevention. Lactobacillus rhamnosus GG (=ATCC 53103) and Bifidobacterium lactis Bb12 are the among the best-characterized and most studied probiotic strains with demonstrated impact on human health. New complex targets for probiotics include irritable bowel syndrome and Helicobacter pylori infection. For future probiotics the most important target is a demonstrated clinical benefit supported by knowledge on the mechanistic actions in the microbiota of the target population. Molecular and genomics-based knowledge of the composition and functions of the microbiota, as well as deviations from the balanced microbiota, will advance the selection of new and specific probiotics. Potential combinations of specific probiotics may prove to be the next step to reduce the risk on intestinal diseases and reconstruct specific microbial deviations.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Seppo Salminen, Yoshimi Benno, Willem de Vos. 2006. Intestinal colonisation, microbiota and future probiotics?. https://pubmed.ncbi.nlm.nih.gov/17077076/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Clinical evaluation of a new starter formula for infants containing live Bifidobacterium longum BL999 and prebiotics.

OBJECTIVES: The larger number of bifidobacteria in the intestine of breast-fed infants has been associated with their better health compared with formula-fed infants. We assessed the safety and tolerability of an experimental formula containing 2 x 10(7) colony-forming units of Bifidobacterium longum BL999 and 4 g/L of a prebiotic mixture containing 90% galacto-oligosaccharides and 10% fructo-oligosaccharides. METHODS: A 7-mo prospective, randomized, reference-controlled, double-blinded trial was performed in infants who were not breast fed after the 14th day of birth. One hundred thirty-eight infants were enrolled and assigned to receive the control or experimental formula until they were 112 d old. Mean weight gain (primary outcome) and recumbent length, head circumference, tolerability (gastrointestinal symptoms), and overall morbidity (secondary outcomes) were measured at 14, 28, 56, 84, and 112 d of age. RESULTS: Equivalence in mean weight gain between the two groups was shown. The treatment difference in the intention-to-treat and per-protocol populations were within the predefined equivalence boundaries of +/-3.9 g/d. No statistically significant difference in recumbent length, head circumference, or incidence of adverse events was found between the two groups. Infants in the experimental group had fewer incidences of constipation and had stool characteristics that suggest that the experimental formula was tolerated well. Furthermore, these infants showed a trend toward fewer respiratory tract infections. CONCLUSIONS: The starter formula containing BL999 and galacto-oligosaccharides/fructo-oligosaccharides is safe and well-tolerated.

Bifidobacterium↗

Sugar transport systems of Bifidobacterium longum NCC2705.

Here we present the complement of the carbohydrate uptake systems of the strictly anaerobic probiotic Bifidobacterium longum NCC2705. The genome analysis of this bacterium predicts that it has 19 permeases for the uptake of diverse carbohydrates. The majority belongs to the ATP-binding cassette transporter family with 13 systems identified. Among them are permeases for lactose, maltose, raffinose, and fructooligosaccharides, a commonly used prebiotic additive. We found genes that encode a complete phosphotransferase system (PTS) and genes for three permeases of the major facilitator superfamily. These systems could serve for the import of glucose, galactose, lactose, and sucrose. Growth analysis of NCC2705 cells combined with biochemical characterization and microarray data showed that the predicted substrates are consumed and that the corresponding transport and catabolic genes are expressed. Biochemical analysis of the PTS, in which proteins are central in regulation of carbon metabolism in many bacteria, revealed that B. longum has a glucose-specific PTS, while two other species (Bifidobacterium lactis and Bifidobacterium bifidum) have a fructose-6-phosphate-forming fructose-PTS instead. It became obvious that most carbohydrate systems are closely related to those from other actinomycetes, with a few exceptions. We hope that this report on B. longum carbohydrate transporter systems will serve as a guide for further in-depth analyses on the nutritional lifestyle of this beneficial bacterium.

Bifidobacterium↗

Molecular characterization of Bifidobacterium longum biovar longum NAL8 plasmids and construction of a novel replicon screening system.

In this study, we performed molecular characterization and sequence analysis of three plasmids from the human intestinal isolate Bifidobacterium longum biovar longum NAL8 and developed a novel vector screening system. Plasmids pNAL8H (10 kb) and pNAL8M (4.9 kb) show close sequence similarity to and the same gene organization as the already characterized B. longum plasmids. The B. longum plasmid pNAC1 was identified as being most closely related to pNAL8L (3.5 kb). However, DNA sequence analysis suggested that direct repeat-rich sites could have promoted several recombination events to diversify the two plasmid molecules. We verified the likely rolling circle replication of plasmid pNAL8L and studied the phylogenetic relationship in all the Bifidobacterium plasmids fully sequenced to date based on in silico comparative sequence analysis of their replication proteins and iteron regions. Our transformation experiments confirmed that the ColE1 replication origin from high-copy-number pUC vectors could interfere with the replication apparatus of Bifidobacterium plasmids and give rise to false positive clones. As a result, we developed a system suitable for avoiding possible interference by other functional replication modules on the vector and for screening functional replicons from wild-type plasmids.

Bifidobacterium↗