The intestinal tract of adult carries 1–2kg of microbes. It is a common knowledge that pathogenic microbes could cause infectious diseases such as diarrheal, while others are associated with inflammatory and allergic diseases [1–3].
On the other hand, the majority of the gut microbes do protect us from pathogens via colonization resistance, modulation of immunity, and benefit us through digestion of foods and production of vitamins. Thus it is logical to assume that the supplementation of selected microbes could impart beneficial effect to us and they are termed probiotics. The FAO/WHO have defined probiotics living microorganisms which when administered in adequate amounts confer a health benefit on the host .
Factors determining the microbial colonization of human intestinal tract
We are born with a sterile gastrointestinal tract (GI), its colonization begin at birth. The GI microbiota profile is determined by a number of factors:
Scientific and clinically demonstrated probiotic effects
The following summarizes scientific and clinically demonstrated beneficial effects of selected probiotics.
Human gut home for a complex consortium of 1013 to 1014 bacterial cells, outnumber the body cells of the host by a factor of 10. Gut microbiota and its microbiome should be considered a fluidized genetic and metabolic component of us. Thus harnessing functionality of probiotics as ingredient of functional foods is a desirable approach in the promotion of health and disease prevention.
CGMP is a glycopeptide containing sialic cyp450 inducers discovered by Delfour in 1965 . It is a polypeptide fragment of κ-casein (κ-CN, a unique sugar composition in CN) in milk. During the production process of cheese, rennet casein can hydrolyze the Phe-Met peptide bond of κ-CN in milk to generate insoluble sub-κ-CN (the 1–105 amino acid residual part of the peptide chain) and soluble polypeptide (106–169 amino acid residual part of the peptide chain). Such polypeptide containing a large number of carbohydrates is called glycomacropeptide. Correspondingly, the glycomacropeptide from casein is named as casein glycomacropeptide (CGMP). During the past decade, CGMP, as a bioactive component, has attracted extensive attention due to its unique chemical and functional properties. Its most promising applications are to inhibit hemagglutinin of influenza virus, inhibit the secretion of gastric juice, promote the proliferation of , and modulate the response of immune systems . In recent years, under the continuous support by the National Natural Science Foundation of China, our research group has systematically investigated the effect of CGMP on the regulation of the intestinal immune system, and the change of intestinal flora and intestinal inflammatory reactions. Our investigations have confirmed the anti-informatory activity of CGMP, which can improve, alleviate and cure inflammatory bowel diseases (IBD) to some extents . However, the specific anti-inflammatory activity and corresponding clear mechanisms of CGMP still need further investigation to explore its effect on relevant immune molecules and immune signaling pathways, which will be beneficial for further elucidating the mechanism of IBD treatment.
NF-κB is discovered by Baltimore from Cancer Research Center of Massachusetts Institute and Rwiansen from Biomedical Research of Whitehead Institute at MIT in 1986, as a transcription factor widely present in mammalian cells. It can bind to the specific site of a promoter or an enhancer to promote the transcription and expression of a variety of genes, which can regulate apoptosis, cell adhesion, cell proliferation, natural and adaptive immune response, inflammation, stress response and intracellular tissue remodeling processes . The ubiquitous distribution of NF-κB in the body has gained more and more attention, and NF-κB has become an important treatment target of many diseases . The nuclear translocation of p65 is the signal for NF-κB activation, and the initiation of physiological and pathological changes of NF-κB. The content of p65 in cells is extremely low, but it can contact with DNA extensively due to its high affinity to DNA. Therefore, p65 is highly efficient and accurate in recognizing target sites. In addition, nuclear transfer can be achieved through the dissociation of p65 and IκB without the requirement of new protein synthesis process. Thus it may induce fast gene transcription, and is involved in the transcriptional regulation of instant genes associated with stress defense responses . Furthermore, CGMP plays an important role in the nuclear translocation of p65 during NF-κB activation or inhibition process. If CGMP inhibits the starting point of a series of cascade reactions, CGMP can subsequently terminate the pathophysiological processes.